solar eclipse 21st june 2020 · solar eclipse, 21st june 2020 likely impacts and preparedness- a...
TRANSCRIPT
Indian Power System likely impacts and preparedness - A report
SOLAR ECLIPSE st21 June 2020
Power System Operation Corporation Ltd.Power System Operation Corporation Ltd.(A Government of India Enterprise)(A Government of India Enterprise)
Power System Operation Corporation Ltd.(A Government of India Enterprise)
May 2020May 2020May 2020
SOLAR ECLIPSE st
21 June 2020
Power System Operation Corporation Ltd.(A Government of India Enterprise)
Indian Power System likely impacts and preparedness - A report
May 2020
Solar eclipse, 21st June 2020 likely impacts and Preparedness- A report Page 1 of 99
Table of Contents Executive Summary ................................................................................................................................ 6
Chapter - 1 : Annular eclipse- 21.06.2020 ....................................................................................... 9
Chapter - 2 : Indian power system -an overview ........................................................................ 12
Chapter - 3 : All India weather scenario in June 2020 .............................................................. 13
3.1 Analysis of impact of monsoon(weather) on solar generation in June 2019 ... 14
Chapter - 4 : Pre event analysis of annular solar eclipse on 21.06.2020 ........................... 16
4.1 Projected trajectory of the solar eclipse .................................................................... 16
4.2 Forecasting of photo voltaic generation and ramp rate ........................................ 17
Chapter - 5 : Forecasted all India and Regional demand ......................................................... 33
Chapter - 6 : System reliability study for 21st June 2020 solar eclipse ............................... 39
Chapter - 7 : Operational Planning .................................................................................................. 43
7.1 Northern Region ........................................................................................................................ 43
7.2 Western Region ......................................................................................................................... 49
7.3 Southern Region ........................................................................................................................ 54
Chapter - 8 : Utility scale solar power plant controller ............................................................ 61
Chapter - 9 : Summary and Recommendations ........................................................................... 63
Annexure- I .............................................................................................................................................. 67
Annexure- II ............................................................................................................................................. 71
Annexure- III ........................................................................................................................................... 72
Annexure- IV ............................................................................................................................................ 81
Annexure- V ............................................................................................................................................. 83
Annexure- VI ............................................................................................................................................ 84
Annexure- VII .......................................................................................................................................... 85
Annexure- VIII ......................................................................................................................................... 88
Annexure- IX ............................................................................................................................................ 90
Annexure- X ............................................................................................................................................. 94
Annexure- XI ............................................................................................................................................ 97
Disclaimer ................................................................................................................................................ 99
Solar eclipse, 21st June 2020 likely impacts and Preparedness- A report Page 2 of 99
List of Figures
Figure 1: Path of annular solar eclipse on 21st June 2020 ............................................................................. 6
Figure 2: Annular solar eclipse of June 21, 2020 ......................................................................................... 10
Figure 3: Solar Eclipse - Beginning and Ending time ................................................................................... 11
Figure 4: All India installed capacity (MW) as on 31.03.2020 .................................................................... 12
Figure 5: Advance of southwest monsoon 2020 .......................................................................................... 14
Figure 6:All India solar generation June 2019 ............................................................................................. 15
Figure 7: Location of solar PV power plants & path of the solar eclipse ................................................... 16
Figure 8: All India estimated solar generation on 21st June 2020 .............................................................. 20
Figure 9: All India normal vs estimated solar generation ramp rate on 21st June 2020 .......................... 21
Figure 10: Northern Region estimated solar generation on 21st June 2020 ............................................. 22
Figure 11: Western Region estimated solar generation on 21st June 2020 ............................................... 23
Figure 12: Southern Region estimated solar generation on 21st June 2020 .............................................. 24
Figure 13: Rajasthan estimated solar generation on 21st June 2020 ......................................................... 25
Figure 14: Punjab estimated solar generation on 21st June 2020 .............................................................. 26
Figure 15: Uttar Pradesh estimated solar generation on 21st June 2020 .................................................. 26
Figure 16: Estimated solar generation connected to ISTS in Northern Region ........................................ 27
Figure 17: Gujarat estimated solar generation on 21st June 2020 ............................................................. 27
Figure 18: Maharashtra estimated solar generation on 21st June 2020 .................................................... 28
Figure 19: Madhya Pradesh estimated solar generation on 21st June 2020 .............................................. 28
Figure 20: Chhattisgarh estimated solar generation on 21st June 2020 .................................................... 29
Figure 21: Estimated solar generation connected to ISTS in Western Region .......................................... 29
Figure 22: Andhra Pradesh estimated solar generation on 21st June 2020............................................... 30
Figure 23: Karnataka estimated solar generation on 21st June 2020 ........................................................ 30
Figure 24: Tamil Nadu estimated solar generation on 21st June 2020 ...................................................... 31
Figure 25: Telangana estimated solar generation on 21st June 2020 ........................................................ 31
Figure 26: Estimated solar generation connected to ISTS in Southern Region......................................... 32
Figure 27: Eastern Region demand from 21st July 2009 to 23rd July 2009 ................................................ 33
Figure 28: Southern Region demand from 14th January 2010 to 16th January 2010 ................................ 34
Figure 29: All India demand from 24th December 2019 to 26th December 2019 ...................................... 34
Figure 30: All India estimated demand on 21st June 2020 .......................................................................... 35
Figure 31: Northern Region estimated demand on 21st June 2020............................................................ 36
Figure 32: Western Region estimated demand on 21st June 2020 ............................................................. 36
Figure 33: Southern Region estimated demand on 21st June 2020 ............................................................ 37
Figure 34: Eastern Region estimated demand on 21st June 2020 .............................................................. 37
Figure 35 : North Eastern Region estimated demand on 21st June 2020 .................................................. 38
Figure 36: Northern Region average cold and hot reserve ......................................................................... 43
Figure 37: Northern Region gas generation schedule on 21st June 2020 ................................................. 44
Figure 38: Energy Content (MU) on last day of the month for the years 2018-19 to 2020-21................ 45
Figure 39: Northern Region hydro generation schedule on 21st June 2020 .............................................. 46
Figure 40: Western Region reserve requirement on 21st June 2020 ......................................................... 49
Figure 41: Southern Region estimated demand on 21st June 2020 ............................................................ 54
Figure 42: SR Energy Content as on last day of the month for the years 2018-19 to 2020-21 ............... 55
Solar eclipse, 21st June 2020 likely impacts and Preparedness- A report Page 3 of 99
Figure 43: Day wise Southern Region hydro generation for June-19 and May 2020 ............................... 55
Figure 44: Southern Region estimated solar generation on 21st June 2020 .............................................. 57
Figure 45:Northern Region normal vs estimated solar generation ramp rate on 21st June 2020 ........... 72
Figure 46:Western Region normal vs estimated solar generation ramp rate on 21st June 2020 ............ 72
Figure 47: Southern Region normal vs estimated solar generation ramp rate on 21st June 2020 .......... 73
Figure 48: NR ISTS connected solar normal vs estimated ramp rate on 21st June 2020 .......................... 73
Figure 49:WR ISTS connected solar normal vs estimated ramp rate on 21st June 202 ............................ 74
Figure 50 : SR ISTS connected solar normal vs estimated ramp rate on 21st June 2020 .......................... 74
Figure 51: Rajasthan normal vs estimated solar generation ramp rate on 21st June 2020 ...................... 75
Figure 52: Punjab normal vs estimated solar generation ramp rate on 21st June 2020........................... 75
Figure 53: Uttar Pradesh normal vs estimated solar generation ramp rate on 21st June 2020 ............... 76
Figure 54: Gujarat normal vs estimated solar generation ramp rate on 21st June 2020 ......................... 76
Figure 55: Maharashtra normal vs estimated solar generation ramp rate on 21st June 2020 ................. 77
Figure 56: Madhya Pradesh normal vs estimated solar generation ramp rate on 21st June 2020 .......... 77
Figure 57: Chhattisgarh normal vs estimated solar generation ramp rate on 21st June 2020 ............... 78
Figure 58 : Andhra Pradesh normal vs estimated solar generation ramp rate on 21st June 2020 .......... 78
Figure 59: Karnataka normal vs estimated solar generation ramp rate on 21st June 2020 ..................... 79
Figure 60: Tamil Nadu normal vs estimated solar generation ramp rate on 21st June 2020 ................... 79
Figure 61 : Telangana normal vs estimated solar generation ramp rate on 21st June 2020 .................... 80
Solar eclipse, 21st June 2020 likely impacts and Preparedness- A report Page 4 of 99
List of Tables
Table 1 : Details of obscuration( %) in major cities of India ........................................................................ 9
Table 2: Details of % obscuration for State and ISTS connected solar plants ........................................... 19
Table 3: Average solar generation ramp rate of State & ISTS connected solar on 21st June 2020 ......... 21
Table 4: All India and Region wise estimated solar generation ................................................................. 39
Table 5: Inter-regional drawls and margin on 23rd June 2019 ................................................................... 39
Table 6: Region wise considered demand in power system simulation study case ................................. 40
Table 7: Inter-regional flow in base case and eclipse case ......................................................................... 41
Table 8: Voltages at buses near large solar parks........................................................................................ 42
Table 9: Northern Region ISGS gas based stations ...................................................................................... 44
Table 10: Northern Region ISGS hydro generating stations ....................................................................... 46
Table 11: Rajasthan hydro generating stations ........................................................................................... 47
Table 12: Uttar Pradesh hydro generating stations .................................................................................... 48
Table 13: Punjab hydro generating stations ................................................................................................ 48
Table 14: Average available reserves in WR ISGS stations on 18th June 19 to 25th June 19 ..................... 50
Table 15: Western Region ISGS Gas and Thermal stations ......................................................................... 50
Table 16: Western Region ISGS and state hydro generating stations ........................................................ 51
Table 17: Average reserve available in Southern Region ISGS stations on 17th to 22nd June19 .............. 56
Table 18: Andhra Pradesh hydro generating stations ................................................................................ 58
Table 19: Karnataka hydro generating stations .......................................................................................... 58
Table 20: Telangana hydro generating stations .......................................................................................... 59
Table 21: Tamil Nadu hydro generating stations ........................................................................................ 60
Table 22: Northern and Western Region ISGS generating plants (Gas and Hydro) ................................. 64
Solar eclipse, 21st June 2020 likely impacts and Preparedness- A report Page 5 of 99
List of Acronyms
ATC: Available Transfer Capability
CEA: Central Electricity Authority
FGMO: Free Governor Mode Operation
IST: Indian Standard Time (UTC+05:30Hrs)
ISTS: Inter State Transmission System
ISGS: Inter State Generating Station
IEGC: Indian Electricity Grid Code
IMD: India Meteorological Department
LGBR: Load Generation Balance Report
NLDC: National Load Dispatch Centre
NR: Northern Region
NRLDC: Northern Regional Load Despatch Centre
NER: North Eastern Region
POSOCO: Power System Operation Corporation Ltd.
PPC: Power Plant Controller
PV: Photo Voltaic
RRAS: Reserve Regulation Ancillary Services
RE: Renewable Energy
RSD: Reserve Shutdown
REMC: Renewable Energy Management Centre
RLDC: Regional Load Dispatch Centre
SCED: Security Constrained Economic Despatch
SLDC: State Load Dispatch Centre
SR: Southern Region
SCADA: Supervisory Control and Data Acquisition
SIL: Surge Impedance Loading
STATCOM: Static Synchronous compensator
SVC: Static VAR Compensator
WR: Western Region
WRLDC: Western Regional Load Despatch Centre
Solar eclipse, 21st June 2020 likely impacts and Preparedness- A report Page 6 of 99
Executive Summary
India will be experiencing annular solar eclipse on 21st June 2020. Annularity will be visible in
the states of Rajasthan, Punjab, Haryana, Himachal Pradesh, Uttarakhand with maximum
obscuration1 of around 99% and other parts of country will experience partial solar eclipse.
The annular solar eclipse will begin at 09:56 AM IST at Dwarka, Gujarat and will end at 14:29
PM IST at Dibrugarh, Assam. The path of annularity is as shown in the Figure.1
Figure 1: Path of annular solar eclipse on 21st June 2020
During solar eclipse the Sun is partially/fully covered by the Moon, as a result there will be
reduction in solar irradiance and hence corresponding reduction in power generation from
1 Eclipse Obscuration - Eclipse obscuration is the fraction of the Sun’s area occulted by the Moon. It should not be confused with eclipse magnitude, which is the fraction of the Sun’s diameter occulted by the Moon. Eclipse obscuration may be expressed as either a percentage or a decimal fraction (e.g., 50% or 0.50).
New Delhi 93.8 %
Kolkata 65.5 %
Bangalore 36.2 %
Mumbai 62.1 %
Solar eclipse, 21st June 2020 likely impacts and Preparedness- A report Page 7 of 99
solar PV cells. As on 31st March 2020, with installed capacity of 34.6 GW 2 solar PV constitutes
9% of total installed generation capacity of Indian grid. Electricity Grids with such a significant
penetration of solar capacity will be adversely impacted by astronomical events such as solar
eclipse, due to variation in solar generation (reduction followed by rise in generation) and
associated large ramp rates. Maintaining load generation balance and system voltages within
pre-specified IEGC band in the grid are the important tasks of system operator during solar
eclipse. Variation of solar generation disturbs load generation balance (LGB) leading to
deviation of grid frequency from the nominal and the same needs to be maintained by flexing
fast ramping sources like Hydro and Gas generating stations. Low generation from solar power
parks results in high voltages at pooling substations, which needs to be maintained by timely
switching of Reactors/ Transmission lines. Meticulous planning exercise involving following
steps is required for mitigating the impact and maintaining grid stability.
1. Assessment of eclipse impact on solar power generation
a. Irradiance data of previous solar eclipse(26th December 2019) for various solar
parks were analysed to understand the impact of solar eclipse on irradiance w.r.t
% of obscuration. This data along with solar installed capacity growth and solar
generation data of March 2019/June 2019 and March 2020 is used for assessing
the impact. As onset of monsoon is expected on June 1st, weather at some of the
solar park sites in the country may be cloudy on the eclipse day and this will also
play important role for assessing the impact. However, by assessing the impact
w.r.t clear sky, system operators are actually preparing for worst possible
scenario. Reassessment of the impact 2 or 3 days prior to eclipse day would
provide accurate impact.
2. Electricity demand forecast for the period
a. From previous eclipse day demand pattern, it is observed that electricity demand
during the eclipse period will be less compared to normal day due to suspension
of some of the activities during this period. After end of the eclipse there may be
sudden rise in demand due to restarting of human activities. 21st June 2020 being
a Sunday demand would be 3-4 % lower on all India basis compared to a working
2 State wise installed capacity of grid Interactive Renewable power as on 31st March 2020 https://mnre.gov.in/the-ministry/physical-progress
Solar eclipse, 21st June 2020 likely impacts and Preparedness- A report Page 8 of 99
day. Demand for eclipse day is forecasted based on previous eclipse experience
and conditions prevailing in the grid during June.
3. Operation planning for maintaining load generation balance (LGB) in the grid
a. Planning of fast ramping sources like Hydro and Gas for compensating the
variations in solar generation.
4. Maintaining the voltages at pooling substations.
a. Switching of bus/line reactors at pooling stations and nearby substations
b. Ensuring that STATCOMs, SVCs are in service and put in voltage control mode
c. Switching of transmission lines if required further
5. Coordination across different utilities of the power system
Solar eclipse 21st June 2020 at a glance:
Parameters Values Type of eclipse/date Annular /21st June 2020 Solar eclipse start time (For India) 09:56 AM (Dwarka) Maximum eclipse time 11:50 AM Solar eclipse end time (For India) 14:29 PM (Dibrugarh, Assam) Visibility of annularity Northern part of India Maximum % of Obscuration 98.66% (Chamoli, Uttarakhand)
All India estimated solar generation reduction at the time of maximum solar eclipse w.r.t. normal day (assuming clear sky conditions)
11943 MW at 11:50 AM
Northern Region estimated solar generation reduction at the time of maximum solar eclipse w.r.t. normal day (assuming clear sky conditions)
4514 MW at 11:47 AM
Western Region estimated solar generation reduction at the time of maximum solar eclipse w.r.t. normal day (assuming clear sky conditions)
2720 MW at 11:50 AM
Southern Region estimated solar generation reduction at the time of maximum solar eclipse w.r.t. normal day (assuming clear sky conditions)
4721 MW at 11:50 AM
All India average solar generation ramp down rate 102 MW/Minute
All India average solar generation ramp up rate 104 MW/Minute
* Solar eclipse impact assessment is done by assuming clear sky conditions which is the worst
possible scenario. June being a monsoon season in India, solar generation is likely to be
impacted by cloud cover on solar eclipse day.
Solar eclipse, 21st June 2020 likely impacts and Preparedness- A report Page 9 of 99
Chapter - 1 : Annular eclipse- 21.06.2020
On 21st June 2020, our country will be experiencing annular eclipse, annularity will be visible
in Northern states like Rajasthan, New Delhi, Punjab, Western Uttar Pradesh and Uttarakhand.
Rest of the country will be experiencing partial eclipse of Sun. The annular eclipse will begin at
09:56 AM IST at Dwarka, Gujarat and will end at 14:29 PM IST at Dibrugarh, Assam. This large
annular eclipse will cover over 99% of the sun, lasts for 38 seconds at the point of maximum
eclipse, creating a narrow path of 21 km wide.
The solar eclipse start time, end time and the maximum obscuration for various locations are
obtained from Positional Astronomy Centre, Indian Metrological Department3. From this data
source, 85 locations data for partial eclipse and six locations data for annular eclipse has been
captured throughout the country. For each state, the available location nearest to the
geographical location of the major solar plants have been selected. Details of such locations are
attached at Annexure-I. Further, Figure 2 and 3 shows the path of annular solar eclipse of 21st
June 2020 and eclipse beginning & ending time across the country respectively.
Details of obscuration (%), eclipse start time, maximum eclipse time and end time in major
cities of India are given below: -
S. No. City Obscuration
(%)
Eclipse
Start Time
Maximum
Eclipse Time
Eclipse End
Time
1 New Delhi 93.8 10:20 12:01 13:48
2 Ahmedabad 77.2 10:03 11:42 13:32
3 Mumbai 62.1 10:00 11:37 13:27
4 Kolkata 65.5 10:46 12:35 14:17
5 Hyderabad 50.3 10:14 11:55 13:44
6 Bengaluru 36.5 10:13 11:47 13:31
7 Chennai 34.2 10:22 11:59 13:41
8 Trivandrum 23.2 10:14 11:40 13:15
Table 1 : Details of obscuration( %) in major cities of India
3 The Partial and Annular eclipse start, end time and the maximum obscuration location: http://www.packolkata.gov.in/eclipse.php
Solar eclipse, 21st June 2020 likely impacts and Preparedness- A report Page 10 of 99
4
Figure 2: Annular solar eclipse of June 21, 2020
Solar eclipse, 21st June 2020 likely impacts and Preparedness- A report Page 11 of 99
5
Figure 3: Solar Eclipse - Beginning and Ending time
4 Image source: http://www.packolkata.gov.in/eclipse.php 5 Image Source: http://www.packolkata.gov.in/eclipse.php
Solar eclipse, 21st June 2020 likely impacts and Preparedness- A report Page 12 of 99
Chapter - 2 : Indian power system -an overview
Indian electricity grid is one of the largest synchronous grid in the world, The Indian electricity
grid has total installed generating capacity of around 370 GW6 comprising of 230.60 GW of
Thermal, 45.67 GW of Hydro, 87.03 GW of Renewable and 6.78 GW of Nuclear Generation.
Figure 4: All India installed capacity (MW) as on 31.03.2020
The installed capacity of ground mounted solar generation is 32112 MW and rooftop solar is
2515 MW (as on 31st March 2020). Out of this, around 2285 MW of ground mounted solar and
2515 MW total capacity of rooftop solar generation is not telemetered (Annexure-II). For
secure and reliable operation of the grid, data telemetry from solar plants is very important
with increase in capacity over time.
6 All India Installed Capacity (in MW) of Power Stations-
http://cea.nic.in/reports/monthly/installedcapacity/2020/installed_capacity-03.pdf
205135 MW, 55%
87027.68MW, 24%
45699 MW, 12%
24955MW, 6.7%
6780 MW , 1.8%
510 MW,0.1%
All India Source-wise Installed Capacity (370106 MW)
Coal +Lignite RES Hydro
Gas Nuclear Diesel
37693 MW, 43%
34628 MW, 40%
10023 MW, 12%
4683 MW, 5%
All India RE Capacity Mix (87027 MW)
WindSolarBiomass Power/Cogen/Waste to EnergySmall Hydro
Solar eclipse, 21st June 2020 likely impacts and Preparedness- A report Page 13 of 99
Chapter - 3 : All India weather scenario in June 2020
Southwest monsoon enters in Indian sub-continent through Andaman and Nicobar Islands
around 20th May and covers central Bay of Bengal by 25th May. Subsequently, it advances in to
the mainland of India through Kerala. The normal date of monsoon onset over Kerala is 1st June
and then it continues to cover entire country from south to north and from east to west. Once
arrived in Kerala, it also covers parts of its adjacent states like Tamil Nadu and Rayalaseema
and also some parts from north-eastern states like Tripura, Nagaland, Manipur and Mizoram.
