Storage Applications in the Italian Transmission Grid to
facilitate RES integration
Rome, June 13th 2012
Angelo Ferrante
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Owner of more than 98% of the Italian EHV-HV Transmission Grid:
Over 63.578 km of EHV and HV lines
11.261 km of 380 kV lines, 1.122 km of land and 917 km of submarine cables, Over 445 substations 122 GVA transforming capacity 22 interconnectors
France (4+1), Switzerland (9), Austria (1), Slovenia (2), Greece (1)
Responsible for planning, development, operation and maintenance of the NTG, as well as for the transmission and dispatching activities
332 TWh: energy demand in 2011 ( +0,6% vs 2010)
Peak demand: 56.5 GW (13 July 2011)
1st fully unbundled SO in Europe and 7th in the world
Francia 380 Venaus-‐Villarodin
Francia 380 Albertville-‐Rondissone
Francia 380 Albertville-‐Rondissone
Francia 220 Camporosso-‐Brioccarros
Svizzera 380 Musignano-‐Lavorgo
Svizzera 380 Bulciago-‐Soazza
Svizzera 380 Gorlago-‐Robbia
Svizzera 380 Sfiorano-‐Robbia
Svizzera 220 Avise-‐Riddes
Svizzera 220 Mese-‐Gorduno
Svizzera 220 Valpelline-‐Riddes
Svizzera 220 Pallanzeno-‐Serra
Svizzera 220 Ponte-‐Airolo
Austria 220 Soverzene-‐Lienz
Slovenia 380 Redipuglia-‐Divacca
Slovenia 220 Soverzene-‐Lienz
Terna and the Italian EHV-HV Transmission Grid Facts and figures
Angelo Ferrante - 13 June, 2012
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The TERNA Group Updated Group structure
Subsidiaries Joint ventures
Associates Companies evaluated using the equity method
Angelo Ferrante - 13 June, 2012
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Ownership structure Share capital divided according to reference areas
Updated as of April, 2012
Angelo Ferrante - 13 June, 2012
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Development Trend of RES Power Capacity in Italy (MW)
Italian Government targets:
23.000 MW (IV Conto energia) 12.700 MW (target PAN 2020) (*) December 2011 provisional data
*
Installed Capacity from Wind and Solar Power Plants
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Evolution of the generation scenario Development of the renewable energy generation capacity* (MW)
• Short-medium term forecasts • Installed wind and PV power
(*) Provisional data – December 2011
Angelo Ferrante - 13 June, 2012
PV
Wind Wind
PV
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Impact of fluctuating RES generation on power system
Main impacts
• Power Flow inversion in 150/20 kV distribution substations and local HV grid congestions
• Increase of congestions on 400 kV network in daily off peak conditions
• Balancing of generation surplus in very low load condition
• Security issues (frequency stability, lack of primary reserve, evening ramps)
Further impacts expected in the short-medium term horizon
• Extension of network congestions to further grid portions in South Italy
• National and zonal (South Italy and Sicily) Over-Generation that cannot be balanced
Current difficulties and possible envisaged problems
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Impact of fluctuating RES generation on power system Power Flow inversion
325 (9%)
543* (17%) 252
(7%)
358* (11%)
Annual data – 2011 vs. 2010
(*) provisional data – end 2011 / Source: ENEL Distribuzione
Total HV/MV sections in Italy Inversion >1% (>87 h/ year)
Inversion >5% (>438 h/ year)
Angelo Ferrante - 13 June, 2012
150 kV
20 kV
HV transmission grid
MV distribuMon grid
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SE 380/150 kV
Surplus of installed RES vs load + energy transfer capacity
Grounds for limiting the production of intermittent RES:
Solve local grid congestions
Security of the 150kV grid
Compliance with reserve requirements for secure operation of insular grids
Angelo Ferrante - 13 June, 2012
Impact of fluctuating RES generation on power system Local HV grid congestions
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Impact of intermittent RES on reserve and balancing
Primary reserve
The increase of intermittent RES implies an equivalent reduction of the conventional generation required for providing primary reserve
Secondary reserve/ Tertiary reserve
The power produced by intermittent RES determines a further level of uncertainty for real-time balancing of production and load
The increase of intermittent RES generation increases reserve needs but, at the same time,
reduces reserve availability
Risks for lack of regulating capacity margins
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D1 D2 D3
Risks of modulaEng RES generaEon
PV generation
Minimum Import
Not dispatchable generation
Minimum Thermal capacity necessary for system security
Load
Load – PV – Not predictable RES
• Constraints on use of regulaEng plants
• Maximize use of exisEng hydro-‐pumping power plants
• Import reducEon • Massive use of defense
systems
Impact on System Reserve and Power Balancing Effects of Huge Amount of RES on Generation Dispatching
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Limit (transmission capacity)
Curtailed intermittent energy
Curtailment reduction (storage)
Energy from ESS
Stored intermittent energy
Relieving congesEons Effect of storage devices on a congested line
Dispatched Intermittent production
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Law Decisions on Electricity Storage
Dlgs 3 march 2011, n. 28
• projects of new electricity storage plants aimed at supporting RES integration • projects included in the TNDP • Regulator provides for remuneration of investments
Dlgs 1 June 2011 , n. 93
• Terna and Distributors can build and operate storage plants with batteries • hydro-pumping power plants included in the TNDP are awarded by competitive procedures.
