unep rise centre - demark fourth regional workshop and training on “capacity development for the...
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UNEP rise centre - DemarkFourth regional workshop and training on
“Capacity development for the clean development mechanism”4-6 April - AIT Thailand
Report, Case study 2
Study baseline methodology in Vietnam comments and proposal
By Dr. Bui Huy Phung
Dr. Nguyen Tien Nguyen
VN CD for CDM
Key contents
Part I. Study to build the typical baseline for Vietnam electrical grid
1.1. Methodology
1.2. Data needed
1.3. Result of typical baseline calculation for Vietnam electricity grid
Part II. Comments and proposal.
2.1. Comments
2.2. Proposals used.
Part I. Study to build the typical baseline for Vietnam electrical grid
1.1. Methodology
There are 2 specific guides issued by EB to calculate baseline emission factor for the grid.
• Appendix B of the simplified modalities and procedures for small-scale CDM project activities
• Consolidated baseline methodology for grid connected electricity generation from renewable sources
Following quanlities must be calculated:
- The operating margin emission factor (EF-OM)
- The build margin emission factor (EFBM)
- The baseline emission factor EF.
1.1. Methodology (cont.)
a. Based on guiders of appendix B, following calculation formular are used
• EF-OM (t CO2eq/kWh)= Ej/ Gj
Ej is CO2 emission per year in tons for fuel j- tCO2/year
Gj: electricity generation from fuel j
• EF-BM (tCO2eq/kWh)= EFy.GENi / GENi
EFi- the emission rate for unit i (tCO2/kWh)
GENi - the generation (kWh) from unit i.
• Calculate 1/2(EFOM + EFBM)
• Calculate GA-weighted average emission of all power plants (grid average)
GA= Ej / GENj
1.1. Methodology (cont.)
b) Based on consolidated baseline methodology• Calculate the operating margin emission factor (EFOMy)
+ Simple OM, EFOM simp. y - the generation weighted average emission per electricity unit of all generating sources serving in the system
EFOM,y=Fi,j y*COEFij / GENj,y
Fi,j,y- the mass of fuel i consumed by sources j in year y
+ Simple adjusted OM
In this case, power sources include imports and are separated in low cost /must-run power plants.
b) Based on consolidated baseline methodology (cont.)
+ Dispatch data analysis OM
EFOM,Disp j = EOMy/EGyIn which
EGy - generation of project in year y (kWh, MWh)EOMy = EGh*EFDDh
EGh - the generation in each hour h, and
EFDDh - the hourly generation weighted average emission per electricity unit of the set of power plants (n) in the top 10% of grid dispatch order during hour h.
+ Average OM aver
EFOM-aver is calculated as the average emission rate of all power plants, using equation described for the simple OM above, but including low-operating cost and must-run power plants.
1.1. Methodology (cont.)
c) The build margin emission factor
Calculate EFBM,y as the generation weighted average emission factor of power plants (m)
d) Calculate the baseline emission factor EFy
EFy = WOMEFOMy + WBMEFBMy
When using this methodology there are a lot of difficulties
• It is short of day-night typical load diagram of grid in dry season and rainy season, (or typical day of year) specially for future
• Dispatch data is not available so it can not to analyze OM
• It is complicated to identify low cost/must run power sources, specially for future
• Etc.
So it is not able to calculate EFOM as requested conditions.
