A hypothetical estimation of
emission reductions in a
biomass power plant project
Dr. Oscar Coto
II National CDM Workshop
Belize
August 2011
General description of the
project
• Electricity generation using rice husk that
otherwise would have been burned in open
sky non controlled combustion.
• Construction and operation of a new 20 MW
with an energy conversion efficiency of 30%.
• Plant is scheduled to enter into operation on
January 1st 2012.
• Estimated electricity generation of 147,627
MWh/year equivalent to 531 TJ/year.
• Rice husk has a calorific value of 0.013
TJ/ton rice husk.
• Area of influence of the project produces
around 0.9 million tons of rice husk per year
and only 0.3 million tons are currently used
for other uses in the area.
• Boilers are going to be using supplemental
fuel oil at a rate of 6 m3 per start of the
boilers during an estimated 5 times a year.
• It is estimated that 15 ton diesel operated trucks are
going to movilize the rice husk on trips that will
average 120 km round trip for each trip.
Basic data
• Emission factor of the electricity grid is 0,5 t CO2/MWh.
• Emission factor of the diesel trucks transporting the rice
husk is 0,001097 t CO2/km.
• Density of fuel oil is 890 kg/m3.
• Calorific value of the fuel oil is 0,0402 TJ/t.
• The CO2 content of the fuel oil is 75,96 t CO2/ TJ
• GWP of methane is 21 times that of CO2.
• TJ represents 1012 J
Some basic questions to
answer
• Quantity of energy to be supplied by the
rice husk to the boilers in TJ/year?
• Amount of rice husk that will need to be
supplied to the power plant in tons?
• Fraction of the available rice husk
available in the area that will be used by
the project?
• Make a diagram of the boundaries of
the project?
• Which types of sources and types of
greenhouse gases should be
considered for the purpose of emission
reduction estimates?
•
•
•
•
Estimate emissions of the baseline?
Estimate project emissions?
Estimate leakage emissions?
Estimate emissions reduction on a per
year basis?
• If the crediting period is 10 years under
the CDM what is the expected total
emissions reductions for the project?
1. Quantity of energy to be
supplied by the rice husk to
the boilers in TJ/year?
• 531 TJ-year/0.3 = 1,770 TJ/year of
energy in the rice husk to be supplied to
the power plant.
2. Amount of rice husk that
will need to be supplied to the
power plant in tons
• Amount of energy supplied by rice husk
/ calorific value of the rice husk
• 1,770 TJ/ year x 1/0.013 TJ/ton
• 136,153 tons of rice husk
3. Fraction of the available
rice husk in the area that will
be used by the project?
• Available biomass in the area = 0.9 million
ton (produced) – 0.3 million tons (currently
being used by other users) = 0.6 millions tons
rice husk available
• Fraction = 136,153 tons / 600,000
• Fraction = 22.69% meaning that …
4. Make a diagram of the
boundaries of the project
5. Which types of sources and
types of greenhouse gases should
be considered for the purpose of
emission reduction estimates?
• Baseline: grid emissions
• Project: combustion of diesel oil in the
transportation trucks, combustion of fuel oil
during boiler start ups
• Leakage: please discuss?
• Which are the types of GHG involved in each
of the sources?
6. Estimate emissions of the
baseline?
• BLE= Electricity generated x grid emission
factor
• BLE = 146,627 MWh/year x 0.5 ton
CO2/MWh
• BLE = 73.313 ton CO2/year
7. Estimate project
emissions?
• Transportation
• PET = Amount of km travelled by trucks x fuel
emission factor of the combustion of diesel in
those trucks
• Amount of km travelled = tons of biomass to
be moved / truck capacity x average travel
distance per round trip
• Amount of Km travelled = 136,153 / 15 x 120
• Amount of km travelled = 1,089,224 km
• PET = 1,089,224 km x 0,001097 t
CO2/km
• PET = 1,194.8 ton CO2/year
• Auxiliary fuel oil use
• PEAF = Amount of fuel oil used per
year x emission factor of the
combustion of fuel oil
• Amount of fuel oil used = 6 m3 x 5 = 30 m3 of
fuel oil per year
• Amount of fuel oil = 30 m3 x 890 kg/m3 /
1000 = 26.7 tons of fuel oil/year
• Equivalent to 26.7 tons x 0.0402 TJ/ton =
1.07 TJ/year
• PEAF = 1.07 TJ /year x 75.96 ton CO2 /TJ
• PEAF = 81.27 ton CO2/year
• Project Emissions (PE)
• PE = PET + PEAF
• PE = 1,194.8 ton CO2/year + 81.27 ton
CO2/year
• PE = 1.276 ton CO2 / year
8. Estimate leakage
emissions?
• LE = ?
•0
9. Estimate emissions
reduction on a per year basis?
Emissions reductions (ER) =
Baseline emissions (BLE) –
Project emissions (PE) –
Leakage emissions (LE)
• ER = 73,313 tons CO2/year – 1.276 ton
CO2/year – 0
• ER = 72,037 ton CO2/year
• Over 10 years would amount to
720,370 tons CO2