Here is a summary of a more in-depth number-crunching about respective impacts of electricity produced with natural gas versus coal. The detailed rationale is here.
The above graph summarizes the results. In the green zone, electricity produced by gas has less total GHG emissions than coal, in red, it is worst.
- The generation of 1 MWh of electricity by a coal-fired power plant produces about 1 t of CO
- The generation of 1 MWh of electricity by a gas-fired power plant produces about 0.5 t of CO2
- For that reason, gas-generated power is perceived as greener than coal-generated power.
- Gas leakage occurs during the extraction, processing and transportation of the gas.
- One tonne of Methane, the main component of natural gas, has the same climate change impact than 72 t of CO2.
- The leakage rate of natural gas is 2.4 %, according to US EPA.
- At 2.4% leakage rate, the total GHG impact of 1MWh produced with gas increases to 0.84 t of CO2.eq
- At a 3.2% leakage rate, the total CO2.eq produced by both coal and gas fired plant are equal.
- The perception that the electricity generated by gas is cleaner than electricity produced by coal is misguided.
- Generating electricity with renewable energy instead of a gas turbine will displace near to 0.84 t of CO2.eq per MWh produced. (if leakage is only 2.4%)