By 5th June, monsoon covers parts of Karnataka, Andhra Pradesh and reaches to south
Maharashtra and entire north east India. Monsoon advances up to Mumbai along with regions
from West Bengal, Sikkim, Assam, Meghalaya and most parts from the Arunachal Pradesh
around 10th June. It covers further north and northwest parts of the country (parts of Gujarat
and Kutch, Madhya Pradesh, Bihar and east Uttar Pradesh) by 15th June. On 1st July,
advancement of monsoon takes place almost over most parts of east Rajasthan, Punjab,
Haryana, Delhi, Uttarakhand, west Uttar Pradesh, and Jammu and Kashmir. Climatologically,
southwest monsoon covers entire country (remaining parts of northwest India) by 15th July.
Southwest monsoon normally stays in the country for four months (June to September).
India Meteorological Department (IMD) had released new normal dates of onset (Fig.5) and
withdrawal of southwest monsoon based on recent data in a press release dated 15th April
2020.The normal dates of onset are revised based on data during 1961-2019 and normal dates
of withdrawal are revised based on data during 1971-2019. Now the detailed report (CRS
Research Report. No. 3/2020) on the new normal dates of monsoon onset and withdrawal is
ready and given in the below link.
http://www.imdpune.gov.in/Clim_Pred_LRF_New/Reports.html
As per the new normal, the monsoon sets over Kerala around 1st June, nearly same as the
existing normal date and covers the entire country one week before the existing normal.
However, monsoon withdrawal from northwest India is delayed by more than 2 weeks
compared to the existing normal date (i.e. 1st September). Monsoon retreats from most parts
of the country except south Peninsula and some parts of neighbouring central India by 15th
October coinciding with the existing normal and subsequently northeast monsoon gets
established over south Peninsula.
Solar eclipse, 21st June 2020 likely impacts and Preparedness- A report Page 14 of 99
7
Figure 5: Advance of southwest monsoon 2020
As per above forecast by IMD southwest monsoon enters India by 1st June and hence the
probability of sky being clear at solar park locations of Southern Region and Western Region
on 21st June 2020 is less. However, clear sky conditions may prevail on 21st June 2020 in
Northern Region.
3.1 Analysis of impact of monsoon (weather) on solar generation in June 2019
To observe the impact of weather on solar generation, data for the month of June 2019 has been
analysed. Three sets of data have been considered for analysis purpose.
1) Average solar generation of 5 to 6 clear sky days in the month of June 19
7 Image Source: Press release by IMD on Advance of southwest monsoon into south Andaman Sea https://mausam.imd.gov.in/backend/assets/press_release_pdf/PRESS_RELEASE_17_May_20202.pdf
Solar eclipse, 21st June 2020 likely impacts and Preparedness- A report Page 15 of 99
2) Average solar generation of 5th to 20th June 19
3) Average solar generation of 5 to 6 cloudy days in the month of June 19
The plot of all India solar generation for June 2019 is given below: -
Figure 6:All India solar generation June 2019
Upon analysis, it was found that on All India basis there was a reduction of 14% in solar
generation between a clear sky day and a cloudy day. On regional basis, the reduction was 11.90
%, 12.01% and 19.7 % for Northern Region, Southern Region and Western Region respectively.
In view of weather conditions, day ahead forecast will be very important. Day ahead forecast
may be generated through REMC/in-house model for all regions /states considering the
weather conditions and solar eclipse obscuration factor. Solar eclipse impact assessment is
done by assuming clear sky conditions which is the worst possible scenario.
0
3000
6000
9000
12000
15000
18000
00
:00
00
:52
01
:44
02
:36
03
:28
04
:20
05
:12
06
:04
06
:56
07
:48
08
:40
09
:32
10
:24
11
:16
12
:08
13
:00
13
:52
14
:44
15
:36
16
:28
17
:20
18
:12
19
:04
19
:56
20
:48
21
:40
22
:32
23
:24
Sola
r ge
ner
atio
n in
MW
Time
All India Solar Generation June 2019
Average solar geneartion of 5 to 6 clear sky days Average solar generation of 5.06.19 to 20.06.19
Average solar generation of 5 to 6 cloudy days
Solar eclipse, 21st June 2020 likely impacts and Preparedness- A report Page 16 of 99
Chapter - 4 : Pre event analysis of annular solar eclipse on 21.06.2020
4.1 Projected trajectory of the solar eclipse
With the help of Google earth8 and geo coordinates, the path of the solar eclipse has been drawn
and major solar power plants have been geographically located on Indian map [Figure 7]. Based
on the above mapping, it is estimated that about 7127 MW solar PV of generation will fall in
more than 85 % of obscuration zone, 7927 MW will fall in 60-85 % of obscuration zone ,15646
MW will fall in 30-60% of obscuration zone and 3928 MW will fall in less than 30 % of
obscuration zone.
Figure 7: Location of solar PV power plants & path of the solar eclipse
8Jubier, Xavier, Annular Solar Eclipse on 21.06.2020 in India
http://xjubier.free.fr/en/site_pages/SolarEclipsesGoogleEarth.html
Solar eclipse, 21st June 2020 likely impacts and Preparedness- A report Page 17 of 99
4.2 Forecasting of photo voltaic generation and ramp rate
Previously, India experienced an annular solar eclipse on 26th December 2019. At that time
annularity was visible mainly in Southern India i.e. in the states of Kerala, Tamil Nadu and
Karnataka while the rest of the country witnessed partial eclipse of the sun.
During above event 6.5 GW9 of solar generation reductions took place with respect to 25th
December 2019 and average ramp down rate was 11.6 MW/minute from 08:03 hrs to 09:30
hrs and average ramp up rate was 123 MW/minute from 09:30 hrs to 11:20 hrs.
During estimation of solar generation in above solar eclipse, State wise mean obscuration was
considered for calculation of solar generation reduction and it was also assumed that solar
generation will start reducing linearly when obscuration starts but after post event analysis,
it was observed that there was a time shift in estimated and actual generation and GHI at plants
which experienced annular eclipse, started reducing when obscuration was more than 10%.
However, in case of plants which experienced partial eclipse, GHI started reducing when
obscuration reached around 18-20%. The time shift in estimated and actual solar generation
can be attributed to the methodology of considering the mean obscuration of each state for
solar generation, which did not take into cognisance the factor of diversity in the geographical
spacing of various generating units within the physical boundaries of each state.
Based on the above experience, the methodology for estimation of solar generation during solar
eclipse 21st June 2020 is upgraded to hybrid approach.
METHODOLOGY ADOPTED TO FORECAST SOLAR GENERATION DURING ECLIPSE
Steps followed for estimating the solar eclipse impact are as follows:
1. Solar generation data from SCADA for the months of Mar-19, June-19 and Mar-20 has
been utilized for estimation of solar generation in June-20.
2. The average of 5 to 6 clear sky days data from each month has been considered for
estimation.
3. To eliminate the time shift in generation, June-19 data has been taken as base data.
9 Solar Eclipse 26th December 2019 Analysis of its impact on Indian Power System-A report
https://posoco.in/wp-content/uploads/2020/02/Solar-Eclipse-26th-December-2019-Analysis-of-its-imapct-on-Indian-Power-System-A-report.pdf
Solar eclipse, 21st June 2020 likely impacts and Preparedness- A report Page 18 of 99
4. Based on the data, reduction in solar generation from Mar-19 and June-19 is observed
due to temperature and cloud cover. From this reduction factor has been calculated
between March-19 to June-19.
5. Further, growth factor (for accounting of growth in solar installed capacity) has been
calculated between June-19 to March-20 to scale up solar generation to tune of Mar-20
with time shift.
6. Above anticipated generation has been scaled up and scaled down with a factor between
June-19 to March-20 and June-19 to March-19 to obtain true generation of June’20.
7. The obscuration of major solar plant of each state and ISTS solar plants has been taken
for calculation.
8. For estimating the impact on state wise solar generation mean obscuration of solar
plants located in the state has been considered and for ISTS generators plant wise
available obscuration has been considered. The details of solar eclipse start time,
maximum time, end time and % of obscuration for states and ISTS connected solar
plants are tabulated below: -
State/ISTS
Connected Solar
plants
Solar eclipse
start time
Maximum
eclipse
time
End of Solar
eclipse time
Obscuration
(%)
Andhra Pradesh 10:14:47 11:52:47 13:38:52 42%
Karnataka 10:09:24 11:45:30 13:32:04 43 %
Tamil Nadu 10:17:27 11:47:18 13:25:49 27%
Telangana 10:16:04 11:57:46 13:46:09 52%
Pavagada Solar Park
(ISTS Connected) 10:11:38 11:47:49 13:33:40 40%
NP Kunta Solar Park
(ISTS connected) 10:15:16 11:52:14 13:37:21 39%
Gujarat 10:01:41 11:38:46 13:28:30 80%
Maharashtra 10:07:50 11:47:22 13:37:13 60%
Madhya Pradesh 10:12:14 11:54:01 13:43:58 76%
Solar eclipse, 21st June 2020 likely impacts and Preparedness- A report Page 19 of 99
State/ISTS
Connected Solar
plants
Solar eclipse
start time
Maximum
eclipse
time
End of Solar
eclipse time
Obscuration
(%)
RUMS
(ISTS connected) 10:26:21 12:12:34 14:00:08 75%
Rajasthan 10:09:07 11:47:04 13:34:54 94%
Punjab 10:18:22 11:58:03 13:44:06 98%
Uttar Pradesh 10:23:00 12:08:00 13:56:00 80%
Solar plants at Bhadla (ISTS connected)
10:08:11 11:45:39 13:33:23 94%
Solar plant at Bikaner (ISTS connected)
10:11:52 11:50:22 13:37:42 96%
Table 2: Details of % obscuration for State and ISTS connected solar plants
9. Generation of solar plant in each state has been reduced linearly based on percentage of
obscuration, start and end timings of eclipse. At the time of maximum obscuration of
eclipse, the generation has been considered minimum and in proportion to obscuration.
10. After maximum solar eclipse, generation from solar plants have been increased linearly
based on solar eclipse obscuration and time.
11. Further, based on the experience from previous solar eclipse, for the solar plants or
states which are falling in path of annularity or more than 80 % obscuration, generation
has been reduced by 3% for initial 10 % of obscuration and then generation has been
reduced linearly till time of maximum solar eclipse occurred. After maximum solar
eclipse, generation from solar plant has been increased linearly and for last 10 % of
obscuration only 3 % of generation has been increased.
12. Solar plant or state which are comings in path of partial eclipse or less than 80 %
obscuration, generation has been reduced linearly by 3% for initial 15 % of obscuration
and after that generation has been reduced linearly till the time of maximum solar
eclipse occurred. After maximum solar eclipse, generation from solar plant is increased
linearly and for last 15% of obscuration 3 % of generation only increased.
Based on the above methodology, solar generation has been estimated for the solar rich
states as well as ISTS connected solar generators separately and added to arrive at regional
and all India solar generation.
Solar eclipse, 21st June 2020 likely impacts and Preparedness- A report Page 20 of 99
Figure 8 shows all India expected feed-in from solar power plants on 21st June 2020 considering
clear sky conditions, with and without solar eclipse.
Figure 8: All India estimated solar generation on 21st June 2020
It is estimated that eclipse would lead to reduction of all India solar generation by
approximately 11943 MW at maximum obscuration time i.e. 11:50 hrs and total estimated
reduction in energy would be 20 MU w.r.t. a normal day. All India solar generation will start
reducing from 17315 MW at 10:02 hrs to 8415 MW at 11:50 hrs with average ramp down rate
is 102 MW/Minute and after the maximum eclipse, the solar generation will increase from 8415
MW at 11:50 hrs to 18777 MW at 13:58 hrs with average ramp rate of 104 MW/Minute.
During initial period, approximately 8900 MW of solar generation will reduce in very short span
of time i.e 1:48 hrs and after maximum eclipse, it will increase by 10362 MW within 2:08 hrs.
This variation in solar generation will pose serious threat to system security and challenge to
system operators to maintain load and generation balance during the eclipse period i.e. 09:56
hrs (Dwarka) to 14:29 hrs (Dibrugarh).
To maintain the load generation balance during solar eclipse period, 11943 MW generation
from other sources i.e Thermal, Hydro and Gas is required to be ramped up during reduction of
solar generation time and after maximum solar eclipse, the generation from other sources is
required to be ramped down in line with the variations in solar generation.
17315 MW at 10:02 hrs
8415 MW at 11:50 hrs
18777 MW at 13:58hrs
0
5000
10000
15000
20000
5:4
6
6:1
7
6:4
8
7:1
9
7:5
0
8:2
1
8:5
2
9:2
3
9:5
4
10
:25
10
:56
11
:27
11
:58
12
:29
13
:00
13
:31
14
:02
14
:33
15
:04
15
:35
16
:06
16
:37
17
:08
17
:39
18
:10
18
:41
19
:12
Sola
r G
ener
atio
n in
MW
Time
All India estimated solar generation on 21st June 2020 Generation during clear sky condition Estimated generation during solar eclipse Difference
11943 MW
Solar eclipse, 21st June 2020 likely impacts and Preparedness- A report Page 21 of 99
All India solar generation ramp rate during solar eclipse under clear sky condition is shown in
figure 9. It is estimated that average solar generation ramp down rate would be around 102
MW per minute for 1 hour 48 minutes and ramp up rate would be 104 MW per minute for 2
hours and 8 minutes. The estimated maximum solar generation ramp down rate is 184
MW/minute at 11:25 hrs and maximum ramp up rate is 186 MW/minute at 13:02 hrs.
Figure 9: All India normal vs estimated solar generation ramp rate on 21st June 2020
Average solar generation ramp rate of State and ISTS connected solar generation is summarised
below: -
Table 3: Average solar generation ramp rate of State & ISTS connected solar on 21st June 2020
-184
186
-230
-130
-30
70
170
5:4
66
:16
6:4
67
:16
7:4
68
:16
8:4
69
:16
9:4
61
0:1
61
0:4
61
1:1
61
1:4
61
2:1
61
2:4
61
3:1
61
3:4
61
4:1
61
4:4
61
5:1
61
5:4
61
6:1
61
6:4
61
7:1
61
7:4
61
8:1
61
8:4
61
9:1
6
MW
/Min
ute
Time
All India Solar Generation Ramp Rate
Actual ramp rate during clear sky condition Estimated ramp rate during solar eclipse
State/ISTS connected
solar power plants
Average solar generation
ramp down rate MW/
Minute
Average solar generation
ramp up rate MW/Minute
Andhra Pradesh 8 08 Karnataka 10 09 Tamil Nadu 05 07 Telangana 09 09 Gujarat 11 12 Madhya Pradesh 07 07 Maharashtra 03 04 Rajasthan 19 20 Punjab 04 04 Uttar Pradesh 03 03 SR ISTS connected solar 08 08 WR ISTS connected solar 04 04 NR ISTS connected solar 15 14
Solar eclipse, 21st June 2020 likely impacts and Preparedness- A report Page 22 of 99
Region, State and ISTS connected solar generation ramp rate for per minute is given as per Annexure III. Figure 10 shows expected feed-in from solar in Northern Region on 21st June 2020 under clear
sky conditions, with and without solar eclipse
Figure 10: Northern Region estimated solar generation on 21st June 2020
The states of Rajasthan, New Delhi, Punjab, Western Uttar Pradesh and Uttarakhand in
Northern Region will observe annular solar eclipse. Rajasthan is renewable rich state and major
solar plants of Northern Region are located in this state. In Northern Region, Punjab will
observe maximum obscuration of 98.77 % followed by Rajasthan of 95 % then Uttar Pradesh
of 80%. It is estimated that solar generation reduction in Northern region is likely to be 4514
MW at the time of maximum obscuration w.r.t. normal day. During the eclipse, solar generation
in Northern region will start reducing from 4194 MW at 10:09 hrs to 465 MW at 11:47 hrs with
average ramp down rate of 40MW/Minute and after the maximum eclipse is over, the solar
generation will increase from 468 MW at 11:48 hrs to 4851 MW at 13:51 hrs with average
ramp up rate of 40 MW /Minute .
4194 MW at 10:09 hrs
465 MW at 11:47 hrs
4851 MW at 13:51 hrs
0
1000
2000
3000
4000
5000
6000
05
:46
06
:16
06
:46
07
:16
07
:46
08
:16
08
:46
09
:16
09
:46
10
:16
10
:46
11
:16
11
:46
12
:16
12
:46
13
:16
13
:46
14
:16
14
:46
15
:16
15
:46
16
:16
16
:46
17
:16
17
:46
18
:16
18
:46
19
:16
Sola
r G
ener
atio
n in
MW
Time
Northern Region
Generation during clear sky condition Estimated generation during solar eclipse Difference
4514 MW
Solar eclipse, 21st June 2020 likely impacts and Preparedness- A report Page 23 of 99
The expected maximum solar generation reduction in Rajasthan, Punjab, Uttar Pradesh and
ISTS connected solar plants would be 2180 MW, 479MW, 368 MW and 1612 MW respectively
at the time of maximum obscuration.
Figure 11 shows expected feed-in from solar in Western Region on 21st June 2020 under clear
sky conditions, with and without solar eclipse
Figure 11: Western Region estimated solar generation on 21st June 2020
The states of Gujarat, Maharashtra and Madhya Pradesh in Western Region will observe partial
solar eclipse. Gujarat will observe 80 % of obscuration followed by Madhya Pradesh of 76 %
and then Maharashtra of 60 % obscuration. The estimated reduction of solar generation in
Western Region during solar eclipse is likely to be 2720 MW at time of maximum obscuration
i.e. 11:50 hrs. w.r.t normal day. During the eclipse , solar generation in Western Region will
reduce from 3233 MW at 10:02 hrs to 1249 MW at 11:50 hrs with average ramp down rate of
21 MW/ Minute and after maximum obscuration ,solar generation will start increasing from
1249 MW at11:50 hrs to 3683 MW at 13:58 hrs with average ramp up rate of 22 MW/Minute.
3233 MW at 10:02 hrs
1249 MW at 11:50 hrs
3683 MW at 13:58 hrs
0
500
1000
1500
2000
2500
3000
3500
4000
4500
06
:01
06
:31
07
:01
07
:31
08
:01
08
:31
09
:01
09
:31
10
:01
10
:31
11
:01
11
:31
12
:01
12
:31
13
:01
13
:31
14
:01
14
:31
15
:01
15
:31
16
:01
16
:31
17
:01
17
:31
18
:01
18
:31
19
:01
Sola
r G
ener
atio
n in
MW
Time
Western Region
Generation during clear sky condition Estimated generation during solar eclipse Difference
2720 MW
Solar eclipse, 21st June 2020 likely impacts and Preparedness- A report Page 24 of 99
It is estimated that maximum reduction in solar generation w.r.t. normal day in the states of
Gujarat, Maharashtra and Madhya Pradesh would be 1239 MW at 11:39 hrs, 339 MW at 11:50
hrs and 831 at 11:54 hrs respectively.
The expected total reduction in solar generation from ISTS connected solar plants (Mahindra,
Arisun and ACME) would be 539 MW.
Figure 12 shows expected feed-in from solar in Southern Region on 21st June 2020 under clear
sky conditions, with and without solar eclipse.
Figure 12: Southern Region estimated solar generation on 21st June 2020
Southern part of India will observe partial solar eclipse. As on 31st March 2020, 54 % of all
India’s solar installed capacity is situated in Southern Region. The major solar plants of
Southern Region are located in states of Andhra Pradesh, Karnataka, Tamil Nadu and Telangana
and mean of obscuration at these states are 42%, 43%, 27% and 50% respectively.
It is estimated that reduction in Southern Region solar generation would be 4721 MW at the
time of maximum solar eclipse i.e 11:50 hrs w.r.t. normal day. During the eclipse , the solar
generation in Southern Region is expected to decrease from 10234 MW at 10:09 hrs to 6692
10234 MW at 10:09 hrs
6692 MW at 11:50 hrs
10555 MW at 13:44 hrs
0
2000
4000
6000
8000
10000
12000
14000
05
:46
06
:18
06
:50
07
:22
07
:54
08
:26
08
:58
09
:30
10
:02
10
:34
11
:06
11
:38
12
:10
12
:42
13
:14
13
:46
14
:18
14
:50
15
:22
15
:54
16
:26
16
:58
17
:30
18
:02
18
:34
19
:06
Sola
r G
ener
atio
n i
n M
W
Time
Southern Region
Generation during clear sky condition Estimated generation during solar eclipse Difference
4721 MW
Solar eclipse, 21st June 2020 likely impacts and Preparedness- A report Page 25 of 99
MW at 11:50 hrs with average ramp down rate of 40 MW /Minute and after maximum eclipse ,
solar generation will start increasing from 6692 MW at 11:50 hrs to 10555 MW at 13:44 hrs
with average ramp up rate of 42 MW/Minute.
