Are 'Renewables' Worth the Trouble?
I came across a debate recently between Francis Menton and Lord Christopher Monckton. It turned on what Lord Monckton calls the "Pollock limit." Named after Chilean engineer Douglas Pollock. Unfortunately, no paper is cited and, though I looked, I couldn’t find anything written by Pollock himself on his limit. It’s always best to go to original sources if one can. In this case I couldn’t, so must rely on Monckton.
Monckton’s explanation of the Pollock limit is on the site Watts Up With That. The critique by Menton and the rejoinder by Monckton appeared on the Manhattan Contrarian here and here. Have a look if you haven’t seen it. On second thoughts, Monckton’s algebra is both bewildering and demonstrably wrong and best avoided. Stick with me here for a clear account. Why give an account at all? The substance of the issue raised by Monckton is important, as also is what the debate says about the scientific method.
The nameplate capacity of a wind turbine greatly exceeds its average output of power. There are various estimates. Monckton says that in the U.K., onshore wind delivers 25 percent of plated capacity. Penn State puts it at between 32 and 34 percent in the U.S. I’ll use a figure of 25 percent without loss of generality. The arithmetic’s easier.
According to the Pollock limit, wind cannot deliver to a grid more on average than 25 of its plated capacity. Take a small isolated town of 10,000 households. It requires a constant supply of electricity of 12MW. Don’t ask why it needs as much electricity of a night as of a day, it doesn’t matter. It pays a government-subsidised carpetbagger to build six turbines close by with a nameplate capacity, all told, of 12MW. Part of the time it’s windless and little or nothing is delivered. Part of the time the wind is optimum and 12MW are delivered. On average per hour over a year 3MW are delivered. Luckily the town has diesel generators.
Let’s build another six turbines says the Mayor. Now what happens. When the wind blows optimally, 24MW are delivered; of which 12MW are uselessly redundant unless the town has a humongous ultra-expensive battery to store the excess power. When the wind doesn’t blow the extra turbines don’t help. Nothing is delivered and the diesel generators work overtime. But, and here’s the point, when the wind lies between zero and its optimum, the extra turbines help to deliver additional power.
For instance, if the wind is sufficient on any particular day to generate 6MW of power from six turbines, then twelve turbines will deliver 12MW; the diesel generators can be turned off. Thus the average amount of power delivered to the town over a year exceeds 3MW when twelve turbines are brought into play. More than 25 percent of the town’s power needs can be met on average; which exceeds the nameplate capacity of a wind turbine. QED, the Pollock limit is breached and the opaque algebra employed by Monckton is proved wrong by the test of experience. Menton makes the same point and he too, no mathematical slouch as his backroad attests, obviously can’t make head nor tail of the algebra. To wit, “I have difficulty parsing the sentence,” he says gently of one line of an algebraically-imbued sentence. Quite!
Monckton’s rejoinder, largely repeats his defective algebra, with accompanying pique. The pique has a number of elements to it. Describing Menton as writing a “hit-piece” and showing “unjustifiable discourtesy… gratuitous discourtesy… unprofessionalism.” And consider this for an insult:
I have seldom seen a more blatant instance of Aristotelian logical fallacy excoriated by medieval schoolmen as argumentum elenchi.
Stick that in your craw, plebeians. I haven’t mentioned one piece of pique. That is the accusation by Monckton that Menton is over-skeptical about climate skepticism; showing “churlish ungenerosity towards the work of other skeptics.” I will come back to that. First to substance.
Monckton has for a long time been a powerful force for good in the climate debate. And whatever its faults, this current intervention draws vital attention to the limitations of renewables. That can’t be overdone. Sure, the Pollock limit is non-existent as a technical obstacle, but it highlights how costly and impracticable it would be to get anywhere near close to 100 percent of power needs from renewables. It would require a combination of massive overbuilding and massive storage. Now, to be fair, Monckton is on this page too, particularly in his rejoinder; nevertheless, he stubbornly reverts to the validity of the invalid Pollock limit.
As to the impracticability of getting anywhere close to 100 percent of power from renewables, consider my fictitious town. When the wind near the town is slight and six turbines are delivering half their average amount of power; namely 1½ MW, then to get to 12MW not another six but another 42 turbines (seven banks of six) would be required. When the wind blows optimally, 7 times 12MW equals 84 MW of excess electricity would pour into the town’s grid. Calamitous I would think. Intermittent power supply is unworkable and unaffordable. That’s the size of it and only the fanatics in charge think otherwise.
Now back to Monckton charging Menton with being too skeptical of our side. In fact, skepticism defines our side. Our side searches for the truth wherever it leads. The truth is most often hard to find and pin down. That’s why internecine squabbles break out among climate skeptics. The other side doesn’t squabble. They stick together around whatever dung heap is their agenda du jour. Truth be hanged. The squabble between Monckton and Menton is part of the scientific method. Hypotheses are put up. Efforts are made to test whether they stand up to scrutiny and experience. They are torn down if they don’t. Fully embrace this process and make halting progress, otherwise wallow in error and superstition. There is no halfway house.