Comments on: Wind-turbine carbon payback times shorter than expected, finds new study https://www.windpowerengineering.com/wind-turbine-carbon-payback-times-shorter-than-expected-finds-new-study/ The technical resource for wind power profitability Mon, 31 May 2021 21:08:33 +0000 hourly 1 https://wordpress.org/?v=6.8.1 By: Keith Towse https://www.windpowerengineering.com/wind-turbine-carbon-payback-times-shorter-than-expected-finds-new-study/#comment-646254 Mon, 31 May 2021 21:08:33 +0000 http://www.windpowerengineering.com/?p=45656#comment-646254 Tom, sorry but your calculations are way off. A 1.5MW wind turbine operating at 35% capacity factor (typical of most installations in North America in the past decade) will give 1.5MW x 35% x 7860 hours = 4599 MWh per year – this is after allowing for losses, maintenance time etc. Very different to your 51MWh – if that were true, there wouldn’t be a single turbine installed! MIT says that there is around 750 lb of rare earth minerals in a wind turbine. Most recent studies say that wind turbines will offset the CO2 generated in their production and installation in around six months.

And wind is not subsidized any more. It is now the cheapest grid scale source of power, even according to an oil industry web site https://oilprice.com/Latest-Energy-News/World-News/Wind-Solar-Are-Now-The-Cheapest-Sources-Of-Power-Generation.html

]]> By: Tom https://www.windpowerengineering.com/wind-turbine-carbon-payback-times-shorter-than-expected-finds-new-study/#comment-645859 Tue, 25 May 2021 04:06:49 +0000 http://www.windpowerengineering.com/?p=45656#comment-645859 I really doubt it.
Just to let you know these are hand calcs on a napkin.
Totem contracting states that a 1.5MW turbine operating 24 hours a day for a whole year can generate 3285 MWh. That is usually at rated speed of 30-50mph winds. (Not realistic and you have to have down time for routine maintenance). They admit they usually deliver about 25% of capacity so forget the 25% for a moment. Now, for ever half of the wind speed you lose 8 times the generating capacity. So, a 40mph taken down to 20mph will get 410 MWh and a 10mph will get 51 MWh.
Columbia U has a calculation on how much energy it takes to make a ton of cement. It is 4.7M btu or 1.4 MWh. Each turbine requires 1200 tons of cement. That is from Northwest mining. So, 1200 tons of cement take 1680 MWh to produce.
Divide that by 51 MWh per year with no stops for maintenance or an unusually calm period of wind means the wind generator has to operate for 32 years to pay for the energy just for cement. That does not include mining iron ore, processing the iron ore with coal to make steel and fabrication of the steel. It does not include the 4.7 tons of copper and 3 tons of aluminum which have to go through the same processes.
Also ther are 2 tons of rare earth elements (mostly from China), zinc and molybdenum. Then you add the resins (from petrochemicals) that have to be processed and transported to the site.
Then add the end of life disposal. Many elements can be recycled but the blades cannot. Try googling wind generator blades landfill.
Even with Government subsidies, these things are decades away from breaking even. That goes with a carbon footprint as well.

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