The expected reduction in solar generation from the state of Andhra Pradesh, Karnataka, Tamil
Nadu and Telangana would be 952 MW,1119 MW, 526 MW and 1147 MW at time of maximum
solar eclipse respectively.
The expected total reduction in solar generation from ISTS connected solar plants (Pavagada
and NP Kunta) would be 1164 MW.
State and ISTS connected solar expected feed-in from solar on 21st June 2020 under clear sky
conditions, with and without solar eclipse is detailed below: -
Figure 13: Rajasthan estimated solar generation on 21st June 2020
1914 MW at 10:09 hrs
139 MW at 11:47 hrs
2290 MW at 13:34 hrs
0
500
1000
1500
2000
2500
05
:46
06
:17
06
:48
07
:19
07
:50
08
:21
08
:52
09
:23
09
:54
10
:25
10
:56
11
:27
11
:58
12
:29
13
:00
13
:31
14
:02
14
:33
15
:04
15
:35
16
:06
16
:37
17
:08
17
:39
18
:10
18
:41
19
:12
Sola
r G
ener
atio
n in
MW
Time
Rajasthan
Generation during clear sky condition Estimated generation during solar eclipse Difference
2180 MW
Solar eclipse, 21st June 2020 likely impacts and Preparedness- A report Page 26 of 99
Figure 14: Punjab estimated solar generation on 21st June 2020
Figure 15: Uttar Pradesh estimated solar generation on 21st June 2020
432 MW at 10:18 hrs
7 MW at 11:58 hrs
472 MW at 13:47 hrs
0
100
200
300
400
500
600
05
:46
06
:16
06
:46
07
:16
07
:46
08
:16
08
:46
09
:16
09
:46
10
:16
10
:46
11
:16
11
:46
12
:16
12
:46
13
:16
13
:46
14
:16
14
:46
15
:16
15
:46
16
:16
16
:46
17
:16
17
:46
18
:16
18
:46
19
:16
Sola
r G
ener
atio
n in
MW
Time
Punjab
Generation during clear sky condition Estimated generation during solar eclipse Difference
479 MW
418 MW at 10:23 hrs
92 MW at 12:08 hrs
421 MW at 13:51 hrs
0
50
100
150
200
250
300
350
400
450
500
05
:46
06
:16
06
:46
07
:16
07
:46
08
:16
08
:46
09
:16
09
:46
10
:16
10
:46
11
:16
11
:46
12
:16
12
:46
13
:16
13
:46
14
:16
14
:46
15
:16
15
:46
16
:16
16
:46
17
:16
17
:46
18
:16
18
:46
19
:16
Sola
r G
ener
atio
n in
MW
Time
Uttar Pradesh
Generation during clear sky condition Estimated generation during solar eclipse Difference
368 MW
Solar eclipse, 21st June 2020 likely impacts and Preparedness- A report Page 27 of 99
Figure 16: Estimated solar generation connected to ISTS in Northern Region
Figure 17: Gujarat estimated solar generation on 21st June 2020
1450 MW at 10:09 hrs
107 MWat 11:47 hrs
1716 MW at 13:34 hrs
0
500
1000
1500
2000
05
:46
06
:17
06
:48
07
:19
07
:50
08
:21
08
:52
09
:23
09
:54
10
:25
10
:56
11
:27
11
:58
12
:29
13
:00
13
:31
14
:02
14
:33
15
:04
15
:35
16
:06
16
:37
17
:08
17
:39
18
:10
18
:41
19
:12
Sola
r G
ener
atio
n in
MW
Time
ISTS Connected Solar Generation in Northern Region
Generation during clear sky condition Estimated generation during solar eclipse Difference
1612 MW
1217 MW at 10:02 hrs
306 MW at 11:39 hrs
1572 MW at 13:27 hrs
0
400
800
1200
1600
2000
05
:46
06
:17
06
:48
07
:19
07
:50
08
:21
08
:52
09
:23
09
:54
10
:25
10
:56
11
:27
11
:58
12
:29
13
:00
13
:31
14
:02
14
:33
15
:04
15
:35
16
:06
16
:37
17
:08
17
:39
18
:10
18
:41
19
:12
Sola
r G
ener
atio
n in
MW
Time
Gujarat
Generation during clear sky condition Estimated generation during solar eclipse Difference
1223 MW
Solar eclipse, 21st June 2020 likely impacts and Preparedness- A report Page 28 of 99
Figure 18: Maharashtra estimated solar generation on 21st June 2020
Figure 19: Madhya Pradesh estimated solar generation on 21st June 2020
443 MW at 10:07 hrs
226 MW at 11:47 MW
607 MW at 13:37 hrs
0
100
200
300
400
500
600
700
05
:46
06
:17
06
:48
07
:19
07
:50
08
:21
08
:52
09
:23
09
:54
10
:25
10
:56
11
:27
11
:58
12
:29
13
:00
13
:31
14
:02
14
:33
15
:04
15
:35
16
:06
16
:37
17
:08
17
:39
18
:10
18
:41
19
:12
Sola
r G
ener
atio
n in
MW
Time
Maharashtra
Generation during clear sky condition Estimated generation during solar eclipse Difference
339 MW
968 MW at 10:12 hrs
262 MW at 11:54 hrs
993 MW at 13:44 hrs
0
200
400
600
800
1000
1200
05
:46
06
:17
06
:48
07
:19
07
:50
08
:21
08
:52
09
:23
09
:54
10
:25
10
:56
11
:27
11
:58
12
:29
13
:00
13
:31
14
:02
14
:33
15
:04
15
:35
16
:06
16
:37
17
:08
17
:39
18
:10
18
:41
19
:12
Sola
r G
ener
atio
n in
MW
Time
Madhya Pradesh
Generation during clear sky condition Estimated generation during solar eclipse Difference
831 MW
Solar eclipse, 21st June 2020 likely impacts and Preparedness- A report Page 29 of 99
Figure 20: Chhattisgarh estimated solar generation on 21st June 2020
Figure 21: Estimated solar generation connected to ISTS in Western Region
24 MW at 10:23 hrs
10 MW at 12:05 hrs
23 MW at 13:56 hrs
0
5
10
15
20
25
30
05
:46
06
:16
06
:46
07
:16
07
:46
08
:16
08
:46
09
:16
09
:46
10
:16
10
:46
11
:16
11
:46
12
:16
12
:46
13
:16
13
:46
14
:16
14
:46
15
:16
15
:46
16
:16
16
:46
17
:16
17
:46
18
:16
18
:46
19
:16
Sola
r G
ener
atio
n in
MW
Time
Chhattisgarh
Generation during clear sky condition Estimated generation during solar eclipse Difference
14 MW
654 MW at 10:26 hrs
180 MW at 12:12 hrs
605 MW at 13:58 hrs
-100
0
100
200
300
400
500
600
700
800
05
:46
06
:17
06
:48
07
:19
07
:50
08
:21
08
:52
09
:23
09
:54
10
:25
10
:56
11
:27
11
:58
12
:29
13
:00
13
:31
14
:02
14
:33
15
:04
15
:35
16
:06
16
:37
17
:08
17
:39
18
:10
18
:41
19
:12
Sola
r G
ener
atio
n in
MW
Time
ISTS Connected Solar Generation in Western Region
Generation during clear sky condition Estimated generation during solar eclipse Difference
539 MW
Solar eclipse, 21st June 2020 likely impacts and Preparedness- A report Page 30 of 99
Figure 22: Andhra Pradesh estimated solar generation on 21st June 2020
Figure 23: Karnataka estimated solar generation on 21st June 2020
1960 MW at 10:15 hrs
1262 MW at 11:56 hrs
2040 MW at 13:39 hrs
0
500
1000
1500
2000
2500
05
:46
06
:17
06
:48
07
:19
07
:50
08
:21
08
:52
09
:23
09
:54
10
:25
10
:56
11
:27
11
:58
12
:29
13
:00
13
:31
14
:02
14
:33
15
:04
15
:35
16
:06
16
:37
17
:08
17
:39
18
:10
18
:41
19
:12
Sola
r G
ener
atio
n in
MW
Time
Andhra Pradesh
Generation during clear sky condition Estimated generation during solar eclipse Difference
952 MW
2250 MW at 10:09 hrs
1424 MW at 11:48 hrs
2346 MW at 13:32 hrs
0
500
1000
1500
2000
2500
3000
05
:46
06
:17
06
:48
07
:19
07
:50
08
:21
08
:52
09
:23
09
:54
10
:25
10
:56
11
:27
11
:58
12
:29
13
:00
13
:31
14
:02
14
:33
15
:04
15
:35
16
:06
16
:37
17
:08
17
:39
18
:10
18
:41
19
:12
Sola
r G
ener
atio
n in
MW
Time
Karnataka
Generation during clear sky condition Estimated generation during solar eclipse Difference
1119 MW
Solar eclipse, 21st June 2020 likely impacts and Preparedness- A report Page 31 of 99
Figure 24: Tamil Nadu estimated solar generation on 21st June 2020
Figure 25: Telangana estimated solar generation on 21st June 2020
1805 at 10:17 hrs
1354 at 11:50 hrs
1900 MW at 13:26 hrs
0
500
1000
1500
2000
2500
05
:46
06
:16
06
:46
07
:16
07
:46
08
:16
08
:46
09
:16
09
:46
10
:16
10
:46
11
:16
11
:46
12
:16
12
:46
13
:16
13
:46
14
:16
14
:46
15
:16
15
:46
16
:16
16
:46
17
:16
17
:46
18
:16
18
:46
19
:16
Sola
r G
ener
atio
n in
MW
Time
Tamil Nadu
Generation during clear sky condition Estimated generation during solar eclipse Difference
526 MW
1799 MW at 10:15 hrs
926 MW at 11:53 hrs
1852 MW at 13:44 hrs
0
500
1000
1500
2000
2500
05
:46
06
:16
06
:46
07
:16
07
:46
08
:16
08
:46
09
:16
09
:46
10
:16
10
:46
11
:16
11
:46
12
:16
12
:46
13
:16
13
:46
14
:16
14
:46
15
:16
15
:46
16
:16
16
:46
17
:16
17
:46
18
:16
18
:46
19
:16
Sola
r G
ener
atio
n in
MW
Time
Telangana
Generation during clear sky condition Estimated generation during solar eclipse Difference
1047 MW
Solar eclipse, 21st June 2020 likely impacts and Preparedness- A report Page 32 of 99
Figure 26: Estimated solar generation connected to ISTS in Southern Region
2578 MW at 10:11 hrs
1703 MW at 11:50 hrs
2598 MW at 11:36 hrs
0
500
1000
1500
2000
2500
3000
3500
05
:46
06
:17
06
:48
07
:19
07
:50
08
:21
08
:52
09
:23
09
:54
10
:25
10
:56
11
:27
11
:58
12
:29
13
:00
13
:31
14
:02
14
:33
15
:04
15
:35
16
:06
16
:37
17
:08
17
:39
18
:10
18
:41
19
:12
Sola
r G
ener
atio
n in
MW
Time
ISTS Connected Solar Generation in Southern Region
Generation during clear sky condition Estimated generation during solar eclipse Difference
1164 MW
Solar eclipse, 21st June 2020 likely impacts and Preparedness- A report Page 33 of 99
Chapter - 5 : Forecasted all India and Regional demand
The pattern of human behavior in India is unique since cultural factors get intertwined with
astronomical events like solar eclipses and lunar eclipses. Majority of the people in India re-
start and undertake a lot of activities as soon as solar eclipse gets over i.e. taking baths, opening
of closed shops, opening of temples, preparation of fresh food which leads to spurt in demand.
India experienced three solar eclipses in the past ten years, first solar eclipse on 22nd July 2009,
followed by 15th January 2010 and then 26th December 2019. During 22nd July event, average
demand reduction in Eastern Region was 4.2% and instantaneous maximum demand reduction
was 7% w.r.t normal day. Eastern Region demand from 21st July 2009 to 23rd July 2009 is given
below: -
Figure 27: Eastern Region demand from 21st July 2009 to 23rd July 2009
The average demand reduction in Southern Region during solar eclipse on 15th January 2010
was 2.5% and instantaneous maximum demand reduction was 5% w.r.t to previous day and
after end of solar eclipse demand increased 3%. Southern Region demand from 14th January
2010 to 16th January 2010 is given below: -
8500
8700
8900
9100
9300
9500
9700
9900
10100
10300
4:0
0:0
0
4:1
5:0
0
4:3
0:0
0
4:4
5:0
0
5:0
0:0
0
5:1
5:0
0
5:3
0:0
0
5:4
5:0
0
6:0
0:0
0
6:1
5:0
0
6:3
0:0
0
6:4
5:0
0
7:0
0:0
0
7:1
5:0
0
7:3
0:0
0
7:4
5:0
0
8:0
0:0
0
8:1
5:0
0
8:3
0:0
0
8:4
5:0
0
9:0
0:0
0
Dem
and
in M
W
Time
Eastern Region Demand
21-07-2009 22-07-2009 23-07-2009
Solar eclipse, 21st June 2020 likely impacts and Preparedness- A report Page 34 of 99
Figure 28: Southern Region demand from 14th January 2010 to 16th January 2010
In third annular solar eclipse which was on 26th December 2019, the pattern of demand
variance showed that on an average around 2.4% demand reduced with an instantaneous
maximum demand reduction of 4.2 %. Further, it was observed that all India demand increased
by about 6372 MW i.e. by 3.8 %, when eclipse got over. All India demand from 24th December
2019 to 26th December 2019 is given below: -
Figure 29: All India demand from 24th December 2019 to 26th December 2019
18000
20000
22000
24000
260000
:01
:00
0:5
5:0
0
1:5
0:0
0
2:4
5:0
0
3:4
0:0
0
4:3
5:0
0
5:3
0:0
0
6:2
5:0
0
7:2
0:0
0
8:1
5:0
0
9:1
0:0
0
10
:05
:00
11
:00
:00
11
:55
:00
12
:50
:00
13
:45
:00
14
:40
:00
15
:35
:00
16
:30
:00
17
:25
:00
18
:20
:00
19
:15
:00
20
:10
:00
21
:05
:00
22
:00
:00
22
:55
:00
23
:50
:00
Dem
and
in M
W
Time
Southern Region Demand14-01-2010 15-01-2010 16-01-2010
Average Demand Reduction: 2.5 % Instantaneous maximum reduction in
demand : 5 %
130000
135000
140000
145000
150000
155000
160000
165000
170000
175000
06
:00
06
:20
06
:40
07
:00
07
:20
07
:40
08
:00
08
:20
08
:40
09
:00
09
:20
09
:40
10
:00
10
:20
10
:40
11
:00
11
:20
11
:40
12
:00
12
:20
12
:40
13
:00
Dem
and
in M
W
Time
All India Demand 26.12.2019 25.12.2019 24.12.2019
Solar eclipse, 21st June 2020 likely impacts and Preparedness- A report Page 35 of 99
It may be noted that due to announcement of countrywide lockdown due to COVID-19 since
25th March 2020, All India demand reduced by 40-45 GW in the months of March & April 2020.
However, at the time of writing this report lockdown has been relaxed to some extent and
commercial & industrial activities have started leading to increase in demand. If similar
situation prevails in the month of June 2020, then it is expected that all India demand is likely
to be in the range of ~150-155 GW during solar eclipse period on 21st June 2020.
Based on previous solar eclipse events occurrences in India, it is expected that during eclipse
on 21st June 2020, there would be depression in demand due to human behaviour. However,
due to countrywide lockdown, this time reduction and increase in demand could be less
compared to previous eclipses because temples, malls and small commercial shops are already
closed and heating load will not be there in Southern Region. Therefore, slowing down human
activity in terms of cooking, agriculture and other day to day activities would lead to decrease
and increase in power consumption.
In view of the above, it is expected that all India average demand may reduce by 2-2.5% with
instantaneous maximum reduction 3-3.5 % and after eclipse it may increase by the same
amount.
The estimated all India and region wise demand for 21st June 2020 is given below: -
Figure 30: All India estimated demand on 21st June 2020
115000
125000
135000
145000
155000
165000
175000
00
:55
01
:55
02
:55
03
:55
04
:55
05
:55
06
:55
07
:55
08
:55
09
:55
10
:55
11
:55
12
:55
13
:55
14
:55
15
:55
16
:55
17
:55
18
:55
19
:55
20
:55
21
:55
22
:55
Dem
and
in M
W
Time
All India Demand
2018 2019 2020(Forecasted)
Solar eclipse, 21st June 2020 likely impacts and Preparedness- A report Page 36 of 99
Figure 31: Northern Region estimated demand on 21st June 2020
Figure 32: Western Region estimated demand on 21st June 2020
35000
40000
45000
50000
55000
60000
650000
0:5
0
01
:45
02
:40
03
:35
04
:30
05
:25
06
:20
07
:15
08
:10
09
:05
10
:00
10
:55
11
:50
12
:45
13
:40
14
:35
15
:30
16
:25
17
:20
18
:15
19
:10
20
:05
21
:00
21
:55
22
:50
23
:45
Dem
and
in M
W
Time
Northern Region Demand
2018 2019 2020(Forecasted)
30000
35000
40000
45000
50000
00
:50
01
:45
02
:40
03
:35
04
:30
05
:25
06
:20
07
:15
08
:10
09
:05
10
:00
10
:55
11
:50
12
:45
13
:40
14
:35
15
:30
16
:25
17
:20
18
:15
19
:10
20
:05
21
:00
21
:55
22
:50
23
:45
Dem
and
in M
W
Time
Western Region Demand
2018 2019 2020(Forecasted)
Solar eclipse, 21st June 2020 likely impacts and Preparedness- A report Page 37 of 99
Figure 33: Southern Region estimated demand on 21st June 2020
Figure 34: Eastern Region estimated demand on 21st June 2020
19000
24000
29000
34000
39000
44000
00
:00
00
:55
01
:50
02
:45
03
:40
04
:35
05
:30
06
:25
07
:20
08
:15
09
:10
10
:05
11
:00
11
:55
12
:50
13
:45
14
:40
15
:35
16
:30
17
:25
18
:20
19
:15
20
:10
21
:05
22
:00
22
:55
23
:50
Dem
and
in M
W
Time
Southern Region Demand
2018 2019 2020(Forecasted)
9000
11000
13000
15000
17000
19000
21000
23000
25000
00
:50
01
:45
02
:40
03
:35
04
:30
05
:25
06
:20
07
:15
08
:10
09
:05
10
:00
10
:55
11
:50
12
:45
13
:40
14
:35
15
:30
16
:25
17
:20
18
:15
19
:10
20
:05
21
:00
21
:55
22
:50
23
:45
Dem
and
in M
W
Time
Eastern Region Demand
2018 2019 2020(Forecasted)
Solar eclipse, 21st June 2020 likely impacts and Preparedness- A report Page 38 of 99
Figure 35 : North Eastern Region estimated demand on 21st June 2020
700
900
1100
1300
1500
1700
1900
2100
2300
2500
27000
0:4
00
1:2
50
2:1
00
2:5
50
3:4
00
4:2
50
5:1
00
5:5
50
6:4
00
7:2
50
8:1
00
8:5
50
9:4
01
0:2
51
1:1
01
1:5
51
2:4
01
3:2
51
4:1
01
4:5
51
5:4
01
6:2
51
7:1
01
7:5
51
8:4
01
9:2
52
0:1
02
0:5
52
1:4
02
2:2
52
3:1
0
De
ma
nd
in
MW
Time
North Eastern Region Demand
2018 2019 2020(Forecasted)
Solar eclipse, 21st June 2020 likely impacts and Preparedness- A report Page 39 of 99
Chapter - 6 : System reliability study for 21st June 2020 solar eclipse
As per the forecast, it is estimated that the solar eclipse would lead to reduction in all India solar
generation from 17315MW at 10:02 hrs to 8415 MW at 11:50 hrs. Subsequently, the generation
will start increasing achieving normal pattern by 13:58 hrs. The average ramp down and ramp
uprate is expected to be 102MW/Minute and 104 MW/Minute respectively. Region wise details
are as under: -
S. No.
Region
Forecasted Solar Generation on 21st June
(MW) Difference
(MW) Difference
(MW)
Forecasted solar
generation at 11:50 hrs in case
of clear sky (D)
Difference (MW)
10:02 hrs
11:50 hrs
13:58 hrs (B-A) (C-B) (D-B)
(A) (B) (C)
1 Northern 4076 474 4834 -3602 4360 4977 4503
2 Western 3233 1249 3685 -1984 2436 3968 2719
3 Southern 10006 6692 10260 -3314 3568 11413 4721
4 All India 17315 8415 18779 -8900 10364 20358 11943
Table 4: All India and Region wise estimated solar generation
The solar generation in above mentioned regions will have to be replaced with conventional
generation and this may affect the normal inter-regional flow pattern. The inter-regional drawls
on 23rd June 2019 (Sunday during the eclipse week last year) given below provide an idea of
the margin that will be available on inter-regional corridors on 21st June 2020.
