Are wind turbines hiding CO2 emissions?

I was asked this question by a client today and didn't know the answer, but resolved to find out.

On the face of it, wind turbines are carbon neutral, the wind is free when it blows and no fuel is used, so no emissions. But what about building and siting them? Wind turbines are made of steel, sunk into a concrete base, with blades manufactured from carbon fibre & aluminium, and huge magnets inside, made from some pretty exotic materials, and all of that has an impact on the environment.

The good news is that, according to Bernstein Research, wind turbines produce on average 11g of CO2 for every kilowatt-hour of electricity (when you amortise the CO2 across their decades long life span), compared to 44g for solar, a whopping 450g for gas, and 1,000g for coal. Bigger turbines are getting even more efficient, some as low as 6g.

Interestingly, nuclear generation produces 9g of CO2 per kilowatt-hour, with the vast majority of that associated with building the facility, much like wind turbines.

So, there is an environmental impact for wind turbines but, aside from nuclear, that impact is comparatively low. Turbines and blades need replacing over time, but much of the material is recycled. Combining the environmental impact with the cost of producing electricity, at around 9 times cheaper than a gas, there's a good argument for wind turbines being a big part of our energy future.

Finally, there have been reports of average wind speeds reducing over time, ironically driven by climate change. The IPCC latest report suggests that average wind speeds will reduce by 8%-10% as a result of climate change, but other climate models suggest wind speeds will increase. Even if this reduction happens, wind turbines will remain the cheapest and most environmentally friendly way to produce electricity for many years to come.

(Image by raw pixel.com on Freepik)