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Finishline42

(1,161 posts)
Mon Nov 30, 2020, 08:14 AM Nov 2020

Replacing A Coal Plant Takes An Infinite Number Of Wind Turbines

Hate to spoil the article but this is why it takes an infinite number of windmills...

Coal generation also produces 84 kg of coal ash per MWh, so that coal plant produces about 265,000 tons of it a year. Wind generation doesn’t produce any coal ash, or indeed anything like it, so an infinite number of wind turbines would be required.

From the start...

Coal is going away. What will it take to replace all of the things it provides us with? An infinite number of wind turbines would be required to replace everything a coal plant gives us.

If it was just the electricity, only 120 to 350 modern wind turbines would be required, but that’s just the start.

These are averages and capacity factor-based. It’s an approximation. Capacity factor is the percentage of a year’s potential maximum generation that is actually achieved. If a generation unit could generate 100 MWh but actually generates 70 MWh — that’s a capacity factor of 70%. It’s based on a demand, market conditions, supply, maintenance, and the like.


As coal plants are shutting down, they’ve also been dropping in capacity factor, and now have an average of under 50%. We’ll use 50% as our capacity factor for coal.

In 2016, there were 381 coal plants with just under 800 generating units. The average coal plant was running around 720 MW of capacity. We’ll use 720 MW of capacity for coal as the basis.

720 MW of capacity running 24/7/365 with a capacity factor of 50% would generate about 3.15 TWh of electricity in a year.

The average capacity factor for modern wind turbines in the US is 41.9%. The average size of new wind turbines in the USA is 2.43 MW in capacity.

The first question is how many wind turbines would be required to generated 3.15 TWh of electricity.

3.15 TWh divided by 2.43 MW capacity divided by 24 hours divided by 365 days divided by a capacity factor of 41.9% gives us about 353 wind turbines.

So the first answer is that just over 350 wind turbines are required to replace a coal generation plant which likely has 2–3 generating units. That means that about 120–175 wind turbines are required to replace a single generating unit.

So far, so good. But coal plants do more than provide electricity. What else do they provide, and can wind turbines provide that too?


edited to add link to article - https://cleantechnica.com/2020/11/27/replacing-a-coal-plant-takes-an-infinite-number-of-wind-turbines/

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Replacing A Coal Plant Takes An Infinite Number Of Wind Turbines (Original Post) Finishline42 Nov 2020 OP
Had me worried for a second! Laf.La.Dem. Nov 2020 #1
Me as well initially Finishline42 Nov 2020 #3
The reference to Poe's Law at the end is obligatory Hokie Nov 2020 #2
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