S.
No.
Exporting
Region
Importing
Region
Present
ATC
IR -
23rd
June
2019
10:00
hrs
Margin
IR -
23rd
June
2019
11:50
hrs
Margin
IR -
23rd
June
2019
(Max)
Margin
1 Western Northern 17200 6092 11108 7269 9931 9977 7223
2 Eastern Northern 5250 3109 2141 2970 2280 3642 1608
3 Western Southern 6950 1393 5557 420 6530 2635 4315
4 Eastern Southern 5950 2467 3483 2123 3827 1525 4425
5 Import of NR 22450 9632* 12818 10739* 11711 13983* 8467
6 Import of SR 12900 3760 9140 2543 10357 4800 8100 *includes 500 MW from NER
Table 5: Inter-regional drawls and margin on 23rd June 2019
Solar eclipse, 21st June 2020 likely impacts and Preparedness- A report Page 40 of 99
Based on the margins available in inter-regional corridor on 23rd June 2019, the solar
generation reduction of ~4.5 GW is in NR, ~2.7 GW in WR and ~4.7 GW in SR on 21st June 2020
is not expected to cause any constraints in inter-regional corridors.
A power system simulation study has been carried out to analyze the impact of eclipse on
network loadings and voltages. The details are given below.
Assumptions: -
a) All India June 2020 case with updated network and scaled load and generation for 10:00
hrs and 11:50 hrs of 21st June 2020 has been considered for study purpose.
b) The all India demand has been considerably less than the usual demand during the last
02 months due to the countrywide lockdown since 25th March 2020. However, with
gradual relaxation of restrictions during the last few days, the demand has started
picking up.
The demand of following 02 days has been considered to estimate the demand on 21st
June at 10:00 hrs.
• 17th May 2020 – Previous Sunday
• 23rd June 2019 – Sunday during the eclipse week last year
The region-wise demand considered in power system simulation case is given below. The state
wise LGB in the case is at Annexure-IV.
S. No. Region Demand 21st June Demand in Power System Simulation cases
17th May 2020 23rd June 2019 10:00 hrs 11:50 hrs*
1 Northern 42597 51776 50316 51316
2 Western 40618 44565 43865 44865
3 Southern 37294 35897 36603 37103
4 Eastern 15298 16404 16604 17104
5 North Eastern 1542 1819 1710 1710
6 All India 137349 150461 149101 152100
• All figures are in MW for 10:00 hrs
*Usually, 3 GW increase in all India demand is observed between 10:00 hrs to 12:00 hrs.
Table 6: Region wise considered demand in power system simulation study case
Solar eclipse, 21st June 2020 likely impacts and Preparedness- A report Page 41 of 99
c) The state and plant wise solar generation considered in the case (10:00 hrs and 11:50
hrs) is enclosed at Annexure-V.
d) The increase in source wise generation from 10:00 hrs to 11:50 hrs (as replacement of
solar generation) is enclosed at Annexure-VI.
Study Results: -
a) Comparison of Inter-regional flows
S. No.
Exporting Region
Importing Region
Present ATC
Base Case
Margin
Eclipse Case
Margin 10:00
hrs 11:50
hrs
1 Western Northern 17200 7200 10000 5790 11410
2 Eastern Northern 5250 1513 3737 1699 3551
3 Western Southern 6950 1452 5498 2138 4812
4 Eastern Southern 5950 3960 1990 4246 1704
5 Western Eastern - 2387 - 1721 -
6 Import of NR 22450 9213* 13237 7989* 14461
7 Import of SR 12900 5412 7488 6384 6516
All figures are in MW *includes 500 MW from NER
Table 7: Inter-regional flow in base case and eclipse case
b) Maximum and minimum voltages at 400 kV level and above observed in the eclipse case
are enclosed at Annexure-VII.
c) Network loadings are observed to be within limits. Except 765 kV Sasan – Vindhyachal
D/C, loading of all 765 kV lines are below 50% of SIL. Further, at 400 kV level, loading of
no major line is observed to be beyond 50% of thermal limit.
d) Following ICTs have been observed as N-1 non-compliant in the eclipse case.
• 2X500 MVA 400/220 kV ICTs at Rajpura (loading 76%)
• 2X500 MVA 400/220 kV ICTs at Deepalpur (loading 66%)
Solar eclipse, 21st June 2020 likely impacts and Preparedness- A report Page 42 of 99
e) Voltages at buses near large solar parks are as under: -
S. No.
Station Voltage
Level (kV)
Voltage (kV)
Voltage (kV) Fault Level
Base Case 10:00 hrs
Eclipse Case11:50 hrs
1 Bhadla - PG 400 401 408 18100 MVA,
26.1 KA
2 Bhadla-RS 400 401 407 17046 MVA,
24.6 KA
3 Rewa-PG 400 403 406 8524 MVA, 12.3
KA
4 NP Kunta 400 419 418 18140 MVA,
26.1 KA
5 Pavagada 400 414 415 29574 MVA,
42.6 KA
6 Bhadla-PG 765 781 782 19139 MVA,
14.4 KA
7 Bikaner-PG 765 777 786 28026 MVA,
21.1 KA
Table 8: Voltages at buses near large solar parks
f) Actions to be taken: -
• Suitable Margins in HVDCs towards NR and SR may be kept before start of eclipse and
power order may be modulated proactively. Power order to be maximized during
reduction in solar generation and to be reduced as per requirement while increase in
solar generation.
• SCED to be disabled before the eclipse to keep sufficient margins in inter-regional
corridors and ISGS plants.
• All the bus reactors near solar generating stations to be switched on gradually before
the start of the eclipse and to be taken out as per grid voltage after 12:00 hrs.
• Solar generating plants/inverters may be advised to generate/absorb VARs to maintain
the voltage within permissible limits.
• All other generating stations may also be advised to generate/absorb VARs as per
capability curve.
• STATCOMs, SVCs to be in service in voltage control mode (reference 1 pu).
• Sufficient reserves to be maintained and maximum units to be brought on bar before the
eclipse.
Solar eclipse, 21st June 2020 likely impacts and Preparedness- A report Page 43 of 99
Chapter - 7 : Operational Planning
7.1 Northern Region
It is estimated that solar generation reduction in Northern Region is likely to be 4514 MW at
the time of maximum obscuration w.r.t. normal day. During the eclipse, solar generation in
Northern Region will start reducing from 4194 MW at 10:09 hrs to 465 MW at 11:47 hrs with
average ramp down rate of 40 MW/Minute and after the maximum eclipse is over the solar
generation will increase from 468 MW at 11:48 hrs to 4851 MW at 13:51 hrs with average
ramp rate of 40 MW/Minute .
The Northern Region is required to manage the following during eclipse period
1. Managing solar generation reduction & associated ramps from eclipse start to maximum
eclipse time.
2. Managing solar generation increase & associated ramps from maximum eclipse to end
of eclipse.
3. Arranging power from alternate sources for meeting the demand which was generally
met from solar power
The management of anticipated solar reduction and subsequent recovery required high
ramping resources with flexible characteristics. The high ramping resources such as hydro and
gas generators are required to be scheduled during the event.
I. Scheduling of all conventional reserves in Northern Region
The data of reserves available during 20th June-19 to 22nd June-19 in NR ISGS thermal stations
have been analysed and average cold and hot reserves available are shown below: -
Figure 36: Northern Region average cold and hot reserve
Solar eclipse, 21st June 2020 likely impacts and Preparedness- A report Page 44 of 99
It is observed from the above plot that average cold reserve and hot reserve were 2162 MW
and 860 MW between 10:00 hrs to 14:00 hrs (while calculating the reserves SCED is ignored).
It is expected that on 21st June 2020, ISGS generators to the tune of 3000-3500 MW would be
under reserve shutdown. Due to less demand in Northern Region, at present Dadri TPS-I, Dadri
TPS-II, Unchahar TPS and ISTPP Jhajjar of NR ISGS thermal units are under reserve shutdown.
Based on the reserve availability before 21st June 2020 bringing of one or two units of coal-
based NR ISGS thermal generators may be considered.
During the period of 20th June 19 to 22nd June19, Gas power plant at Auraiya GPS and Anta GPS
were also under reserve shutdown due to less demand. Following gas based units are likely to
be available on 21st June 2020 for scheduling.
S.NO. STATION EFFECTIVE INSTALLED CAPACITY (MW)
1 DADRI GPS 2X154.51+4x130.19 = 830.00
2 ANTA GPS 2X153.21+3x88.71 = 419.00
3 AURAIYA GPS 2X109.3+4x111.19 = 663.00
TOTAL 1912.00
Table 9: Northern Region ISGS gas based stations
5-minute scheduling from gas-based stations has been done in line with solar generation
reduction during solar eclipse. The maximum 1227 MW has been scheduled from gas based
stations during maximum solar eclipse.
Figure 37: Northern Region gas generation schedule on 21st June 2020
0
200
400
600
800
1000
1200
1400
0
1000
2000
3000
4000
5000
6000
10
:15
10
:25
10
:35
10
:45
10
:55
11
:05
11
:15
11
:25
11
:35
11
:45
11
:55
12
:05
12
:15
12
:25
12
:35
12
:45
12
:55
13
:05
13
:15
13
:25
13
:35
13
:45
Gas
Sch
ed
ule
in M
W
Sola
r G
ener
atio
n in
MW
Time
Northern Region Gas Generation scheduleGeneration during clear sky condition Estimated generation during solar eclipse
Total Schedule of Gas Generation
Solar eclipse, 21st June 2020 likely impacts and Preparedness- A report Page 45 of 99
Gas based stations scheduling is done considering open cycle mode of operation. However, on
real time basis based on machines on-Bar in close cycle or open cycle same may be rescheduled.
Plant wise 5-minute schedule for gas-based station is attached at Annexure- VIII
II. Scheduling of Hydro Generation in Northern Region
During the eclipse period, hydro generators may be scheduled to tackle solar generation ramp
down and ramp up. As per figure 38 shown, it is observed that Northern Region total reservoir
level (Energy Content) in MU as on 20th May 2020 is 1279 MU, which is similar to last year’s
reservoir level.
Figure 38: Energy Content (MU) on last day of the month for the years 2018-19 to 2020-21
Hydro stations scheduling has been done based on inflow patterns and dam level for the year
2018 and 2019.Hydro stations having significant margin (Tehri, Koldam, Chamera-I&III,
Dhauliganga, Pong, Parbati-III, 2 machines each in Bhakhra-L&R) have been considered for
optimization. The details of hydro plant are given below: -
0
500
1000
1500
2000
2500
3000
3500
4000
4500
30
th A
pri
l
31
st M
ay
30
th J
un
e
31
st J
uly
31
st A
ug
30
th S
ept
31
st O
ct
30
th N
ov
31
st D
ec
31
st J
an
28
th F
eb
31
st M
arch
Ener
gy C
on
ten
t in
MU
Last day of the month
Reservior levels in MU as on last day of the month for the years 2018-19 to 2020-21
2018-19 2019-20 2020-21 10 Years Average
Solar eclipse, 21st June 2020 likely impacts and Preparedness- A report Page 46 of 99
S.NO. STATION EFFECTIVE INSTALLED CAPACITY (MW)
1 TEHRI HPS 4x250 = 1000.00
2 KOLDAM HPS 4x200 = 800.00
3 CHAMERA-I HPS 3x180 = 540.00
4 CHAMERA-III HPS 3x77 = 231.00
5 DHAULIGANGA HPS 4x70 = 280.00
6 PARBATI-III HPS 4x130 = 520.00
7 BHAKHRA-L&R HPS 2x108+3x126+5x157 = 1379.00
8 PONG HPS 6x66 = 396.00
TOTAL 5146.00
Table 10: Northern Region ISGS hydro generating stations
Spillage is anticipated in Major RoR and RoR with pondage plants like NJHEP, Rampur,
Dhulhasti, KWHEP, Salal, Uri-I&II, so these are not considered for optimization.
During start of solar eclipse hydro generation is required to ramp up and subsequently after
maximum solar eclipse, hydro generation needs to be ramped down. The figure 39 shows 5-
minute hydro schedule in line with solar generation reduction. Plant wise 5-minute hydro
scheduling is attached as per Annexure-IX
Figure 39: Northern Region hydro generation schedule on 21st June 2020
0
500
1000
1500
2000
2500
3000
3500
4000
0
1000
2000
3000
4000
5000
6000
10
:15
10
:25
10
:35
10
:45
10
:55
11
:05
11
:15
11
:25
11
:35
11
:45
11
:55
12
:05
12
:15
12
:25
12
:35
12
:45
12
:55
13
:05
13
:15
13
:25
13
:35
13
:45
Hyd
ro S
che
du
le in
MW
Sola
r G
ener
atio
n in
MW
Time
Northern Region Hydro Generation ScheduleGeneration during clear sky condition Estimated generation during solar eclipse
Total Hydro Schedule
Solar eclipse, 21st June 2020 likely impacts and Preparedness- A report Page 47 of 99
Following actions are also required to be taken during scheduling of hydro and gas-based
stations
I. All Hydro stations may be advised to operate in FGMO. Further Droop settings of all
hydro stations and gas stations may be reduced to 2-3%. Similarly drop of thermal
stations may also be reduced to 3-4%.
II. Constituents may be requested to freeze their requisitions well in advance say by 09:00
hrs on 21st June 2020 to enable better reserve assessment and RRAS planning by
NRLDC/NLDC in advance.
III. In addition to above, all Gas based stations and some hydro stations will be kept on
minimum load up to around 13:50 hrs on the day of eclipse to enable fast ramping in
case sudden load rise post solar eclipse.
Rajasthan
The expected maximum solar generation reduction in Rajasthan would be 2180 MW during the
eclipse period. Rajasthan has to arrange this power from their available resource. At the peak
of eclipse, all hydro generation may be maximized so that maximum fast ramping hydro
generation would be available for managing solar generation increase after eclipse. The
generation from wind plants should also be properly forecasted and closely monitored during
eclipse period. Rajasthan has following hydro plants that may be scheduled during solar eclipse
period from their available resource to mitigate this effect.
S.NO. STATION EFFECTIVE INSTALLED CAPACITY (MW)
1 MAHI BAJAJ SAGAR 2x25+2x45 = 140.00
2 RANA PRATAP SAGAR 4x43 = 172.00
TOTAL
312.00
Table 11: Rajasthan hydro generating stations
Thermal generation of Rajasthan also needs to be planned in coordination with hydro
generation so that additional support from thermal can be utilized. ISGS Hydro plants may also
be scheduled to further optimize the drawal from the grid.
Solar eclipse, 21st June 2020 likely impacts and Preparedness- A report Page 48 of 99
Uttar Pradesh
The expected maximum solar generation reduction in Uttar Pradesh would be 368 MW during
solar eclipse period. Uttar Pradesh has to arrange this power from their available resource. The
list of available Hydro resource from Uttar Pradesh is given below: -
S.NO. STATION EFFECTIVE INSTALLED CAPACITY (MW)
1 RIHAND HPS 6x50 = 300.00
2 OBRA HPS 3x33 = 99.00
3 MATATILA HPS 3x11 = 33.00
4 VISHNUPRAYAG HPS 4x110 = 440.00
5 ALAKNANDA HPS 4x82.50 = 330.00
TOTAL 1202.00
Table 12: Uttar Pradesh hydro generating stations
Uttar Pradesh has to schedule 368 MW power with above available hydro resources. If the
above resource is not available on day of eclipse, then 368 MW will be required to be scheduled
from ISGS hydro plant /thermal /gas or own thermal generations during the eclipse period.
Punjab
The expected maximum solar reduction during solar eclipse period in Punjab would be 479
MW. Punjab has to arrange this power from their available resource. The list of available hydro
resource of Punjab is given below. Punjab is required to schedule 479 MW power from available
hydro resources and if on day of eclipse these resources are not available then same quantum
may be scheduled from ISGS hydro plants.
S.NO. STATION EFFECTIVE INSTALLED CAPACITY (MW)
1 SHANAN HPS 4x15+1x50 = 110.00
2 RANJIT SAGAR HPS 4x150 = 600.00
TOTAL
710.00
Table 13: Punjab hydro generating stations
Solar eclipse, 21st June 2020 likely impacts and Preparedness- A report Page 49 of 99
7.2 Western Region
Based on the obscuration factor, provisional forecast of the solar generation with the eclipse
impact has been calculated. Details of maximum % of obscuration and estimated reduction of
solar generation in Western Region on 21st June 2020 are given below: -
State/Region Maximum% of Obscuration Estimated Maximum
Solar Generation
Reduction (MW)
Gujarat 80% 1223
Madhya Pradesh 76% 831
Maharashtra 60% 359
Western Region 68% 2720
Following operations may be planned to balance the load and generation to maintain the
compliance in the grid during solar eclipse.
I. Scheduling of all conventional generation in Western Region As per forecast of solar generation during solar eclipse, maximum reserved required is 2720
MW the same is plotted and shown below: -
Figure 40: Western Region reserve requirement on 21st June 2020
Maximum reserve required is 2720MW. The data of reserves available during 18-June -19 to
25-June-2019 in WR ISGS station is analysed and average reserves available is shown below: -
Solar eclipse, 21st June 2020 likely impacts and Preparedness- A report Page 50 of 99
Actual average on-bar reserves available during 10:00 hrs to 14:00 hrs was in the range of
1000MW in ISGS units at regional level. Lower reserve was available due to outage of Gas units
at KAWAS and Gandhar under RSD (less schedule). Also, during June’19, It was also observed
that Gadarwara(800MW) and Solapur(660MW) were kept out on RSD. Therefore, to mitigate
the requirement of reserves of 2720 MW, planning of generating units to be kept on bar for
flexibility. Appropriate planning to keep the units (listed below) in service may be done keeping
the fast response required during the eclipse.
S.NO. STATION EFFECTIVE INSTALLED CAPACITY (MW)
1 KAWAS GPS 4x106+2x116.1 = 656.20
2 GANDHAR GPS 3x144.3+1x224.49 = 657.39
3 MAUDA-I &II 2x500+2x660 = 540.00
4 GADARWARA 1x800 = 800.00
5 KHARGONE 2x660 = 1320.00
6 SOLAPUR 2x660 = 1320.00
7 LARA 2x800 = 1600.00
TOTAL 6893.59
Table 15: Western Region ISGS Gas and Thermal stations
Time Western Region
Schedule (MW) on Bar DC (MW) Reserves Available (MW) 10:00 16263 17240 977 10:15 16300 17324 1024 10:30 16320 17331 1011 10:45 16353 17361 1008 11:00 16388 17375 987 11:15 16399 17346 947 11:30 16381 17353 972 11:45 16302 17280 978 12:00 16274 17306 1032 12:15 16296 17309 1012 12:30 16266 17296 1030 12:45 16215 17230 1015 13:00 16150 17232 1083 13:15 16124 17164 1040 13:30 16211 17164 954 13:45 16282 17177 895 14:00 16267 17176 909
Table 14: Average available reserves in WR ISGS stations on 18th June 19 to 25th June 19
Solar eclipse, 21st June 2020 likely impacts and Preparedness- A report Page 51 of 99
Schedule requisition may be given by the state after planning at the ISGS plants. Gujarat has
high impact on solar generation therefore, Gujarat may plan their Gas plant to keep on bar for
real time operation during solar eclipse. Few units in Gujarat like Wanakbori, GIPCL,
Gandhinagar, GPPC,GSEG etc. were kept out on RSD/No schedule during June 2019 at Gujarat.
These units may be planned for mitigation the impact of solar eclipse in Gujarat.
II. Scheduling of Hydro Generation in Western Region
The Scheduling of Hydro plant during solar eclipse may be given the priority by the state as the
response of hydro generation is very fast compared to other type of generation.
Ghatghar(Maharashtra) is the only Pump storage plant in Western region. It has generated
during peak demand and pumped during off peak hours in the month of June 2019.
Maharashtra may plan the two units at Ghatghar(2x125MW) each to give the response during
solar eclipse 2019. Apart from Ghatghar Pump Storage Plant, Following is the list of Hydro
generators in WR having reservoir level above Minimum Draw Down Level (MDDL). Plots of
generation and reservoir level is enclosed as per Annexure X.
S.NO. Hydro Generator EFFECTIVE INSTALLED
CAPACITY (MW)
State
Owned/ISGS
Reservoir
level above
Minimum
Drawdown
Level(MDDL)
1 SARDAR SAROVAR HPS 6x200+5x50 =1450.00 ISGS Yes
2 KOYNA HPS 4x70+4x80+4x80+4x250
=1920.00 Maharashtra Yes
3 UKAI HPS 4x75+2x2.5 =305.00 Gujarat Yes
4 KANDANA HPS 4x60 =240.00 Gujarat Yes
5 INDIRASAGAR HPS 8x125 =1000.00 MP Yes
6 OMKARESHWAR HPS 8x65 =520.00 MP Yes
7 TONS HPS 3x105 = 315.00 MP Yes
8 PRNCH HPS 2x80 =160.00 MP Yes
9 GANDHISAGAR HPS (5x23) x50% =57.50 MP Yes
TOTAL 5967.50
Table 16: Western Region ISGS and state hydro generating stations
Solar eclipse, 21st June 2020 likely impacts and Preparedness- A report Page 52 of 99
Therefore, each state of Western Region may plan their hydro generation during solar eclipse so
that immediate response can be given during sudden drop and increase in the solar generation
in each state. Hydro generation may also be utilized for balancing the frequency during real time
operation.
