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  • Shawn Grannell commented on Short story Short story 1 week ago
    Shawn Grannell
    • Shawn Grannell Shawn Grannell 963 MW ~ 1 GW average power is yielded for 11 GW of installed nameplate capacity of all of the wind turbines in Texas. Now we have an answer for 'How many wind turbines will it take to equal the performance and economics of one nuclear power plant?' It's all the wind turbines in Texas. But that's just for average power. Any finite collection of wind turbines will sometimes have an output of zero. The number of wind turbines it takes for a constant power output goes to infinity as the wind speed approaches zero. Wind is also more expensive than nuclear, in any amount. So there are actually 3 answers to the above question, depending on which basis is considered. For optimum economics, the number is zero. For average power, the number is all of the wind turbines in Texas. For instantaneous power, the number is infinity.  1 week ago
  • Shawn Grannell
    • Shawn Grannell Shawn Grannell The pro-wind author should have said, instead of saying that no evidence is needed, that the mechanics of the wind turbine itself is quite straightforward. Moving air exerts pressure on a rotating airfoil, and work is obtained for generating electricity. Of course it 'works', and there is no new physics involved in describing this. Although science doesn't normally address questions about how much things will cost or should cost, there are other claims involved, such as capacity factor. At one of our conferences in Ann Arbor, someone claimed capacity factors approaching 50% for wind, and capacity factors of 13-17% are commonly quoted. If 963 MW of average power is obtained from 11,000 MW nameplate capacity from all of the wind turbines in Texas, the capacity factor is about 8% and similar results have been obtained elsewhere. The energy obtained from all of the wind turbines in Texas could have been obtained more reliably for the cost and space of one commercial nuclear reactor! At 8% capacity factor, the cost per kwh is more than 12 times greater for an intermittent source than one would calculate by assuming 100% of rated output 100% of the time. In other words, electricity from intermittent sources yielding less than 10% will always be something like 10 times more expensive than it should be, and no future scientific advances in energy storage, strength of materials etc. will ever overcome this. If someone claims that wind has a capacity factor of 30%, and the actual yield turns out to be 8%, then the electricity will be about 4 times more expensive than the claim implies. It seems this capacity factor is like a big rubber band that can be stretched to fit any claim that anyone wishes to make. That's why we always need evidence to support claims, even for things that seemingly obviously 'work'. If it's so obvious, then that evidence should be easy to provide.  1 week ago
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