im m
ymimimjyBM GENCOEFFEF ,, /*
1.2. Needed key data
• COEFj - CO2 emission per unite for each fuel j
• LHVj - low heat value of fuel j
• GENj - electricity generation from fuel j (kWh. MWh,…)
• 5 most recent plants and their performances
• Or the most recent 20% of existing plants and their performances
• Forecasted data of power plants and grid in study periods
• etc
1.3. Result of typical baseline calculation for Vietnam electricity grid
a) Based on appendix BTable 1: Baseline emission factors of the Vietnam national
grid, gCO2/kWh
End of year
2001 2002 2003 2004 2005 2006 2007 2008 2009 2010
GA 358.9 403.8 384.1 387.6 404.5 394.9 416.1 416.8 425.6 425.2
OM 884.7 780.4 728.0 630.5 617.8 585.3 612.7 613.5 632.6 640.6
BM 313.5 478.1 562.2 601.2 492.9 418.6 401.3 535.7 496.3 420.7
½ OM
+ ½ BM
599.1 629.2 645.1 615.8 555.4 501.9 507.0 574.6 564.5 530.7
Figure 1. emission factors of the Vietnam national grid during period of 2001-2010
300
400
500
600
700
800
900
2001 2002 2003 2004 2005 2006 2007 2008 2009 2010Year
gCO
2/kW
h GA
OM
BM
½ OM+½ BM
b) In case of consolidated baseline methodologyAccording to Simple OM
Table 2: Baseline emission factor calculated in OMsimple, gCO2/kWh
End of year
2001 2002 2003 2004 2005 2006 2007 2008 2009 2010
Most recent 3-year average
- - 680.0 657.1 575.9 514.9 503.3 569.8 558.0 524.8
Commis-sioning year
599.1 629.3 645.1 615.9 555.4 502.0 507.0 574.6 564.5 530.7
Figure 2: Baseline emission factor calculated in Simple OM
0
100
200
300
400
500
600
700
800
900
2001 2002 2003 2004 2005 2006 2007 2008 2009 2010
Year
gCO
2/kW
h
OM3year
Omhd
BM
1/2OM3year+1/2BM
1/2OMhd+1/2BM
Table 3: Baseline emission factor calculated in OMaverage,
gCO2/kWh
End of year
2001 2002 2003 2004 2005 2006 2007 2008 2009 2010
Most recent 3-year average
- - 472.3 496.5 442.5 407.2 403.2 472.5 457.9 421.6
Commis-sioning year
336.2 441.0 473.2 494.4 448.7 406.8 408.7 476.3 461.0 423.0
Figure 3: Baseline emission factor calculated in Average OM
Part II. Comments and proposals
2.1. CommentsBased on using methodologies and calculation, we can conclude as following:– Two specific guiders issued by EB to calculate baseline emission
factor are interesting, conservative, that help developers to calculate baseline in their condition.
– Baseline emission factors calculated in different options or methodologies will be different. So depending on specific project, applicable conditions, project developers can select an suitable baseline emission factor.
In Vietnam case study :– Emission factors of power plants using different fuels are different
+ Using coal coming down from 1.5 kgCO2/kWh to 1.0 kgCO2/kWh by 2010 year ;+ Using oil is about 0.9 kgCO2/kWh ;+ Using gas is about 0.45 kgCO2/kWh
– Average emission factor of system (1/2OM+1/2BM) having a decreased trend and varying from 0.5 to 0.6 kgCO2/kWh.
2.1. Comments (cont.)
• Based on OM curves, it is seen that the baseline emission factors decrease strongly because of increasing thermal plants efficiency and more gas-fired plants built. But since 2006, mainly coal-fired plants will be built, so the factors will be lightly increased.
• Since 2002, more thermal power plants are built, this is described on the BM curves, but since 2006, hydropower plants will be relatively large built, so the BM factor will decrease.
• However, curves of average OM and BM as well as GA curves are relatively stable.
2.2. Used proposals
a) Project registered in 2005, started operating in 2008, with crediting of 10 years
• Small-scale project: select the table 1 above, at column of year of 2005, can choose emission factors of ½ OM+ ½ BM (555.4 gCO 2/kWh).
• Large scale project:
+ If total 5 years average hydropower output generated is less than 50% of total electricity output generated of the grid, table 2 will be selected. Then there are 2 emission factors: if based on the most recent statistics available at the time of Project Design Document (PDD) submission then 3 years average emission factor will be used, column of year of 2005 will be chosen (575.9 gCO2/kWh); if based on commissioning year then column of
year of 2008 will be chosen (574.6 gCO2/kWh).
+ Or if total 5 years average hydropower output generated is more than 50% of total electricity output generated of the grid, table 3 will be selected. Then there are 2 emission factors: if based on the most recent statistics available at the time of PDD submission then 3 years average emission factor will be used, column of year of 2005 will be chosen (442.5 gCO2/kWh); if based on commissioning year then column of year
of 2008 will be chosen (476.3 gCO 2/kWh).
This emission factor will used for project emission reduction calculation for whole 10 year crediting period.
b) Project with crediting of 7 years registered in 2005, started operating in 2008: is similar to for crediting of 10 years above, the difference is the emission factor only used in 7 years, if it is continued in more 7 years, the emission factor will has to be re-calculated. Then the new factor may be different from the old one because of data changes.
2.2. Used proposals (cont.)