III. Action required by state
Following actions required from the states for mitigation from the impact of solar eclipse-
i. Estimation of total solar power reduction may be done in addition to the forecast shared
by POSOCO considering the short-range weather data. The same may be revised during
the day.
ii. Load forecast shall be prepared by the state incorporating the impact of solar eclipse
and same shall be shared with WRLDC.
iii. Study the potential effect of solar eclipse on respective control areas. Study may be
carried out in each state for potential loading of transmission corridors and voltage
impact due to solar eclipse.
iv. Proper planning of the reserves as per requirement may be done for managing the
reduced solar generation and load.
v. Ramping may be planned properly to avoid the frequency fluctuations during real time
operation.
vi. All the reactors shall be kept in service to balance the voltage and reactive power
support may be given by the state thermal generators.
vii. Coordination requirement between RLDCs, SLDCs and RE plants.
viii. Collection of contact details of solar plants having capacity of more than 50 MW and
availability of Power Plant Control (PPC) facility.
ix. Operational planning within the state shall be prepared and communicated to the state
entities for action required from conventional plants. Operational plan issued by the
states may be shared with WRLDC 3 days before the solar eclipse.
x. Post Event, the data of actual solar radiation and actual solar generation may be collected
from large solar plants in the state and may be shared with WRLDC.
States may study the impact of solar eclipse on weak ahead/day ahead/intraday basis. The
same may be intimated to the forecasters from which states are taking forecast services.
Weather Forecast (Solar Radiation) also may be asked from the weather service provider in
state so that post event study can be carried out and it may be used in the future. Based on the
Solar eclipse, 21st June 2020 likely impacts and Preparedness- A report Page 53 of 99
forecast, state may plan their schedule in Hydro generators as well as in thermal plants.
Locations may be identified where voltage balancing is required in the state during solar
eclipse. Solar generating stations having PPC may be utilized for voltage balancing. Also, the
switching of Reactors may be planned to control the voltage at nearby substations.
IV. Solar plants to be selected for post event analysis
At regional level, Solar Plant e.g. Mahindra, ACME and Arinsun will be selected for forecasting
of the generation. The Post event analysis will also be carried out after the solar eclipse. Solar
radiation forecast considering the solar eclipse impact shall be requested by the Weather
Service provider in REMC. There will be four forecasts available by FSP (Forecast Service
Providers) in REMC to take the decision in real time. Also post event, the comparison of forecast
and actual impact of solar eclipse shall be carried out.
Similarly, all the states may plan to select the large solar park in the state to study, forecast and
post event analysis.
Solar eclipse, 21st June 2020 likely impacts and Preparedness- A report Page 54 of 99
7.3 Southern Region
I. Expected demand
Southern Region demand is expected to be in the range of 840-860 MU on 21st June due to
COVID-19 and weekend. As observed from previous eclipse SR demand will be less during
eclipse period and after end of the eclipse there will be sudden rise in the demand. Considering
these factors estimated SR Demand for 21st June 2020 is expected as below: -
Figure 41: Southern Region estimated demand on 21st June 2020
II. Solar eclipse expected impact on Southern Region solar generation
As per predictions by weather agencies southwest monsoon enters India by 1st June and hence
the probability of sky being clear at solar park locations of Southern Region on 21st June 2020
is less. However, impact assessment is done by assuming clear sky conditions which is the worst
possible scenario.
Expected solar reduction is 3542 MW from 10234 MW at 10:09 hrs to 6692 MW at 11:50 Hrs.
reduction in SR solar generation at eclipse peak is 4721 MW at 11:50 hrs. After peak of eclipse
generation will rise from 6692 MW to 10555 MW, total of 4130 MW rise in 1 hour and 39
minutes.
Solar eclipse, 21st June 2020 likely impacts and Preparedness- A report Page 55 of 99
III. Reservoir position
Southern region total reservoir level (Energy Content) as on 17th May 2020 is 4520 MU, which
is 1300MU more compared to last reservoir level of 3238 MU.
Figure 42: SR Energy Content as on last day of the month for the years 2018-19 to 2020-21
Day wise maximum hydro generation of Southern region for May 2019, June 2019 and
May 2020 up to 17th May 2020:
Figure 43: Day wise Southern Region hydro generation for June-19 and May 2020
Solar eclipse, 21st June 2020 likely impacts and Preparedness- A report Page 56 of 99
Maximum hydro generation in Southern Region during May 2019 is in the range of 3500- 5000
MW, during June 2019 is in the range of 3000-4500 MW and during May 2020 is in the range of
4500 -5000 MW. With the existing reservoir levels, it is expected that 3300-3700 MW flexibility
can be achieved from Hydro generation.
IV. Reserves in ISGS Thermal generators
Reserves available in Southern Region ISGS thermal generator for the period of 9:00 hrs to
15:00 hrs during 17th to 22nd June 2019 period given below: -
Table 17: Average reserve available in Southern Region ISGS stations on 17th to 22nd June19
Average reserve in ISGS thermal generators during eclipse period is in the range of 2500 -3000
MW with minimum reserve of around 1000 MW during eclipse period (10:00 hrs to 14:00 hrs)
for all the days during the above week except for 21-06-2019. June 21st 2020 is Sunday and it
fall in high wind season of Southern Region there will be sufficient reserves in ISGS generators.
It is expected that ISGS generators to the tune of 5000 – 6000 MW will be under reserved
shutdown. Based on the reserve availability pattern for 18th & 19th June 2020 bringing one or
two ISGS units can be considered.
BlockTime
Period
Average
Reserve in MW
Maximum
Reserve in MW
Minimum
Reserve in MW
37 09:00-09:15 2645 3839 892
38 09:15-09:30 2536 3942 553
39 09:30-09:45 2633 3762 374
40 09:45-10:00 2833 3517 1739
41 10:00-10:15 2578 3257 1718
42 10:15-10:30 2639 3419 1617
43 10:30-10:45 2795 4418 1351
44 10:45-11:00 2618 4338 361
45 11:00-11:15 2628 4049 634
46 11:15-11:30 2623 4114 1159
47 11:30-11:45 2983 4733 1286
48 11:45-12:00 2911 3957 1267
49 12:00-12:15 2962 3931 1131
50 12:15-12:30 3013 3986 1116
51 12:30-12:45 3327 4366 1636
52 12:45-13:00 3125 4107 1545
53 13:00-13:15 3078 4334 1697
54 13:15-13:30 3051 4100 1450
55 13:30-13:45 2744 3881 1543
56 13:45-14:00 2682 3585 1233
57 14:00-14:15 2432 3794 579
58 14:15-14:30 2322 3506 533
59 14:30-14:45 1983 2812 199
60 14:45-15:00 1680 2498 303
Solar eclipse, 21st June 2020 likely impacts and Preparedness- A report Page 57 of 99
V. Expected solar generation variation state wise and management plan
System operator needs to plan for the management of following three things as illustrated with
the below diagram
Figure 44: Southern Region estimated solar generation on 21st June 2020
1. Managing Solar generation reduction & associated ramps from eclipse start to maximum
eclipse time.
2. Managing Solar generation increase & associated ramps from maximum eclipse to end
of eclipse.
3. Arranging power from alternate sources for meeting the demand which was generally
met from solar power.
Andhra Pradesh
Expected Solar reduction is 698 MW from 1960 to 1262 MW, the same can be managed with
available hydro station like Srisailam Right bank (7x110=770 MW) and Lower Sileru and other
stations. After maximum eclipse solar generation ramps up by 778 MW increment in 1hr 39
minutes, which has to be managed by ramping down hydro and thermal stations. AP has to
arrange power from other sources to the tune of 952 MW maximum to meet the demand. In
addition to above AP has to manage NPKUNTA generation variation in the form of schedule.
Solar eclipse, 21st June 2020 likely impacts and Preparedness- A report Page 58 of 99
S.NO. STATION EFFECTIVE INSTALLED
CAPACITY (MW)
1 UPPER SILERU 4x60 = 240.00
2 LOWER SILERU 4x115 = 460.00
3 SRISAILAM RBPH 7x110 = 770.00
TOTAL
1470.00
Table 18: Andhra Pradesh hydro generating stations
Karnataka
Expected Solar reduction is 826 MW from 2250 to 1424 MW, this can be managed with available
hydro station like Sharavathi (10x103.5=1035 MW) and Varahi itself. At the peak of eclipse all
hydro stations generation to be maximized and thermal generation needs to be ramped down
so that maximum fast ramping hydro generation would be available for managing solar
generation rise after eclipse. After maximum eclipse solar generation ramps up by 922 MW in
1hr 39 Min, which has to be managed by ramping down hydro and thermal also can be planned
to support hydro. Karnataka has to arrange power from other sources to the tune of 1194 MW
(maximum) to meet the demand. In addition to above Karnataka has to manage PAVAGADA
generation variation in the form of schedule.
S.NO. STATION EFFECTIVE INSTALLED CAPACITY
(MW)
1 SHARAVATHY 10x103.5 = 1035.00
2 NAGJHERI 1x135+5x150 = 885.00
3 SUPA 2x50 = 100.00
4 VARAHI 4x115 = 460.00
5 KADRA 3x50 = 150.00
6 KODASALLI 3x40 = 120.00
7 SHARAVATHI TAIL RACE 4x60 = 240.00
TOTAL 2990.00
Table 19: Karnataka hydro generating stations
Solar eclipse, 21st June 2020 likely impacts and Preparedness- A report Page 59 of 99
Telangana
Expected Solar reduction is 873 MW from 1799 to 926 MW, this can be managed with available
hydro station like Srisailam Left Bank (6x150=900 MW) and Nagarjuna Sagar
(1x110+7x100.8=815.6 MW) itself. At the peak of eclipse all hydro stations generation to be
maximized and thermal generation needs to be ramped down so that maximum fast ramping
hydro generation would be available for managing solar generation rise after eclipse. After
maximum eclipse solar generation ramps up 926 MW increment in just 1hr 39 Min, which has
to be managed by ramping down hydro and thermal also can be planned to support hydro. Both
Nagarjuna sagar and Srisailam Left bank are have pump operation facility, if required pump
mode operation also can be utilized. Telangana has to arrange power from other sources to the
tune of 1047 MW (maximum) to meet the demand.
S.NO. STATION EFFECTIVE INSTALLED
CAPACITY (MW)
1 SRISAILAM LBPH 6x150 = 900.00
2 N'SAGAR 1x110+7x100.8 = 815.60
TOTAL
1715.60
Table 20: Telangana hydro generating stations
Tamil Nadu
Expected Solar reduction is 451 MW from 1805 to 1354 MW, this can be managed with available
hydro station like Kadamparai (4x100=400 MW) and Kundah complex (~510 MW). At the peak
of eclipse all hydro stations generation to be maximized and thermal generation needs to be
ramped down so that maximum fast ramping hydro generation would be available for
managing Solar generation rise after eclipse. After maximum eclipse solar generation ramps up
by 546 MW in 1hr 39 Min, which has to be managed by ramping down hydro and thermal also
can be planned along with hydro. Tamil Nadu has to arrange power from other sources to the
tune of 526 MW (maximum) to meet the demand. Pump mode operation Kadamparai can be
utilized during solar generation rise time after eclipse.
Major hydro details of Tamil Nadu given below: -
Solar eclipse, 21st June 2020 likely impacts and Preparedness- A report Page 60 of 99
S.NO. STATION EFFECTIVE INSTALLED CAPACITY
(MW)
1 PYKARA ULTIMATE (PUSHEP) 3x50 = 150.00
2 KUNDAH-I to VI = 515.00
3 KADAMPARAI 4x100 = 400.00
4 ALIYAR 1x60 = 60.00
5 METTUR TUNNEL 4x50 = 200.00
6 LOWER METTUR BARRIAGE - 1 TO 4 8x15 = 120.00
7 PERIYAR 4x35 = 140.00
TOTAL 1585.00
Table 21: Tamil Nadu hydro generating stations
Southern Region ISTS connected solar plants
Expected ISTS connected solar generation reduction is 875 MW from 2578 to 1703 MW. After
maximum eclipse solar generation ramps up by 895 MW in 1hr 39 Min. There will be shortfall
of 1164 MW (maximum) compared to clear sky day. Reduction of ISTS connected solar will
reflect in states schedule only. Hence Karnataka has to manage state solar generation and
Pavagada solar reduction portion in the form of schedule. Similarly, Andhra Pradesh has to
manage state solar generation and NP Kunta solar reduction portion in the form of schedule.
State thermal generation also needs to be planned in coordination with State Hydro generation
so that additional support from thermal can be utilized.
ISGS generating units can be brought on bar from RSD based on 18th & 19th June 2020 reserve
availability and kept as reserve, for compensating regional entity solar generation reduction.
RRAS instructions: NLDC may give suitable RRAS instructions of RRAS UP during solar
generation reduction and RRAS DOWN during solar generation rise.
Solar generation reduction/increase during eclipse time can easily be managed with available
hydro generation of Southern Region (as this year reservoir positions are good). Pump mode
operation, thermal generation support, keeping reserves would be helpful in better managing
the situation.
Solar eclipse, 21st June 2020 likely impacts and Preparedness- A report Page 61 of 99
Chapter - 8 : Utility scale solar power plant controller
Working of PPC (Power Plant Controller) during solar eclipse
PPC (Power Plant Controller) has been installed at the point of interconnection to the grid or
reticulation system to control the behavior of the plant in accordance with mandates as per the
grid codes.
As per CEA (Technical Standards for Connectivity to the Grid) (Amendment) Regulations, 2019,
“(4) The generating stations with installed capacity of more than 10 MW connected at voltage
level of 33 kV and above –
(i) shall be equipped with the facility to control active power injection in accordance with
a set point, capable of being revised based on directions of the State Load Dispatch
Centre or Regional Load Dispatch Centre, as the case may be;
(ii) shall have governors or frequency controllers of the units at a droop of 3 to 6% and a
dead band not exceeding ±0.03 Hz:
Provided that for frequency deviations in excess of 0.3 Hz, the Generating Station shall
have the facility to provide an immediate (within 1 second) real power primary
frequency response of at least 10% of the maximum Alternating Current active power
capacity;
(iii) shall have the operating range of the frequency response and regulation system from
10% to 100% of maximum Alternating Current active power capacity, corresponding
to solar insolation or wind speed, as the case may be;
(iv) shall be equipped with the facility for controlling the rate of change of power output at
a rate not more than ± 10% per minute."
During a solar eclipse event, after the totality phase, the solar generators start ramping up their
power. At this time, it may be required to control the active power to avoid the situation of over-
frequency in the grid. At this time, the solar generation is supposed be ramped up in a controlled
manner with the proper droop settings. In case of over frequency, PPC at the solar generators
should be able to control the active power injection as per the set point.
All the solar generators having PPCs installed in the plant may be suggested to keep the PPCs
operational with the droop settings 3-4%.
Solar eclipse, 21st June 2020 likely impacts and Preparedness- A report Page 62 of 99
The operation of the PPCs of such plants may also be studied once the event is over. For that,
Solar plants having PPC may be asked to submit the active power injection pattern controlled
by the PPC during the event.
At present, 1780 MW capacity of solar plants in Northern region and 105MW capacity of solar
plants in Western Region and 250 MW capacity of solar plants in Southern region have PPC
installed.
Details of PPC installation at solar plants is attached as per Annexure-XI
Solar eclipse, 21st June 2020 likely impacts and Preparedness- A report Page 63 of 99
Chapter - 9 : Summary and Recommendations
Summary:
The solar eclipse is a predictable event where the generation is impacted for a known period of
time. With the present level of solar generation penetration, no reliability issue is observed with
anticipated all India solar reduction by 11943 MW w.r.t. normal day (assuming clear sky
condition). However, bus reactors/line reactors at large solar parks may be switched suitably
to control the voltages on respective solar nodes. The June month being the monsoon month in
the country, total solar generation may be lower on 21st June 2020. It would depend on the
reach and intensity of the monsoon in southern and central part of the country.
Based on previous solar eclipse event occurrences in India, it is expected that during eclipse on
21st June 2020, there would be depression in demand due to human behaviour. However, due
to ongoing countrywide lockdown, due to COVID-19, the reduction and increase in demand
could be less compared to previous eclipses because temples, malls are closed and small
commercial shops are either closed or opening on alternate days. Therefore, slowing down of
human activity in terms of cooking, agriculture and other day to day activities would lead to
decrease in power consumption. It is expected that All India average demand may reduce by
2-2.5% with instantaneous maximum reduction of 3-3.5 % and after eclipse it may increase by
the same amount.
Approximately 500-600 MW increase in drawl from the grid may be expected due to loss of
generation from solar roof top on all India basis. Therefore, minimum impact of solar roof top
has been considered.
The management of likely reduction in solar generation of 8900 MW with a ramp down rate of
102 MW/Minute and increase of 10362 MW after maximum eclipse time with a ramp up rate
of 104 MW/Minute requires high ramping resources with flexible characteristics. The high
ramping resources such as hydro and gas available in Northern, Southern and Western region
is proposed to be scheduled. All the states are advised to keep the sufficient reserves in their
hydro, gas and thermal plants to mitigate any contingency during real time. Further, it is
proposed to maintain the Load generation balance in their control area to avoid stress on the
inter-state/inter-region periphery. ISGS generating plants (Gas and Hydro) of NR and WR may
be scheduled from the plants given below as per the reduction /increase in solar generation.
Details are given below: -
Solar eclipse, 21st June 2020 likely impacts and Preparedness- A report Page 64 of 99
Name of the Station
Units Installed Capacity MW
Name of the Station
Units Installed Capacity MW
Gas Units Hydro Stations
Northern Region Northern Region
Dadri 2 * 154.51 +
4 * 130.19 830
Tehri Hps 4*250 1000
Anta 1 * 153.2 +
3 * 88.71 419
Koldam Hps 4*200 800
Auraiya 2 * 109.3 + 4 * 111.19
663
Chamera-I Hps 3*180 540
Total 1912 Chamera-III Hps 3*77 231
Western Region
Dhauliganga Hps 4*70 280
Kawas 4*106+2*216 856 Parbati-III Hps 4*130 520
Gandhar 3*144+1*255 687 Pong Hps 6*66 396
Total 1543
Bhakhra-L&R Hps
2 * 108 + 3 * 126 +
5 * 157 1379
Grand Total 3455 Total 5146
Western Region
SSP 200*6+5*50 1450
Total 1450
Grand Total 6596
Table 22: Northern and Western Region ISGS generating plants (Gas and Hydro)
State hydro generators mainly in Southern Region and Western Region may be scheduled to
tackle the solar generation reduction and subsequent increase after maximum eclipse time.
Based on the previous year’s inflows and scheduling of generators during the month of June, it
is expected that hydro generation of 3000-3500 MW in Northern Region,3300-3700 MW in
Southern Region and 2000 MW in Western Region could be available for flexing. Apart from
this, 1200-1300 MW of Gas based generation in Northern and Western Region could also be
available. Further, units under Reserve shutdown (RSD) in state control area and regional
control area may also be revived to maintain load generation balance during eclipse.
As per power system simulation study, the impact of eclipse on network loadings and voltages
suggest that network loadings are within operating limits. It has been observed that major line
loading as well as voltages at important nodes are within permissible limits.
Solar eclipse, 21st June 2020 likely impacts and Preparedness- A report Page 65 of 99
Recommendations:
(i) Power output from solar PV plants is highly dependent on obscuration due to solar
eclipse. Further, in view of weather conditions in June 2020, day ahead forecast will be
very important. Day ahead forecast may be generated through REMC/in-house model for
all regions /states considering the weather conditions and solar eclipse obscuration
factor. Day ahead forecast of solar generation is very important for 21st June 2020 for all
the plants/states/regions. Solar generation scheduling shall be done as per the forecasted
variation in generation due to solar eclipse.
(ii) Coordination among SLDCs /RLDCs and NLDC is required to address ramp issues.
(iii) Planned Shutdown of Conventional Power Stations / Transmission lines may be avoided
in all the regions on 21st June 2020
(iv) All the solar generators having PPCs installed (1780 MW in NR,105 MW in WR and 250
MW in SR) in the plant may be suggested to keep the PPCs operational with the droop
settings 3-4%.
