The energy payback for a 2-megawatt wind turbine that lasts over 20 years is... 5-8 months

2 Megawatt wind turbine construction
Public Domain Wikimedia

Talk about a great return on investment!

Some people who are against renewable energy - often when you follow the money you find that they are being financed by fossil fuel interests - spread all kinds of misinformation. One of their main arguments is that it takes so much energy to, for example, build wind turbines that the energy that is produced takes a long time to offset the energy used for production and installation, making them a worse deal than they seem, and thus not as beneficial to the environment as pro-renewable people claim.

It might sound like a good 'gotcha', but the facts don't back it up.

Wind TurbineWikipedia/CC BY-SA 2.0

The first thing to remember is that there's no such thing as a free lunch; building anything requires an upfront investment. Coal and natural gas power plants take a lot of energy to build too, and on top of that initial energy deficit, it also takes a lot of energy to mine coal or frack for natural gas, and then transport it in trains or pipelines, etc. With renewables, the wind and the sun are free, so after the production and installation, you're pretty much done for decades.

Nobody is arguing that fossil fuels are energy-negative on balance, because they aren't. But I just want to highlight that there's a double standard take place when a spotlight is put on the energy costs of producing renewable energy equipment but nobody mentions that the same thing is true for the fossil fuel industry.

Wind power turbines construction photoFlickr/CC BY 2.0

Back to wind power: A new study published in the International Journal of Sustainable Manufacturing looks at the cumulative energy payback of 2-megawatt wind turbines that are used in the Pacific Northwest, precisely calculating the lifecycle energy required for manufacturing, installation, maintenance, and turbine end-of-life processing, and looking at how that stacks up against energy production over the life of the turbines (a working life of 20 years or more is not unusual).

The researchers found that the vast majority of the environmental impact comes from the materials used and the manufacturing processes. This is interesting, because it means that by running turbine plants on renewable energy, the impact could be lowered significantly. Same with how the materials are produced. It's a virtuous cycle because the more wind and solar we have on the power grid, the cleaner the energy that is used for manufacturing becomes...

The payback for the associated energy use is within about 5-8 months, and even in the worst case scenario, lifetime energy requirements for each turbine only takes 1 year of operation. So for the next 19 years, each turbine will, in effect, power over 500 households without consuming electricity generated using conventional energy sources, and if the turbines end up operating for over 20 years, that's just a bonus.

Wind turbine constructionFlickr/CC BY-ND 2.0

Via Science Daily

Tags: Renewable Energy | Wind Power


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