Replacing Coal Power with Wind and Solar Increases Net CO2 Emissions
14 hours ago Guest Blogger 47 Comments
By Douglas Pollock
Advocates of wind and solar power confidently assert that using it to replace a coal-fired power plant will abate all the CO2 formerly emitted by the coal station, because unreliables do not emit CO2.
Not quite.
To keep the lights on when we need them, wind and solar requires backup from flexible sources, such as natural gas, that can react quickly when the Sun rises or sets, or when the wind drops or blows a gale.
This thermal backup emits CO2. Worse, when thermal stations are on standby, known in the trade as rotating reserve, they burn fuel without feeding any power to the grid and, when needed, they must be suddenly ramped up to full load capacity, thus emitting far more in the process than when running permanently at full load. Their emissions must thus be subtracted from the reductions achieved by decommissioned coal-fired capacity.
Why would anyone bother with wind and solar power? The fastest way to reduce grid emissions is to switch from coal-fired to gas-fired generation without using unreliables at all. That coal-to-gas switch cuts CO2 emissions by the difference between the products of the CO2 output emission rates and outputs of coal – a far greater reduction than that which is achieved by replacing coal with renewables backed up by thermal sources.
https://wattsupwiththat.com/2023/06/16/replacing-coal-power-with-wind-and-solar-increases-net-co2-emissions/