(v) In order to cater the fast ramping down/up due to solar eclipse start/ end the following
procedure needs to be followed by all constituents
a) Keeping all reservoir based Hydro units on bar and maintaining generation at
minimum possible levels before start of the eclipse and picking the Hydro once
solar eclipse starts at 10:02 hrs.
b) Maintaining full generation at all the reservoir based Hydro stations during
eclipse peak at 11:50 hrs and start ramp down after completion of annularity of
eclipse to tackle ramping of solar generation.
c) Thermal generation, being slow ramping compared to Hydro/Gas, can also be
planned in similar manner to aid the support provided by Hydro stations in
catering the ramping requirements
d) All Hydro stations may be advised to operate in FGMO. Further Droop settings of
all hydro stations and gas stations may be reduced to 2 to 3%. Similarly drop of
thermal stations may also be reduced to 3 to 4%.
e) To maintain adequate spinning reserves in ISGS/SGS units closed under RSD may
be brought on-bar before onset of solar eclipse on 21st June 2020. Having
additional units would be helpful to meet ramp requirements as well.
Solar eclipse, 21st June 2020 likely impacts and Preparedness- A report Page 66 of 99
f) Resources must be identified and kept on bar to meet the variation in generation
from solar PV plants and behind-the-meter solar in all regions.
g) Generating stations may also be advised to generate/absorb VARs as per
capability curve.
h) STATCOMs, SVCs to be in service in voltage control mode (reference 1 pu).
i) All the bus reactors near solar generating stations to be switched on gradually
before the start of the eclipse (Particularly Bhadla in NR based on Bus voltage in
real time) and to be taken out as per grid voltage after 1200 hrs
j) All the defence mechanisms such as UFR, SPS,etc. shall be in service
k) Sensitise all the constituents in OCC /RPC (Operational coordination
committee/Regional power committee) meetings.
l) All regions should be ready for emergency support to each other.
m) HVDC set points may be kept such that adequate margin is available to tackle any
contingency during solar reduction.
n) SCED to be disabled before the eclipse to keep sufficient margins in inter-regional
corridors and ISGS plants
o) Load groups should not be taken in/out of service during eclipse period. Any
change in load profile should be carried out in consultation with RLDC/NLDC
Solar eclipse, 21st June 2020 likely impacts and Preparedness- A report Page 67 of 99
Annexure- I THE ANNULAR ECLIPSE OF THE SUN, JUNE 21, 2020
LOCAL CIRCUMSTANCES RELATING TO PLACES FROM WHERE ANNULAR PHASE IS VISIBLE
Places Annular phase Begins (IST)
Greatest Eclipse (IST)
Maximum. Obscuration
Annular phase Ends (IST)
Duration of Annularity
h m h m h m m s
Chamoli 12 08.7 12 09.1 98.6% 12 09.4 0 38
Dehradun 12 05.0 12 05.3 98.6% 12 05.6 0 31
Joshimath 12 09.5 12 09.8 98.6% 12 10.2 0 39
Kurukshetra 12 01.4 12 01.8 98.6% 12 02.1 0 39
Sirsa 11 55.9 11 56.1 98.6% 11 56.4 0 36
Suratgarh 11 52.5 11 52.9 98.6% 11 53.3 0 45
THE ANNULAR ECLIPSE OF THE SUN, JUNE 21, 2020 PHASES OF ECLIPSE VISIBLE FROM CERTAIN PLACES OF INDIA AND ITS NEIGHBOURHOOD
Places Partial Eclipse Begins (IST)
Position Angles at Eclipse Begins
Annular phase Begins (IST)
Greatest Eclipse (IST)
Magni- tude
Max-imum. Obscu-ration
Annular phase Ends (IST)
Partial Eclipse Ends (IST)
Position Angles at Eclipse Ends
Dura-tion of Eclipse
h m P V h m h m h m h m P V h m
Agartala 10 56.0 275 1 - - 12 45.1 0.771 71.1% - - 14 23.6 77 356 3 28
Ahmadabad 10 04.0 263 346 - - 11 42.2 0.823 77.4% - - 13 32.2 70 340 3 28
Aijwal 11 00.9 276 3 - - 12 49.8 0.770 70.9% - - 14 26.7 77 357 3 26
Ajmer 10 11.9 260 337 - - 11 51.9 0.906 87.9% - - 13 40.6 76 0 3 29
Allahabad 10 27.6 267 347 - - 12 13.6 0.831 78.4% - - 14 00.6 75 356 3 33
Amritsar 10 20.0 252 319 - - 11 57.7 0.935 91.5% - - 13 41.6 85 27 3 22
Bangalore 10 13.2 285 29 - - 11 47.6 0.473 36.5% - - 13 31.5 50 290 3 18
Bhagalpur 10 42.4 270 350 - - 12 30.9 0.811 76.0% - - 14 13.8 77 358 3 31
Bhopal 10 14.7 267 351 - - 11 57.4 0.789 73.2% - - 13 47.0 70 344 3 32
Bhubaneswar 10 38.3 279 17 - - 12 26.1 0.655 57.0% - - 14 09.7 67 338 3 31
Cannanore 10 06.7 285 28 - - 11 37.5 0.461 35.2% - - 13 20.4 47 274 3 14
*Chamoli 10 27.1 257 325 12 08.7 12 09.1 0.997 98.6% 12 09.4 13 53.7 84 16 3 27
Chandigarh 10 24.4 254 322 - - 12 04.5 0.965 95.4% - - 13 48.7 85 21 3 24
Chennai 10 22.0 288 35 - - 11 58.5 0.453 34.4% - - 13 40.8 50 298 3 19
Cochin 10 11.0 290 37 - - 11 38.9 0.396 28.4% - - 13 17.7 43 267 3 07
Cooch Behar 10 50.5 270 342 - - 12 39.0 0.846 80.3% - - 14 19.2 80 3 3 29
Cuttack 10 38.6 278 16 - - 12 26.6 0.661 57.8% - - 14 10.1 68 339 3 31
Darjeeling 10 47.2 268 339 - - 12 35.2 0.868 83.1% - - 14 16.3 81 5 3 29
Solar eclipse, 21st June 2020 likely impacts and Preparedness- A report Page 68 of 99
THE ANNULAR ECLIPSE OF THE SUN, JUNE 21, 2020 PHASES OF ECLIPSE VISIBLE FROM CERTAIN PLACES OF INDIA AND ITS NEIGHBOURHOOD
Places Partial Eclipse Begins (IST)
Position Angles at Eclipse Begins
Annular phase Begins (IST)
Greatest Eclipse (IST)
Magni- tude
Max-imum. Obscu-ration
Annular phase Ends (IST)
Partial Eclipse Ends (IST)
Position Angles at Eclipse Ends
Dura-tion of Eclipse
h m P V h m h m h m h m P V h m
*Dehradun 10 24.2 256 325 12 05.0 12 05.3 0.996 98.6% 12 05.6 13 50.4 83 17 3 26
Delhi 10 20.1 258 332 - - 12 01.6 0.952 93.7% - - 13 48.4 80 9 3 28
Dibrugarh 11 07.9 270 282 - - 12 54.7 0.896 86.5% - - 14 29.1 85 11 3 21
Dwarka 9 56.6 262 344 - - 11 31.1 0.840 79.5% - - 13 20.1 69 328 3 24
Gandhinagar 10 04.3 263 346 - - 11 42.6 0.827 77.9% - - 13 32.6 70 341 3 28
Gangtok 10 48.3 268 336 - - 12 36.2 0.877 84.2% - - 14 17.0 81 6 3 28
Gaya 10 36.2 270 352 - - 12 24.2 0.799 74.4% - - 14 08.9 75 355 3 33
Guwahati 10 57.0 271 338 - - 12 45.5 0.842 79.8% - - 14 23.6 81 4 3 27
Haridwar 10 24.9 256 324 - - 12 06.0 0.990 98.6% - - 13 50.8 84 18 3 26
Hazaribagh 10 37.2 272 356 - - 12 25.4 0.774 71.4% - - 14 09.9 74 352 3 33
Hubli 10 06.0 277 13 - - 11 42.6 0.586 49.1% - - 13 30.8 56 301 3 25
Hyderabad 10 15.0 278 14 - - 11 55.8 0.602 50.8% - - 13 43.9 59 316 3 29
Imphal 11 04.6 275 342 - - 12 53.0 0.804 75.0% - - 14 28.7 80 1 3 24
Itanagar 11 03.5 270 311 - - 12 51.1 0.879 84.4% - - 14 26.9 84 9 3 23
Jaipur 10 14.8 260 337 - - 11 55.8 0.908 88.1% - - 13 44.2 77 1 3 29
Jalandhar 10 22.7 252 318 - - 12 01.0 0.931 91.0% - - 13 44.5 86 27 3 22
Jammu 10 21.7 250 316 - - 11 58.5 0.904 87.5% - - 13 41.2 87 32 3 20
*Joshimath 10 27.8 257 325 12 09.5 12 09.8 0.997 98.6% 12 10.2 13 54.3 84 17 3 27
Kanyakumari 10 17.7 295 47 - - 11 41.9 0.329 21.9% - - 13 15.3 38 260 2 58
Kavalur 10 19.2 287 33 - - 11 55.1 0.458 34.9% - - 13 37.9 50 295 3 19
Kavaratti 10 00.3 284 26 - - 11 28.0 0.460 35.1% - - 13 09.7 45 256 3 09
Kohima 11 05.3 273 320 - - 12 53.3 0.835 78.9% - - 14 28.8 81 4 3 23
Kolhapur 10 03.2 275 9 - - 11 39.5 0.617 52.6% - - 13 28.3 57 301 3 25
Kolkata 10 46.4 276 8 - - 12 35.5 0.725 65.5% - - 14 17.0 73 349 3 31
Koraput 10 28.2 279 17 - - 12 13.5 0.619 52.8% - - 13 59.4 63 329 3 31
Kozikode 10 08.4 287 31 - - 11 38.5 0.439 32.9% - - 13 20.2 46 273 3 12
Kurnool 10 13.8 280 19 - - 11 52.6 0.554 45.4% - - 13 39.6 56 307 3 26
*Kurukshetra 10 21.3 256 326 12 01.4 12 01.8 0.997 98.6% 12 02.1 13 47.4 83 16 3 26
Lucknow 10 26.8 264 340 - - 12 11.8 0.879 84.4% - - 13 58.5 78 1 3 32
Madurai 10 17.6 292 42 - - 11 46.5 0.377 26.6% - - 13 24.3 43 274 3 07
Mangalore 10 04.9 283 23 - - 11 37.1 0.498 39.1% - - 13 21.8 49 279 3 17
Midnapore 10 43.0 276 7 - - 12 32.0 0.722 65.0% - - 14 14.5 72 348 3 31
Mount Abu 10 05.9 261 341 - - 11 44.3 0.868 83.0% - - 13 33.8 72 350 3 28
Mumbai 10 00.9 270 360 - - 11 37.5 0.697 62.1% - - 13 27.5 62 311 3 27
Murshidabad 10 47.0 273 357 - - 12 36.1 0.782 72.4% - - 14 17.5 76 356 3 30
Solar eclipse, 21st June 2020 likely impacts and Preparedness- A report Page 69 of 99
THE ANNULAR ECLIPSE OF THE SUN, JUNE 21, 2020 PHASES OF ECLIPSE VISIBLE FROM CERTAIN PLACES OF INDIA AND ITS NEIGHBOURHOOD
Places Partial Eclipse Begins (IST)
Position Angles at Eclipse Begins
Annular phase Begins (IST)
Greatest Eclipse (IST)
Magni- tude
Max-imum. Obscu-ration
Annular phase Ends (IST)
Partial Eclipse Ends (IST)
Position Angles at Eclipse Ends
Dura-tion of Eclipse
h m P V h m h m h m h m P V h m
Muzaffarpur 10 38.3 268 345 - - 12 26.0 0.841 79.7% - - 14 10.0 78 360 3 32
Mysore 10 10.7 286 29 - - 11 43.4 0.461 35.2% - - 13 26.5 48 283 3 16
Nagpur 10 17.9 272 1 - - 12 01.6 0.711 63.7% - - 13 50.7 67 335 3 33
Nalgonda 10 17.3 279 17 - - 11 58.4 0.582 48.6% - - 13 45.8 58 316 3 28
Nasik 10 03.8 269 357 - - 11 42.0 0.720 64.8% - - 13 32.3 64 321 3 29
Nellore 10 20.4 285 29 - - 11 59.0 0.499 39.3% - - 13 43.4 53 305 3 23
Nowgong 10 21.4 266 346 - - 12 05.8 0.830 78.3% - - 13 54.1 74 353 3 33
Panaji 10 03.3 277 12 - - 11 38.8 0.589 49.3% - - 13 26.9 55 296 3 24
Patna 10 37.1 269 348 - - 12 24.9 0.825 77.7% - - 14 09.3 77 358 3 32
Pondicherry 10 21.7 290 39 - - 11 56.0 0.423 31.2% - - 13 36.7 48 291 3 15
Port Blair 11 15.6 301 114 - - 12 53.4 0.393 28.1% - - 14 18.8 54 316 3 03
Pune 10 03.0 272 2 - - 11 40.5 0.675 59.5% - - 13 30.3 61 312 3 27
Puri 10 38.3 279 19 - - 12 26.0 0.641 55.4% - - 14 09.3 66 337 3 31
Raipur 10 25.1 274 5 - - 12 10.9 0.699 62.3% - - 13 58.4 68 338 3 33
Rajamundry 10 27.1 282 24 - - 12 10.6 0.564 46.5% - - 13 55.7 59 321 3 29
Rajkot 9 59.6 263 346 - - 11 35.8 0.819 77.0% - - 13 25.5 68 332 3 26
Ranchi 10 36.8 273 360 - - 12 25.0 0.753 68.8% - - 14 09.6 73 349 3 33
Sambalpur 10 32.2 275 7 - - 12 19.6 0.697 62.1% - - 14 05.3 69 341 3 33
Shillong 10 58.0 272 343 - - 12 46.6 0.826 77.8% - - 14 24.5 80 2 3 27
Shimla 10 23.5 254 322 - - 12 03.4 0.967 95.6% - - 13 47.9 85 21 3 24
Sibsagar 11 06.7 271 294 - - 12 54.0 0.879 84.4% - - 14 28.8 84 9 3 22
Silchar 11 01.0 274 349 - - 12 49.7 0.803 74.9% - - 14 26.6 79 0 3 26
Siliguri 10 47.3 269 341 - - 12 35.5 0.856 81.6% - - 14 16.7 80 4 3 29
Silvassa 10 02.4 268 355 - - 11 40.1 0.741 67.4% - - 13 30.4 65 322 3 28
*Sirsa 10 16.9 255 327 11 55.9 11 56.1 0.996 98.6% 11 56.6 13 42.3 82 16 3 25
Srinagar 10 24.2 248 310 - - 11 59.7 0.861 82.2% - - 13 40.6 90 39 3 16
Sringeri 10 06.7 282 22 - - 11 40.6 0.514 40.9% - - 13 26.2 51 287 3 20
*Suratgarh 10 14.5 255 327 11 52.5 11 52.9 0.998 98.6% 11 53.3 13 39.2 81 17 3 25
Tamelong 11 04.8 274 335 - - 12 53.1 0.814 76.4% - - 14 28.7 80 2 3 24
Thanjavur 10 20.3 291 41 - - 11 51.8 0.394 28.3% - - 13 30.8 45 283 3 10
Thiruvanantapuram 10 15.1 294 44 - - 11 40.0 0.346 23.5% - - 13 14.9 39 260 3 00
Tiruneveil 10 18.6 293 45 - - 11 45.9 0.356 24.5% - - 13 21.9 41 270 3 03
Trichur 10 10.7 288 34 - - 11 40.5 0.420 30.9% - - 13 21.2 45 273 3 10
Udaipur 10 07.8 262 343 - - 11 47.2 0.858 81.8% - - 13 36.8 72 350 3 29
Ujjain 10 10.9 266 350 - - 11 52.1 0.798 74.3% - - 13 42.2 70 342 3 31
Solar eclipse, 21st June 2020 likely impacts and Preparedness- A report Page 70 of 99
THE ANNULAR ECLIPSE OF THE SUN, JUNE 21, 2020 PHASES OF ECLIPSE VISIBLE FROM CERTAIN PLACES OF INDIA AND ITS NEIGHBOURHOOD
Places Partial Eclipse Begins (IST)
Position Angles at Eclipse Begins
Annular phase Begins (IST)
Greatest Eclipse (IST)
Magni- tude
Max-imum. Obscu-ration
Annular phase Ends (IST)
Partial Eclipse Ends (IST)
Position Angles at Eclipse Ends
Dura-tion of Eclipse
h m P V h m h m h m h m P V h m
Vadodara 10 04.6 265 349 - - 11 43.2 0.795 73.9% - - 13 33.5 68 335 3 29
Varanasi 10 31.0 268 348 - - 12 17.8 0.821 77.2% - - 14 04.0 76 356 3 33
Vijayawada 10 21.7 281 22 - - 12 03.4 0.558 45.9% - - 13 49.5 58 316 3 28
Chittagong 10 59.9 277 11 - - 12 49.0 0.749 68.3% - - 14 26.1 76 355 3 26
Colombo 10 30.8 300 60 - - 11 54.6 0.286 18.0% - - 13 23.8 37 268 2 53
Dhaka 10 54.1 274 358 - - 12 43.3 0.779 72.0% - - 14 22.4 77 357 3 28
Islamabad 10 21.8 247 310 - - 11 56.0 0.848 80.5% - - 13 36.5 90 43 3 15
Karachi 9 57.2 255 333 - - 11 30.0 0.952 93.6% - - 13 16.7 75 17 3 19
Kathmandu 10 39.5 264 335 - - 12 26.1 0.906 87.8% - - 14 09.3 82 7 3 30
Lahore 10 19.9 251 318 - - 11 57.0 0.922 89.8% - - 13 40.5 86 29 3 21
Rwalpindi 10 21.1 247 310 - - 11 55.3 0.852 81.1% - - 13 36.1 90 43 3 15
Thimpu 10 52.6 267 330 - - 12 40.3 0.893 86.1% - - 14 19.6 83 8 3 27
Yangon 11 19.0 290 135 - - 13 04.1 0.585 48.8% - - 14 33.3 68 341 3 14
Solar eclipse, 21st June 2020 likely impacts and Preparedness- A report Page 71 of 99
Annexure- II
Solar generation installed and telemetered capacity as on 31st March 2020
Region
State
Ground Mounted
(MW)
Ground Mounted
Telemetered (MW)
Roof Top (MW)
Telemetered Roof Top
(MW)
Southern Region
Andhra Pradesh 3521.99 3221 88.03 0 Karnataka 7045 7045 232.77 0 Kerala 100.00 87 42.23 0 Tamil Nadu 3759.89 2970 155.99 0 Telangana 3530.29 3473 90.46 0 Pondicherry 0.03 0 5.48 0 Total 17957.36 16796.00 614.96 0.00
Western Region
Chhattisgarh 215.83 166 15.52 0 Goa 0.95 0 3.83 0 Gujarat 2426.44 2249 521.93 0 Madhya Pradesh 2208.48 2199 49.98 0 Maharashtra 1582.24 1582 219.56 0 Dadar & Nagar Haveli 2.49 0 2.97 0 Daman & Diu 10.15 0 9.71 0 Total 6446.58 6196.00 823.50 0.00
Northern Region
Chandigarh 6 0 34 0 Delhi 9 0 156 0 Haryana 131 59 121 0 Himachal Pradesh 17 0 16 0 Jammu & Kashmir 8 0 11 0 Punjab 829 829 119 0 Rajasthan 4883 4883 255 0 Uttar Pradesh 949 899 146 0 Uttarakhand 240 100 76 0 Total 7072 6770 934 0.00
Eastern Region
Bihar 138.93 25 12.64 0 Jharkhand 19.05 0 19.35 0 Odisha 383.56 40 14.28 0 Sikkim 0.00 0 0.07 0 West Bengal 70.00 0 44.46 0 Total 611.54 65 90.80 0.00
North Eastern Region
Arunachal Pradesh 1.27 0 4.34 0 Assam 10.67 0 30.56 0 Manipur 0.00 0 5.16 0 Meghalaya 0.00 0 0.12 0 Mizoram 0.10 0 1.42 0 Nagaland 0.00 0 1.00 0 Tripura 5.00 0 4.41 0 Total 17.04 0.00 47.01 0.00
Andaman & Nicobar 7.60 0 4.59 0
Lakshadweep
0.75 0 0 0
All India
Total 32112.51 29827.00 2515.31 0.00
Solar eclipse, 21st June 2020 likely impacts and Preparedness- A report Page 72 of 99
Annexure- III
Region, State and ISTS connected solar generation ramp rate
Figure 45:Northern Region normal vs estimated solar generation ramp rate on 21st June 2020
Figure 46:Western Region normal vs estimated solar generation ramp rate on 21st June 2020
-60
-40
-20
0
20
40
60
05
:46
06
:16
06
:46
07
:16
07
:46
08
:16
08
:46
09
:16
09
:46
10
:16
10
:46
11
:16
11
:46
12
:16
12
:46
13
:16
13
:46
14
:16
14
:46
15
:16
15
:46
16
:16
16
:46
17
:16
17
:46
18
:16
18
:46
19
:16
MW
