How to calculate GHG emission for electricity consumption from the grid?

A large portion of Greenhouse Gas emissions (GHG) from most companies comprise of consumption of electricity from the grid. In India, around 65% of electricity is coming from coal and other fossil fuel based thermal power plants. Electricity generated from these power plants contributes in GHG emissions. Therefore, electricity being consumed from the grid also contributes in the GHG emissions.  GHG emission from the grid electricity consumption is categorized as energy indirect GHG emissions or scope 2 GHG emissions.

Sourcing renewable energy helps to minimize such emissions related to consumption of electricity from the grid. Electricity generated by renewable energy based power plant avoids consumption that would otherwise have been produced by power plants that would emit GHGs due to combustion of fossil fuels. This is also the basis for Clean Development Mechanism (CDM) supervised by the United Nation’s Framework Convention on Climate Change (UNFCCC).

The GHG emissions resulted from the generation of electricity is calculated as per the methodology developed by CDM – UNFCCC. In India, Central Electricity Authority (CEA), Government of India, prepares a database for GHG emission factor for the Indian grid annually.

The Indian electricity system is divided into two grids, the Integrated Northern, Eastern, Western, and North-Eastern regional grids (NEWNE) and the Southern Grid. Each grid covers several states. For each of the two grids, the main emission factors are calculated in accordance with the relevant CDM methodologies. CEA keep on updating the database at the end of each fiscal year. (Read more about Indian Power Grid System)

Following table shows the GHG emission factor for grid electricity;

Note: All the values are in tCO₂/MWh

From the above table, it can be observed that the GHG emission factor tend for the whole India has increased at the CAGR of ~3% every year. This indicates the increasing energy mix from fossil fuel based thermal power plants.

For calculation of GHG emissions from grid electricity consumption, following formula can be used;

GHG emission in tCO₂ = Electricity consumption (MWh)  X  GHG emission factor (tCO₂/MWh)

The database is an official publication of the Government of India. It is based on the most recent data available with the CEA. Therefore, it can be consider authentic and reliable.

Source link for CEA EF Database: http://www.cea.nic.in/reports/planning/cdm_co2/cdm_co2.htm