The carbon footprint of a product or service is the quantity of CO2 and other greenhouse gas emissions that it releases into the atmosphere over its entire life cycle. Carbon footprints are usually calculated using a method known as Life Cycle Assessment (LCA) and are measured in gCO2eq/kWh. These CO2 emissions can either be direct-arising during the operation of the power plant or indirect-arising during other non-operational phases of the plant or both.
Electricity generation technologies that are fueled by fossil fuels (coal, oil, and gas) tend to have the largest carbon footprints because they burn fuel through their operation. Out of these, conventional coal combustion systems have the largest carbon footprint of all electricity generation systems of the order of 1000 gCO2eq/kWh and form 73% of the total CO2 emissions from electricity generation. Oil combustion plants come in second with an average carbon footprint of approximately 650 gCO2eq/kWh followed by gas-powered plants that have a carbon footprint of around 500 CO2eq/kWh.
Currently, 42.5% of global CO2 emissions are emitted from electricity generation. This startling figure is only going to increase as studies predict that electricity generation requirement in the world could double by 2040. With population growth and economic development, electricity needs have soared. China is the world’s largest generator of electricity (24% of global output) followed by the USA (18.3%), India (5.1%), Russia (4.5%), and Japan (4.5%).
Current trends show us that global power generation is increasing at a rate of 2.2% per year. India and China, in particular, are forecast to step up their power generation by 261% and 177% respectively by 2030. These figures show us that electricity is an essential commodity and that we will now have to look at alternate low-carbon forms of generation like renewable and nuclear energy. Electricity generated from renewable sources have a much smaller impact on the environment and are practically unlimited. This is precisely why renewable energy must play an increasing role in the generation mix.
Technological improvements to existing coal-fired plants can also increase energy efficiency from 35% to 50%. This can halve the life cycle carbon emissions in both coal and gas-fired plants. Co-firing biomass alongside fossil fuels in existing power plants can also remarkably lower their carbon emissions, as the fossil fuels will be replaced by the carbon-neutral biomass. Alongside these improvements, Carbon Capture and Storage (CCS) can also play an essential role in stabilizing atmospheric greenhouse gas emissions. CCS could possibly avoid almost 90% of CO2 emissions to the atmosphere in the future. Using less raw materials to power these coal-fired plants can also help lower their life cycle CO2 emissions.
Low-carbon electricity generation technologies like biomass, photovoltaics (PV), hydro, wind, and nuclear energy having low carbon footprints (<100 gCO2eq/kWh), will soon fuel the decrease in carbon footprints of all electricity generation technologies. And if the manufacturing phase and other phases of the coal-fired plants are fueled by these low-carbon sources, we will be able to drastically decrease their carbon footprints. Further progress must be made to better the efficiency of these low-carbon sources as current renewables are less efficient and cost more than other forms of generation and therefore require government subsidies to be able to compete with their coal-fired counterparts. However, with an increased interest in the renewable sector and better policies by the government, it is only a matter of time before renewables completely phase out fossil fuels for power generation completely.
To better understand the global carbon footprint of electricity generation, read the whole report here!