/Min
ute
Time
Northern Region Solar Generation Ramp Rate
Actual ramp rate during clear sky condition Estimated ramp rate during solar eclipse
-100
-80
-60
-40
-20
0
20
40
60
80
100
05
:46
06
:16
06
:46
07
:16
07
:46
08
:16
08
:46
09
:16
09
:46
10
:16
10
:46
11
:16
11
:46
12
:16
12
:46
13
:16
13
:46
14
:16
14
:46
15
:16
15
:46
16
:16
16
:46
17
:16
17
:46
18
:16
18
:46
19
:16
MW
/Min
ute
Time
Western Region Solar Generation Ramp RateActual ramp rate during clear sky condition Estimated ramp rate during solar eclipse
Solar eclipse, 21st June 2020 likely impacts and Preparedness- A report Page 73 of 99
Figure 47: Southern Region normal vs estimated solar generation ramp rate on 21st June 2020
Figure 48: NR ISTS connected solar normal vs estimated ramp rate on 21st June 2020
-250
-200
-150
-100
-50
0
50
100
150
05
:46
06
:17
06
:48
07
:19
07
:50
08
:21
08
:52
09
:23
09
:54
10
:25
10
:56
11
:27
11
:58
12
:29
13
:00
13
:31
14
:02
14
:33
15
:04
15
:35
16
:06
16
:37
17
:08
17
:39
18
:10
18
:41
19
:12
MW
/Min
ute
Time
Southern Region Solar Generation Ramp Rate
Actual ramp rate during clear sky condition Estimated ramp rate during solar eclipse
-20
-15
-10
-5
0
5
10
15
20
25
05
:46
06
:16
06
:46
07
:16
07
:46
08
:16
08
:46
09
:16
09
:46
10
:16
10
:46
11
:16
11
:46
12
:16
12
:46
13
:16
13
:46
14
:16
14
:46
15
:16
15
:46
16
:16
16
:46
17
:16
17
:46
18
:16
18
:46
19
:16
MW
/Min
ute
Time
Actual ramp rate during clear sky condition Estimated ramp rate during solar eclipse
ISTS Connected Solar Generation Ramp Rate in Northern Region
Solar eclipse, 21st June 2020 likely impacts and Preparedness- A report Page 74 of 99
Figure 49:WR ISTS connected solar normal vs estimated ramp rate on 21st June 202
Figure 50 : SR ISTS connected solar normal vs estimated ramp rate on 21st June 2020
-25
-20
-15
-10
-5
0
5
10
15
20
05
:46
06
:17
06
:48
07
:19
07
:50
08
:21
08
:52
09
:23
09
:54
10
:25
10
:56
11
:27
11
:58
12
:29
13
:00
13
:31
14
:02
14
:33
15
:04
15
:35
16
:06
16
:37
17
:08
17
:39
18
:10
18
:41
19
:12
MW
/Min
ute
Time
Actual ramp rate during clear sky condition Estimated ramp rate during solar eclipse
ISTS Connected Solar Generation Ramp Rate in Western Region
-40
-30
-20
-10
0
10
20
30
40
05
:46
06
:17
06
:48
07
:19
07
:50
08
:21
08
:52
09
:23
09
:54
10
:25
10
:56
11
:27
11
:58
12
:29
13
:00
13
:31
14
:02
14
:33
15
:04
15
:35
16
:06
16
:37
17
:08
17
:39
18
:10
18
:41
19
:12
MW
/Min
ute
Time
Actual ramp rate during clear sky condition Estimated ramp rate during solar eclipse
ISTS Connected Solar Generation Ramp Rate in Southern Region
Solar eclipse, 21st June 2020 likely impacts and Preparedness- A report Page 75 of 99
Figure 51: Rajasthan normal vs estimated solar generation ramp rate on 21st June 2020
Figure 52: Punjab normal vs estimated solar generation ramp rate on 21st June 2020
-30
-20
-10
0
10
20
30
05
:46
06
:16
06
:46
07
:16
07
:46
08
:16
08
:46
09
:16
09
:46
10
:16
10
:46
11
:16
11
:46
12
:16
12
:46
13
:16
13
:46
14
:16
14
:46
15
:16
15
:46
16
:16
16
:46
17
:16
17
:46
18
:16
18
:46
19
:16
MW
/Min
ute
Time
Rajasthan Solar Generation Ramp Rate
Actual ramp rate during clear sky condition Estimated ramp rate during solar eclipse
-8
-6
-4
-2
0
2
4
6
8
10
05
:46
06
:16
06
:46
07
:16
07
:46
08
:16
08
:46
09
:16
09
:46
10
:16
10
:46
11
:16
11
:46
12
:16
12
:46
13
:16
13
:46
14
:16
14
:46
15
:16
15
:46
16
:16
16
:46
17
:16
17
:46
18
:16
18
:46
19
:16
MW
/Min
ute
Time
Punjab Solar Generation Ramp Rate
Actual ramp rate during clear sky condition Estimated ramp rate during solar eclipse
Solar eclipse, 21st June 2020 likely impacts and Preparedness- A report Page 76 of 99
Figure 53: Uttar Pradesh normal vs estimated solar generation ramp rate on 21st June 2020
Figure 54: Gujarat normal vs estimated solar generation ramp rate on 21st June 2020
-20
-15
-10
-5
0
5
10
05
:46
06
:16
06
:46
07
:16
07
:46
08
:16
08
:46
09
:16
09
:46
10
:16
10
:46
11
:16
11
:46
12
:16
12
:46
13
:16
13
:46
14
:16
14
:46
15
:16
15
:46
16
:16
16
:46
17
:16
17
:46
18
:16
18
:46
19
:16
MW
/Min
ute
Time
Uttar Pradesh Solar Generation Ramp Rate
Actual ramp rate during clear sky condition Estimated ramp rate during solar eclipse
-20
-15
-10
-5
0
5
10
15
20
25
30
05:4
606
:12
06:3
807
:04
07:3
007
:56
08:2
2
08:4
809
:14
09:4
0
10:0
6
10:3
2
10:5
8
11:2
411
:50
12:1
6
12:4
213
:08
13:3
4
14:0
014
:26
14:5
2
15:1
8
15:4
416
:10
16:3
6
17:0
217
:28
17:5
4
18:2
0
18:4
619
:12
MW
/Min
ute
Time
Gujarat Solar Generation Ramp Rate
Actual ramp rate during clear sky condition Estimated ramp rate during solar eclipse
Solar eclipse, 21st June 2020 likely impacts and Preparedness- A report Page 77 of 99
Figure 55: Maharashtra normal vs estimated solar generation ramp rate on 21st June 2020
Figure 56: Madhya Pradesh normal vs estimated solar generation ramp rate on 21st June 2020
-100
-80
-60
-40
-20
0
20
40
60
80
100
05
:46
06
:17
06
:48
07
:19
07
:50
08
:21
08
:52
09
:23
09
:54
10
:25
10
:56
11
:27
11
:58
12
:29
13
:00
13
:31
14
:02
14
:33
15
:04
15
:35
16
:06
16
:37
17
:08
17
:39
18
:10
18
:41
19
:12
MW
/Min
ute
Time
Maharashtra Solar Generation Ramp Rate
Actual ramp rate during clear sky condition Estimated ramp rate during solar eclipse
-25
-20
-15
-10
-5
0
5
10
15
20
25
30
05
:46
06
:16
06
:46
07
:16
07
:46
08
:16
08
:46
09
:16
09
:46
10
:16
10
:46
11
:16
11
:46
12
:16
12
:46
13
:16
13
:46
14
:16
14
:46
15
:16
15
:46
16
:16
16
:46
17
:16
17
:46
18
:16
18
:46
19
:16
MW
/Min
ute
Time
Madhya Pradesh Solar Generation Ramp Rate
Actual ramp rate during clear sky condition Estimated ramp rate during solar eclipse
Solar eclipse, 21st June 2020 likely impacts and Preparedness- A report Page 78 of 99
Figure 57: Chhattisgarh normal vs estimated solar generation ramp rate on 21st June 2020
Figure 58 : Andhra Pradesh normal vs estimated solar generation ramp rate on 21st June 2020
-1.5
-1
-0.5
0
0.5
1
1.5
1
32
63
94
12
5
15
6
18
7
21
8
24
9
28
0
31
1
34
2
37
3
40
4
43
5
46
6
49
7
52
8
55
9
59
0
62
1
65
2
68
3
71
4
74
5
77
6
80
7
MW
/Min
ute
Time
Chhattisgarh Solar Generation Ramp Rate
Estimated ramp rate during solar eclipse Estimated ramp rate during solar eclipse
-40
-30
-20
-10
0
10
20
30
40
05
:46
06
:16
06
:46
07
:16
07
:46
08
:16
08
:46
09
:16
09
:46
10
:16
10
:46
11
:16
11
:46
12
:16
12
:46
13
:16
13
:46
14
:16
14
:46
15
:16
15
:46
16
:16
16
:46
17
:16
17
:46
18
:16
18
:46
19
:16
MW
/Min
ute
Time
Andhra Pradesh Solar Generation Ramp Rate
Actual ramp rate during clear sky condition Estimated ramp rate during solar eclipse
Solar eclipse, 21st June 2020 likely impacts and Preparedness- A report Page 79 of 99
Figure 59: Karnataka normal vs estimated solar generation ramp rate on 21st June 2020
Figure 60: Tamil Nadu normal vs estimated solar generation ramp rate on 21st June 2020
-80
-60
-40
-20
0
20
40
60
05
:46
06
:16
06
:46
07
:16
07
:46
08
:16
08
:46
09
:16
09
:46
10
:16
10
:46
11
:16
11
:46
12
:16
12
:46
13
:16
13
:46
14
:16
14
:46
15
:16
15
:46
16
:16
16
:46
17
:16
17
:46
18
:16
18
:46
19
:16
MW
/Min
ute
Time
Karnataka Solar Generation Ramp Rate
Actual ramp rate during clear sky condition Estimated ramp rate during solar eclipse
-80
-60
-40
-20
0
20
40
60
80
100
05
:46
06
:16
06
:46
07
:16
07
:46
08
:16
08
:46
09
:16
09
:46
10
:16
10
:46
11
:16
11
:46
12
:16
12
:46
13
:16
13
:46
14
:16
14
:46
15
:16
15
:46
16
:16
16
:46
17
:16
17
:46
18
:16
18
:46
19
:16MW
/Min
ute
Time
Tamil Nadu Solar Generation Ramp Rate
Actual ramp rate during clear sky condition Estimated ramp rate during solar eclipse
Solar eclipse, 21st June 2020 likely impacts and Preparedness- A report Page 80 of 99
Figure 61 : Telangana normal vs estimated solar generation ramp rate on 21st June 2020
-40
-30
-20
-10
0
10
20
30
05
:46
06
:17
06
:48
07
:19
07
:50
08
:21
08
:52
09
:23
09
:54
10
:25
10
:56
11
:27
11
:58
12
:29
13
:00
13
:31
14
:02
14
:33
15
:04
15
:35
16
:06
16
:37
17
:08
17
:39
18
:10
18
:41
19
:12
MW
/min
ute
Time
Telangana Solar Generation Ramp Rate
Actual ramp rate during clear sky condition Estimated ramp rate during solar eclipse
Solar eclipse, 21st June 2020 likely impacts and Preparedness- A report Page 81 of 99
Annexure- IV
Load generation balance (LGB) in study cases
S.No. Name of State/Region Load (MW) Generation (MW)
Base Case -10:00 hrs
Eclipse Case -11:50 hrs
Base Case -10:00 hrs
Eclipse Case -11:50 hrs
I NORTHERN REGION
1 Punjab 9110 9291 4475 4276 2 Haryana 7425 7573 2422 2534 3 Rajasthan 8905 9082 7119 5926 4 Delhi 4488 4578 744 779 5 Uttar Pradesh 14870 15166 8887 8886 6 Uttarakhand 1685 1719 1047 1047
7 Himachal Pradesh
1363 1390 849 849
8 Jammu & Kashmir
2198 2241 1062 1062
9 Chandigarh 247 252 0 0 10 ISGS/IPPs 23 24 16949 20459 Total NR 50317 51316 43555 45818
II EASTERN REGION
1 Bihar 3863 3982 94 99 2 Jharkhand 878 909 360 364
3 Damodar Valley Corporation
2116 2191 3573 3705
4 Orissa 3426 3547 2235 2500 5 West Bengal 6284 6438 4236 4707 6 Sikkim 37 38 0 0 7 Bhutan 175 175 621 621 8 ISGS/IPPs -175 -175 9370 10013 Total ER 16604 17104 20490 22008
III WESTERN REGION
1 Maharashtra 17942 18358 10893 10959 2 Gujarat 12966 13266 9553 8972 3 Madhya Pradesh 7289 7457 4896 4439 4 Chhattisgarh 3027 3095 1819 1849 5 Daman and Diu 248 254 0 0
6 Dadra and Nagar Haveli
648 663 0 0
7 Goa-WR 375 384 0 0 8 ISGS/IPPs 1371 1388 28559 29151 Total WR 43865 44865 55720 55371
Solar eclipse, 21st June 2020 likely impacts and Preparedness- A report Page 82 of 99
Load generation balance (LGB) in study cases
S.No. Name of State/Region Load (MW) Generation (MW)
Base Case -10:00 hrs
Eclipse Case -11:50 hrs
Base Case -10:00 hrs
Eclipse Case -11:50 hrs
IV SOUTHERN REGION
1 Andhra Pradesh 7450 7562 4276 4704 2 Telangana 5870 5915 4100 3408 3 Karnataka 9239 9374 6676 6883 4 Tamil Nadu 11290 11458 6422 6368 5 Kerala 2412 2448 828 1179 6 Pondy 276 280 0 0 7 Goa-SR 66 67 0 0 8 ISGS/IPPs 0 0 9925 9250 Total SR 36604 37104 32227 31793
V NORTH-EASTERN REGION
1 Arunachal Pradesh
59 59 4 4
2 Assam 920 920 160 160 3 Manipur 107 107 0 0 4 Meghalaya 219 219 80 80 5 Mizoram 70 70 24 24 6 Nagaland 101 101 20 20 7 Tripura 93 93 32 32 8 ISGS/IPPs 141 141 1830 1955 Total NER 1710 1710 2150 2275
Total All India 149100 152100 154142 157265
Solar eclipse, 21st June 2020 likely impacts and Preparedness- A report Page 83 of 99
Annexure- V
Solar Generation Details in the Base Case
S. No.
Region State/Plant
Solar Generation in
Base Case (10:00 hrs)
Solar Generation in Eclipse Case (11:50 hrs)
Difference
1
Northern
Rajasthan 1684 303 1381 2 Punjab 360 10 350 3 UP 350 80 270 4 NR ISTS 1435 230 1205 Total NR 3829 623* 3206 5
Western
Gujarat 1208 483 725 6 Maharashtra 420 252 168 7 Madhya Pradesh 933 261 672 8 Chhattisgarh 24 10 14
9
WR ISTS (RUMS - ACME, ARISUN, Mahindra)
619 247 372
Total WR 3204 1253 1951 10
Southern
Andhra Pradesh 1716 1235 481 11 Telangana 1665 900 765 12 Karnataka 2091 1505 586 13 Tamil Nadu 1575 1400 175
14 SR ISTS (Pavagada, NP Kunta)
2500 1600 900
Total SR 9547 6640 2907 Total All India 16580 8255 8064
* In NR, details of connectivity of some small solar plants are not available. Reduction in generation in those plants during eclipse has been considered through increase in demand in respective areas. All figures are in MW
Solar eclipse, 21st June 2020 likely impacts and Preparedness- A report Page 84 of 99
Annexure- VI
Details of Increase in Generation Hydro
Region Plants Increase in generation (MW)
NR
Nathpa Jhakri 0 Karcham 0 Dulhasti 0 Tehri 490 Koldam 770 Chamera I, II & III 770 Rampur 0 Bhakra 450 Pong 400 Parbati I, II & III 520 Sewa-II 0 Dhauliganga 280 Bairasul 0
ER
Teesta - III 250 Purulia 450 Indravati 0 Balimela 200 Upper Kolab 50
WR
Koyna 0 Omkareshwar 60 Indira Sagar 100 SSP 0
SR
N'sagar 0 Srisailam LB 0 Kundah 0 Sharavathi 400 Kadamparai 0 Nagjheri 300 Iduki 300 Lower Periyar 50
NER Ranganadi 100 Loktak 35
Total 5975 Gas
Region Plants Increase in generation (MW)
WR Kawas 200 Gandhar 200
NR Dadri 280 Anta 120 Auraiya 200
Total 1000 Thermal
Region Plants Increase in generation (MW) All India Thermal 3700
Total 10675
Solar eclipse, 21st June 2020 likely impacts and Preparedness- A report Page 85 of 99
Annexure- VII
Maximum and minimum voltages at 400 kV level and above observed in the eclipse case
Voltages below 0.99 pu (400 kV level and above)
BUS ID STATION NAME Voltage V(PU) V(KV)
254025 JP_GZW_HVDC 400 0.98 392
254020 BOLANGIR 400 0.98 393
424014 BHADRAWATHI 400 0.98 393
134037 BABAI 400 0.99 395
Voltages above 1.03 pu (400 kV level)
BUS ID STATION NAME Voltage V(PU) V(KV) 414044 RYTPS 400 1.067 426.8 444041 RASIPALYAM 400 1.0546 421.8 414046 KALIKIRI 400 1.0518 420.7 434013 HASSAN 400 1.0512 420.5 444043 THAPPUGUNDU 400 1.051 420.4 414004 CHINAKMPALLI400.00 400 1.0489 419.6 414039 SRIKAKULAM 400 1.0476 419.0
424005 SRISAILAMLB 400 1.0469 418.8 414049 CPETA_PG 400 1.0463 418.5 414037 NP KUNTA 400 1.0458 418.3 414021 SATTENAPALLI400.00 400 1.0444 417.7 154076 BANDA 400 1.0415 416.6 414043 PODILI 400 1.0414 416.6 414047 HINDUPUR 400 1.0402 416.1 424019 DINDI 400 1.0401 416.0 334044 RGPPL 400 1.04 416.0 154074 ORAI4 400 1.0395 415.8 414002 CHITTOOR 400 1.0387 415.5
334060 NANDED 400 1.0386 415.4 434008 TUMKUR 400 1.0381 415.3 444015 PUGALUR 400 1.037 414.8 444024 TIRUVALAM-PG 400 1.0367 414.7 444031 TIRUVALAM-TN 400 1.0367 414.7 154086 ORAI (PG) 400 1.0367 414.7 414005 CNP-FSC1 400 1.0366 414.7 414006 CNP-FSC2 400 1.0364 414.5 414013 VTS-IV 400 1.0358 414.3 424020 ASUPAKA 400 1.0357 414.3 414031 KURNOOL-PG 400 1.0354 414.1
414001 GOOTY 400 1.0348 413.9 414032 GTYNLM-FSC 400 1.0348 413.9
Solar eclipse, 21st June 2020 likely impacts and Preparedness- A report Page 86 of 99
Voltages above 1.03 pu (400 kV level)
BUS ID STATION NAME Voltage V(PU) V(KV) 414033 GTYSMN-FSC 400 1.0348 413.9 414008 NUNNA 400 1.0347 413.9 134020 SIKAR 400 1.0346 413.8 124026 KURUKSHETRA_ 400 1.0345 413.8 334013 PADGHE 400 1.0344 413.8 334027 NAGOTHANE 400 1.0343 413.7 414010 KURNOOL 400 1.0342 413.7
414040 VEMAGIRI_PG 400 1.0342 413.7 174016 KALA AMB 400 1.0333 413.3 154005 PARICHHA 400 1.0323 412.9 414041 GHANI 400 1.0323 412.9 434021 UDUPI 400 1.0323 412.9 444037 KARAMADAI 400 1.0322 412.9 334064 PADGHE-GIS 400 1.0321 412.8 414019 LANCO 400 1.0319 412.8 334048 AURANGABD-PG 400 1.0315 412.6 124025 MAHIN_HV 400 1.0314 412.6 174014 SORANG 400 1.0314 412.6