Delib. ARG/elt 199/11, 29.12.2011
• I3 incentives (ΔWACC: 2% 12yrs) for investments allowing to: • reduce congestions between market zones; • increase Net Transfer Capacity (NTC); • reduce intrazonal congestions, subject to approval of AEEG
• I4 incentives (ΔWACC: 2% 12yrs) for pilot projects on ESS (TSO and DSOs)
Planning, Realization and operation of electricity storage devices
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Analysis of the technical solutions Typical capacity values vs discharging time*
Angelo Ferrante - 13 June, 2012
* Electricity Storage AssociaMon (November 2008/ Ref. to installed devices )
Focusing on energy intensive and flexible soluMons, to be developed within next 2 years
InvesMgaMng technical soluMons able to take advantage of exisMng substaMons in order to reduce environmental impact and permiZng Mmes
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Advantages of Batteries
Installation of batteries vs BAU (grid development as the only solution)
• Congestion reduction
• Primary reserve
• Tertiary reserve
• Limited implementation time
• Modular, capillary and removable
• Limited impact on the territory
Underutilization of the grid (<10%)
Only if available in neighbouring area
Batteries BAU
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GWh/a *
Expected results Avoid curtailment of about 230 GWh/yr from RES Provide additional tertiary reserve on the market for
approximately 410 GWh/yr
FIRST STEP (130 MW)
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Recovered energy assessment
SECOND STEP (+110 MW)
ESS sizing
Expected results Avoid curtailment of about 440 GWh/yr from RES Provide additional tertiary reserve on the market for
approximately 750 GWh/yr
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The following overall benefits should be assessed:
• Reductions in the cost of energy:
Storage of RES energy when the grid is congested and then possible release of the energy stored,
replacing equivalent conventional thermal energy
• Increase of the adequacy/security margins:
• Meet the increased needs for secondary and tertiary reserves.
• Compensation of the frequency regulation capacity reduction of the system frequency/power
adjustments.
• Reduced costs for new HV lines and increased voltage regulation capacity
A
B
C
D
Benefits evaluation
Angelo Ferrante - 13 June, 2012
Benefits for the system Energy: reduced curtailment A Security: secondary– tertiary reserve B Security: primary regulation C Security: reduced costs for new HV lines D
Performance index
(A+B+C) NPV benefits
CapEx - D =
18
7
53
8
21
60 Avoiding to cut RES Energy
Secondary and terEary reserve resources for system balancing
Primary reserve resources for system security
Benefits Mln€/year*
Costs Mln€/year*
* Actualized benefits and costs in the lifeMme horizon of 15 years
PI = Benefit/Cost raEo > 1,8
Ba_eries CAPEX + OPEX
Benefit /Cost ratio of a 240 MW batteries investment
Avoid Network investments
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Strategies for integration of RES into the national power system
Investments planned by Terna for a stronger smart transmission system
• More than 2,5 Billion € within next 5 years to develop transmission network infrastructures distributed storage devices
Energy Policy Makers to be aware:
• Embedded generation to be compliant ASAP with grid requirements
• Fluctuating RES (esp. on MV and LV side) to improve their production forecast and to make available system regulation services
• Review market rules to realize more efficient price signals effective markets coupling
Conclusions
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Thank you for your
attention!