There are many arguments put forward to show that wind turbines do not reduce carbon emissions. I plan to write a lengthy piece at The Energy Collective at some point explaining the flaws in these arguments. But there is one I feel like debunking now.
Here is how it goes.
Each gigawatt of wind power must be backed up by 1 GW of relatively inefficient OCGT gas power plants. Wind turbines however only run with around 25% capacity factors. Therefore you need to run the OCGT power plants at 75% capacity factors.
In CO2 terms this is a bad idea, and no better than just getting your electricity from CCGT power plants. OCGT plants give you 0.6 tonnes of CO2 per MWh, whereas CCGT plants give you 0.4 tonnes of CO2. So wind backed up with OCGT will give you (0.75*0.6)/(0.4) = 1.125 times more CO2 than a purely CCGT set up.
Wind farms then provide more than 10% more CO2 than you would get if you just stuck with gas! Why bother?
Well, the logic above sounds persuasive and probably would persuade the average person with a prejudice against wind turbines. It is also total nonsense.
There are many engineering reasons why it is nonsense. I could go into them, but it can be refuted a little more simply.
The UK now has over 10 GW of wind power. By the above logic it therefore requires at least 10 GW of OCGT power plants to provide back up to these wind farms. If it does not then the arguments are complete piffle.
Thankfully the UK government provides us with a full list of power plants in Britain. So we can easily check how much OCGT is available to back up wind farms.
Instead of 10 GW of OCGT the UK has a total of 1.3 GW of OCGT. Not exactly an insignificant discrepancy.
Currently the UK has almost 11 GW of wind capacity, but only 1.3 GW of OCGT to back it up. And I can find absolutely no evidence of efforts to procure significant amounts of OCGT to back up wind farms. The argument then is bunk.
But these myths persist, and may go one persisting.