424016 SURYAPET 400 1.0314 412.6 444003 SALEM-PG 400 1.0313 412.5 314014 SAMI 400 1.0312 412.5 334070 WARORA PS 400 1.0311 412.4 124999 DHANONDABYPA400.00 400 1.031 412.4 334066 KUDUS-MSETCL400.00 400 1.0308 412.3 444007 KALIVNDPATTU400.00 400 1.0305 412.2 414036 JAMALAMADUGU400.00 400 1.0304 412.2 444011 ARASUR 400 1.0304 412.2 354052 JAGDALPUR 400 1.0304 412.2 154063 REWAROAD 400 1.0302 412.1
414007 TALLAPALLI 400 1.0301 412.0 114005 RAJPURA_TH 400 1.03 412.0 154078 UNCHAHAR 400 1.03 412.0 174008 NATHPA4 400 1.03 412.0 324049 KIRNAPUR-MP 400 1.03 412.0
Voltages above 1.03 pu (765 kV level)
BUS ID STATION NAME Voltage V(PU) V(KV)
417005 CUDDAPAH-PG 765 1.0553 807.3
417003 SRIKAKULAM 765 1.0512 804.2
417006 CPETA-PG 765 1.0488 802.4
417004 VEMAGIRI_PG 765 1.0453 799.7
337005 AURANGABD-PG765.00 765 1.0452 799.6
Solar eclipse, 21st June 2020 likely impacts and Preparedness- A report Page 87 of 99
Voltages above 1.03 pu (765 kV level)
BUS ID STATION NAME Voltage V(PU) V(KV)
337009 PUNE GIS-PG 765 1.0395 795.2
117000 MOGA-PG 765 1.0383 794.3
337003 WARDHA-PG 765 1.0371 793.4
417001 KURNOOL-PG 765 1.0371 793.4
447002 TIRUVALAM 765 1.0367 793.1
337004 SOLAPUR-PG 765 1.0367 793.0
327013 STNAORAI 765 1.0358 792.4
337012 NEW PARLI-PG 765 1.035 791.8
327009 JABALPUR-PS 765 1.0345 791.4
157017 ORAI 765 1.0333 790.5
327014 GWLORAI 765 1.0331 790.3
337013 WARORA-PS 765 1.0328 790.1
337010 PADGHE-GIS 765 1.0321 789.6
327012 GADARWADANTP 765 1.031 788.7
427001 NIZAMABAD 765 1.0303 788.2
Solar eclipse, 21st June 2020 likely impacts and Preparedness- A report Page 88 of 99
Annexure- VIII
Northern Region gas-based stations 5-minute schedule Time ANTA AURAIYA 10:15 30 30 30 0 30 30 30 30 0 0 10:20 30 30 30 0 49 30 30 30 0 0 10:25 30 30 30 0 49 49 30 30 0 0 10:30 30 30 30 0 49 49 49 30 0 0 10:35 45 30 30 0 49 49 49 49 0 0 10:40 45 45 30 0 68 49 49 49 0 0 10:45 45 45 45 0 68 68 49 49 0 0 10:50 60 45 45 0 68 68 68 49 0 0 10:55 60 60 45 0 68 68 68 68 0 0 11:00 60 60 60 0 85 68 68 68 0 0 11:05 75 60 60 0 85 85 68 68 0 0 11:10 75 75 60 0 85 85 85 68 0 0 11:15 75 75 75 0 85 85 85 85 0 0 11:20 89 75 75 0 110 85 85 85 0 0 11:25 89 89 75 0 110 110 85 85 0 0 11:30 89 89 89 0 110 110 110 85 0 0 11:35 89 89 89 0 110 110 110 110 0 0 11:40 89 89 89 0 110 110 110 110 0 0 11:45 89 89 89 0 110 110 110 110 0 0 11:50 89 89 89 0 110 110 110 110 0 0 11:55 89 89 89 0 110 110 110 110 0 0 12:00 89 89 89 0 110 110 110 110 0 0 12:05 89 89 89 0 110 110 110 85 0 0 12:10 89 89 75 0 110 110 85 85 0 0 12:15 89 75 75 0 110 85 85 85 0 0 12:20 75 75 75 0 85 85 85 85 0 0 12:25 75 75 60 0 85 85 85 68 0 0 12:30 75 60 60 0 85 85 68 68 0 0 12:35 60 60 60 0 85 68 68 68 0 0 12:40 60 60 45 0 68 68 68 68 0 0 12:45 60 45 45 0 68 68 68 49 0 0 12:50 45 45 45 0 68 68 49 49 0 0 12:55 45 45 30 0 68 49 49 49 0 0 13:00 45 30 30 0 49 49 49 49 0 0 13:05 30 30 30 0 49 49 49 30 0 0 13:10 30 30 30 0 49 49 30 30 0 0 13:15 30 30 30 0 49 30 30 30 0 0 13:20 0 30 30 0 0 30 30 30 0 0 13:25 0 30 30 0 0 0 30 30 0 0 13:30 0 30 30 0 0 0 30 30 0 0 13:35 0 30 30 0 0 0 30 30 0 0 13:40 0 30 30 0 0 0 30 30 0 0 13:45 0 30 30 0 0 0 30 30 0 0 13:50 0 30 30 0 0 0 30 30 0 0
Solar eclipse, 21st June 2020 likely impacts and Preparedness- A report Page 89 of 99
Northern Region gas-based stations 5-minute schedule
Time DADRI Schedule (MW) Total NR Gas Generation Schedule
(Anta+Auraiya+Dadri) (MW) 10:15 30 30 30 30 0 0 330 10:20 30 30 30 30 0 0 349 10:25 30 30 30 30 0 0 368 10:30 55 30 30 30 0 0 412 10:35 55 55 30 30 0 0 471 10:40 55 55 55 30 0 0 530 10:45 55 55 55 55 0 0 589 10:50 70 55 55 55 0 0 638 10:55 70 70 55 55 0 0 687 11:00 70 70 70 55 0 0 734 11:05 70 70 70 70 0 0 781 11:10 95 70 70 70 0 0 838 11:15 95 95 70 70 0 0 895 11:20 95 95 95 70 0 0 959 11:25 95 95 95 95 0 0 1023 11:30 130 95 95 95 0 0 1097 11:35 130 130 95 95 0 0 1157 11:40 130 130 130 95 0 0 1192 11:45 130 130 130 130 0 0 1227 11:50 130 130 130 130 0 0 1227 11:55 130 130 130 95 0 0 1192 12:00 130 130 95 95 0 0 1157 12:05 130 95 95 95 0 0 1097 12:10 95 95 95 95 0 0 1023 12:15 95 95 95 70 0 0 959 12:20 95 95 70 70 0 0 895 12:25 95 70 70 70 0 0 838 12:30 70 70 70 70 0 0 781 12:35 70 70 70 55 0 0 734 12:40 70 70 55 55 0 0 687 12:45 70 55 55 55 0 0 638 12:50 55 55 55 55 0 0 589 12:55 55 55 55 30 0 0 530 13:00 55 55 30 30 0 0 471 13:05 55 30 30 30 0 0 412 13:10 30 30 30 30 0 0 368 13:15 30 30 30 30 0 0 349 13:20 30 30 30 30 0 0 270 13:25 0 30 30 30 0 0 210 13:30 0 0 30 30 0 0 180 13:35 0 0 30 30 0 0 180 13:40 0 0 30 30 0 0 180 13:45 0 0 30 30 0 0 180 13:50 0 0 30 30 0 0 180
Solar eclipse, 21st June 2020 likely impacts and Preparedness- A report Page 90 of 99
Annexure- IX
Northern Region Hydro generating stations 5-minute schedule
Time TEHRI Schedule (MW) Dhauliganga Schedule (MW)
10:15 25 0 0 0 0 0 0 0 10:20 70 25 0 0 0 0 0 0 10:25 122 70 25 0 0 0 0 0 10:30 122 122 70 25 0 0 0 0 10:35 122 122 122 70 0 0 0 0 10:40 122 122 122 122 0 0 0 0 10:45 122 122 122 122 0 0 0 0 10:50 122 122 122 122 0 0 0 0 10:55 122 122 122 122 0 0 0 0 11:00 122 122 122 122 60 0 0 0 11:05 122 122 122 122 60 10 10 0 11:10 122 122 122 122 60 60 10 10 11:15 122 122 122 122 60 60 60 10 11:20 122 122 122 122 70 60 60 60 11:25 122 122 122 122 70 70 70 70 11:30 122 122 122 122 70 70 70 70 11:35 122 122 122 122 70 70 70 70 11:40 122 122 122 122 70 70 70 70 11:45 122 122 122 122 70 70 70 70 11:50 122 122 122 122 70 70 70 70 11:55 122 122 122 122 70 70 70 70 12:00 122 122 122 122 70 70 70 70 12:05 122 122 122 122 70 70 70 70 12:10 122 122 122 122 70 60 60 60 12:15 122 122 122 122 60 60 60 10 12:20 122 122 122 122 60 60 10 10 12:25 122 122 122 122 60 10 10 0 12:30 122 122 122 122 60 0 0 0 12:35 122 122 122 122 0 0 0 0 12:40 122 122 122 122 0 0 0 0 12:45 122 122 122 122 0 0 0 0 12:50 122 122 122 122 0 0 0 0 12:55 122 122 122 70 0 0 0 0 13:00 122 122 70 25 0 0 0 0 13:05 122 70 25 0 0 0 0 0 13:10 70 25 0 0 0 0 0 0 13:15 25 25 0 0 0 0 0 0 13:20 25 25 0 0 0 0 0 0 13:25 25 25 0 0 0 0 0 0 13:30 25 25 0 0 0 0 0 0 13:35 25 25 0 0 0 0 0 0 13:40 25 25 0 0 0 0 0 0 13:45 25 25 0 0 0 0 0 0 13:50 25 25 0 0 0 0 0 0
Solar eclipse, 21st June 2020 likely impacts and Preparedness- A report Page 91 of 99
Northern region Hydro stations 5-minute schedule
Time Koldam Schedule (MW) Parbati-III Schedule (MW) 10:15 0 0 0 0 0 0 0 0 10:20 0 0 0 0 0 0 0 0 10:25 0 0 0 0 0 0 0 0 10:30 0 0 0 0 0 0 0 0 10:35 0 0 0 0 0 0 0 0 10:40 0 0 0 0 0 0 0 0 10:45 0 0 0 0 0 0 0 0 10:50 0 0 0 0 0 0 0 0 10:55 0 0 0 0 0 0 0 0 11:00 40 0 0 0 0 0 0 0 11:05 150 40 0 0 0 0 0 0 11:10 150 150 40 0 0 0 0 0 11:15 150 150 150 40 20 0 0 0 11:20 150 150 150 150 80 35 0 0 11:25 170 170 170 170 130 110 35 0 11:30 192 192 192 192 130 130 110 80 11:35 192 192 192 192 130 130 130 130 11:40 192 192 192 192 130 130 130 130 11:45 192 192 192 192 130 130 130 130 11:50 192 192 192 192 130 130 130 130 11:55 192 192 192 192 130 130 130 130 12:00 192 192 192 192 130 130 110 80 12:05 170 170 170 170 130 110 35 0 12:10 150 150 150 150 80 35 0 0 12:15 150 150 150 40 20 0 0 0 12:20 150 150 40 0 0 0 0 0 12:25 150 40 0 0 0 0 0 0 12:30 40 0 0 0 0 0 0 0 12:35 0 0 0 0 0 0 0 0 12:40 0 0 0 0 0 0 0 0 12:45 0 0 0 0 0 0 0 0 12:50 0 0 0 0 0 0 0 0 12:55 0 0 0 0 0 0 0 0 13:00 0 0 0 0 0 0 0 0 13:05 0 0 0 0 0 0 0 0 13:10 0 0 0 0 0 0 0 0 13:15 0 0 0 0 0 0 0 0 13:20 0 0 0 0 0 0 0 0 13:25 0 0 0 0 0 0 0 0 13:30 0 0 0 0 0 0 0 0 13:35 0 0 0 0 0 0 0 0 13:40 0 0 0 0 0 0 0 0 13:45 0 0 0 0 0 0 0 0 13:50 0 0 0 0 0 0 0 0
Solar eclipse, 21st June 2020 likely impacts and Preparedness- A report Page 92 of 99
Northern Region Hydro stations 5-minute schedule
Time Pong Schedule (MW) Bhakra-L&R Schedule (MW
10:15 0 0 0 0 0 0 0 0 0 0 10:20 30 0 0 0 0 0 0 0 0 0 10:25 30 30 0 0 0 0 0 0 0 0 10:30 30 30 30 0 0 0 0 0 0 0 10:35 30 30 30 30 0 0 0 0 0 0 10:40 30 30 30 30 30 0 0 0 0 0 10:45 30 30 30 30 30 30 0 0 0 0 10:50 66 30 30 30 30 30 0 0 0 0 10:55 66 66 30 30 30 30 0 0 0 0 11:00 66 66 66 30 30 30 0 0 0 0 11:05 66 66 66 66 30 30 0 0 0 0 11:10 66 66 66 66 66 30 0 0 0 0 11:15 66 66 66 66 66 66 0 0 0 0 11:20 66 66 66 66 66 66 0 0 0 0 11:25 66 66 66 66 66 66 0 0 0 0 11:30 66 66 66 66 66 66 0 0 0 0 11:35 66 66 66 66 66 66 70 115 20 0 11:40 66 66 66 66 66 66 126 140 115 70 11:45 66 66 66 66 66 66 126 156 156 115 11:50 66 66 66 66 66 66 126 140 115 70 11:55 66 66 66 66 66 66 70 115 20 0 12:00 66 66 66 66 66 66 0 0 0 0 12:05 66 66 66 66 66 66 0 0 0 0 12:10 66 66 66 66 66 66 0 0 0 0 12:15 66 66 66 66 66 66 0 0 0 0 12:20 66 66 66 66 66 30 0 0 0 0 12:25 66 66 66 66 30 30 0 0 0 0 12:30 66 66 66 30 30 30 0 0 0 0 12:35 66 66 30 30 30 30 0 0 0 0 12:40 66 30 30 30 30 30 0 0 0 0 12:45 30 30 30 30 30 30 0 0 0 0 12:50 30 30 30 30 30 0 0 0 0 0 12:55 30 30 30 30 0 0 0 0 0 0 13:00 30 30 30 0 0 0 0 0 0 0 13:05 30 30 0 0 0 0 0 0 0 0 13:10 30 0 0 0 0 0 0 0 0 0 13:15 0 0 0 0 0 0 0 0 0 0 13:20 0 0 0 0 0 0 0 0 0 0 13:25 0 0 0 0 0 0 0 0 0 0 13:30 0 0 0 0 0 0 0 0 0 0 13:35 0 0 0 0 0 0 0 0 0 0 13:40 0 0 0 0 0 0 0 0 0 0 13:45 0 0 0 0 0 0 0 0 0 0 13:50 0 0 0 0 0 0 0 0 0 0
Solar eclipse, 21st June 2020 likely impacts and Preparedness- A report Page 93 of 99
Northern region Hydro stations 5-minute schedule
Time Chamera-I Schedule (MW) Chamera-III Schedule
(MW) Total NR Hydro Schedule (MW)
10:15 0 0 0 0 0 0 25 10:20 0 0 0 0 0 0 125 10:25 0 0 0 0 0 0 277 10:30 0 0 0 7 0 0 436 10:35 18 0 0 20 7 0 601 10:40 90 18 0 20 7 7 780 10:45 90 90 18 40 40 20 966 10:50 150 90 90 77 40 20 1171 10:55 180 150 90 77 77 77 1391 11:00 180 180 150 77 77 77 1617 11:05 180 180 180 77 77 77 1853 11:10 180 180 180 77 77 77 2099 11:15 180 180 180 77 77 77 2355 11:20 180 180 180 77 77 77 2620 11:25 180 180 180 77 77 77 2890 11:30 180 180 180 77 77 77 3153 11:35 180 180 180 77 77 77 3428 11:40 180 180 180 77 77 77 3674 11:45 180 180 180 77 77 77 3776 11:50 180 180 180 77 77 77 3674 11:55 180 180 180 77 77 77 3428 12:00 180 180 180 77 77 77 3153 12:05 180 180 180 77 77 77 2890 12:10 180 180 180 77 77 77 2620 12:15 180 180 180 77 77 77 2355 12:20 180 180 180 77 77 77 2099 12:25 180 180 180 77 77 77 1853 12:30 180 180 150 77 77 77 1617 12:35 180 150 90 77 77 77 1391 12:40 150 90 90 77 40 20 1171 12:45 90 90 18 40 40 20 966 12:50 90 18 0 20 7 7 780 12:55 18 0 0 20 7 0 601 13:00 0 0 0 7 0 0 436 13:05 0 0 0 0 0 0 277 13:10 0 0 0 0 0 0 125 13:15 0 0 0 0 0 0 50 13:20 0 0 0 0 0 0 50 13:25 0 0 0 0 0 0 50 13:30 0 0 0 0 0 0 50 13:35 0 0 0 0 0 0 50 13:40 0 0 0 0 0 0 50 13:45 0 0 0 0 0 0 50 13:50 0 0 0 0 0 0 50
Solar eclipse, 21st June 2020 likely impacts and Preparedness- A report Page 94 of 99
Annexure- X
Hydro Generation in WR and Reservoir Level ISGS Hydro Generating Station-
Maharashtra State Hydro Generating Station-
Gujarat State Hydro Generating Station-
Solar eclipse, 21st June 2020 likely impacts and Preparedness- A report Page 95 of 99
Gujarat State Hydro Generating Station
MP State Hydro Generating Station
Solar eclipse, 21st June 2020 likely impacts and Preparedness- A report Page 96 of 99
MP State Hydro Generating Station
Solar eclipse, 21st June 2020 likely impacts and Preparedness- A report Page 97 of 99
Annexure- XI
Details of PPC installation at solar plants
Region Name of the Plant Installed Capacity
(MW)
PPC Status
SR
NTPC NP KUNTA 250 Yes
ACME BHIWADI 50 No
ACME HISSAR 50 No
ACME KARNAL 50 No
TATA 100 No
AZURE 50 No
FRV-I 50 No
FRV-II 50 No
WR
Acme Jaipur Solar Power Pvt. Ltd. 250 No
Arinsun Clean Energy Pvt. Ltd. 250 No
Mahindra Renewables Pvt. Ltd. 250 No
WELSPUN (Ratangarh (Neemuch) 105 Yes
M/s. Fermi Solar farms Pvt. Ltd. 80 Details not available
M/s. Fermi Solar farms Pvt. Ltd. 60 Details not available
M/s. Gale Solar farms Ltd (Saltek) 50 Details not available
M/s. Tornado Solar farms Ltd. (Saltek) 20 Details not available
JBM Solar Energy Maharashtra Pvt. Ltd. 100 Details not available
M/s. NVR Maha Solar Pvt. Ltd. 54 Details not available
M/s. Parampujya Solar Energy Pvt. Ltd. 20 Details not available
M/s. Osmanabad Solar Energy Ltd. 20 Details not available
M/s. Fourth Dimension Infra & Power Ltd 18.25 Details not available
M/s Tata Power Renewable Energy Ltd 55 Details not available
M/S Clean Sustainable Solar Energy Pvt. Ltd.
50.33 Details not available
MAHAGENCO 125 Details not available
M/s. Orange Renewable Power Pvt. Ltd.
100 Details not available
M/s. Solar Edge Power & Energy Pvt Ltd 130 Details not available
M/s. Talettutayi Solar Projects Four Pvt. Ltd
50 Details not available
Solar eclipse, 21st June 2020 likely impacts and Preparedness- A report Page 98 of 99
Details of PPC installation at solar plants
Region Name of the Plant Installed Capacity
(MW)
PPC Status
NR
Azure Power India Pvt. India Ltd. 200 Yes at Inverter level
Acme Chittorgarh Solar Energy Pvt. Ltd 250 Yes
Clean Solar Power (Bhadla) Pvt. Ltd 300 Yes
Renew Solar Power Pvt. Ltd. Bikaner 250 Yes
SB Energy Four Pvt. Ltd. 200 Yes
Mahoba Solar (Up) Private Ltd 250 Yes
Renew Solar Power Pvt. Ltd 50 Yes
Tata Power Renewable Energy Ltd. 150 Yes
Azure Power Thirty Four Private Ltd 130 Yes
Godawari Green Energy Ltd. 50 Yes
Yarrow Infrastructure Pvt. Ltd. 70 Yes at Inverter level
NTPC Ltd - Bhadla Solar Power Project 260 Yes
Solar eclipse, 21st June 2020 likely impacts and Preparedness- A report Page 99 of 99
Disclaimer
Precautions have been taken by Power System Operation Corporation (POSOCO) to ensure that
the accuracy of data / information in this report is accurate, reliable and complete. However,
before relying on the information from this report, users are advised to ensure its accuracy,
completeness and relevance for their purposes. POSOCO shall not be responsible for any errors
or omissions. All information is provided without warranty of any kind.
POSOCO disclaims all express, implied, and statutory warranties of any kind to user and/or any
third party, including warranties as to accuracy, timeliness, completeness, merchantability, or
fitness for any particular purpose. POSOCO have no liability in tort, contract, or otherwise to
user and/or third party. Further, POSOCO shall, under no circumstances, be liable to user,
and/or any third party, for any lost profits or lost opportunity, indirect, special, consequential,
incidental, or punitive damages whatsoever, even if POSOCO has been advised of the possibility
of such damages.
By reading this report, the users/reader confirm about their awareness and agreement to this
disclaimer and associated terms referred elsewhere.
Power System Operation Corporation Ltd.(A Government of India Enterprise)
Registered Office : B-9, Qutab Institutional Area,Katwaria Sarai, New Delhi - 110016
thANNULAR SOLAR ECLIPSE OF 26 DECEMBER 2019
stANNULAR SOLAR ECLIPSE OF 21 JUNE 2020