CALCULATING GRID EMISSION FACTOR

http://girishshivakumar.wordpress.com/ Girish Shivakumar

On Emissions from Power Plants:

Power Generation (MWh)

Emission Factor (Tons CO2/MWh)

X=CO2 Emissions (tons CO2)

=

X

44g/moleCO2

12g/moleCX1 ton C

1 kgC

TJvol unit of fuel Xkg

CTJ

Xvol fuel consumed

Mwh output

conversion factors

Plant based- actual data

Carbon emission factor, per fuel type - IPCC

Net calorific value, country specific, per fuel type - IPCC

Emission Factor (Tons CO2/kWh)

GHG = EFP X

EMISSION FACTOR

Emission factor for a country/region depends on the energy mix in the country/region

METHODS TO CALCULATE THE GRID EMISSION FACTOR

As per the Clean Development Mechanism (CDM) there are 4 ways to calculate the CO2 emissions Weighted average Simple operating margin Build Margin Combined Margin

METHODS TO CALCULATE THE GRID EMISSION FACTOR

Weighted average The weighted average emission factor describes the

average CO2 emitted per unit of electricity generated in the grid. It is calculated by dividing the absolute CO2 emissions of all power stations in the region by the region’s total net generation.

Simple operating margin The operating margin describes the average CO2

intensity of the existing stations in the grid which are most likely to reduce their output if a CDM project supplies electricity to the grid. The energy mix excludes low-cost power like hydro and renewable energy.

METHODS TO CALCULATE THE GRID EMISSION FACTOR

Build Margin Build margin is the grid mix of recent capacity additions

(newly installed plants) defined as lower of most recent 20% of plants built or the 5 most recently built plants.

Combined Margin The combined margin is a weighted average of the

simple operating margin and the build margin. By default, both margins have equal weights (50%).

A TYPICAL EXAMPLE

Consider a project case of 5MW of hydro power project in Assam in the North Eastern Region of India with an estimated annual generation of 17,500MWh.

What is the emission reduction in the grid by this project?

For this we will have to look at the latest grid emission factor for India

INDIAN GRID EMISSION FACTOR

According to the Indian Electricity Authority’s report of 2014 the grid emission factors for India for 2012-13 are as

A TYPICAL EXAMPLE CONTINUED

Consider that factor, Assam located in NE grid has a GEF of 0.82t CO2/MWh. Hence the absolute savings for the Hydro project in Assam is 0.82*17,500= 14,350 t CO2/yr

CALCULATING GRID EMISSION FACTOR

http://girishshivakumar.wordpress.com/

Girish Shivakumar