Ok, you seem to be more knowledgeable on the subject than I am and I probably misinterpreted the chart as well. I was just trying to say turbines aren't the end all solution since most places don't seem to have enough wind. But there should definitely be push for using more renewable energy sources and improving the associated technologies.
Also, maybe you can give me some numbers so I can plug them into this formula. What is the wind conversion efficiency for a turbine? What is the typical rotor diameter? And how many turbines per unit area on a typical wind farm?
energy generated per turbine = efficiency * (power per unit area) * area * time
total energy generated = (available area) * (turbines per unit area)
Fair point - I did the calc all at once and screwed up my parentheses. My point still stands. How realistic is it to manufacture 500,000 x2.5 = 1.25 million wind turbines, needing 27 trillion kWh to do so, in 10 years?
I just can't leave well enough alone, and did a quick and dirty very high level analysis:
For a low to middling wind site in the US, with a 7.5 m/s average wind speed represented by a Rayleigh distribution:
Using a GE 1.5-77, the most common turbine in use in the US in the late 2000s, I calculate 40.5% gross capacity factor, and estimate net capacity factor of 33.5%.
Using a GE 2.0-116, one of the most energetic turbines on the market for low-wind sites, I calculate a 53.2% gross capacity factor, and estimate a net capacity factor of 44.1% using the same annual loss parameters as before.
For a hypothetical project of equivalent size we get over 30% more energy every year from the same wind by only changing from the old technology to the new, and we build less infrastructure to support it. The new machines are taller, and we probably need the same amount of total land for the project.
Wind power accounts for about 10% of total generation in the US. So even if turbines were added to account for 100% generation, and demand increased 10x, it'd still be far less than anything else on the list.
> At a 42% capacity factor (i.e., the average among recently built wind turbines in the United States, per the 2021 edition of the U.S. Department of Energy’s Land-Based Wind Market Report), that average turbine would generate over 843,000 kWh (843MWh) per month—enough for more than 940 average U.S. homes
For comparison, an actual nuclear reactor in practical use produced 4,697,675 MWh in 2017. That’s the equivalent of 5572 of those wind turbines.
That’s a lot of wind turbines. But if we can build 278 wind turbines per year and it takes 20 years to build a new reactor. They’re even.
I don't see an obvious connection between those charts and why wind can't get much bigger. It just shows that wind is currently producing ~26% of the power demand. Would you mind spelling it out since it is not self-evident to me?
Interestingly, the very first statement is quite misleading. The statement:
> On average, a humble wind turbine uses less land area per megawatt-hour than almost any other power source.
The article itself refers to this citation [1]. It says, unsurprisingly, that the most land efficient power source is nuclear. The statement is of course technically true because it says "almost any power source".
With wind, however, even that is tricky because you can either count just the area directly below the turbine body, which is still higher than nuclear and unreasonably optimistic because you severely limit a far bigger area. If you count also the spacing (too pessimistic on the other hand because part of the land might be used for farming) then wind farms range across the whole scale of land efficiency.
I think its fair to say that land use of wind farms is "complicated", but saying its almost the best in this regard sounds like manipulation.
"We examine 119 wind turbines from 50 different analyses, ranging in publication date from 1977 to 2007. We extend on previous work by including additional and more recent analyses, distinguishing between important assumptions about system boundaries and methodological approaches, and viewing the EROI as function of power rating. Our survey shows an average EROI for all studies (operational and conceptual) of 25.2 (n = 114; std. dev = 22.3)." https://www.sciencedirect.com/science/article/abs/pii/S09601...
Initial hot take: I'm not sure they're measuring efficiency in a way that's really meaningful to me?
There are so many ways you could measure it. You could measure it as the % of wind energy passing through the turbine's plane that is taken out of the air, or the the efficiency of using that energy to get the rotor turning, or the efficiency of converting the rotor's kinetic energy to electrical energy.
(edit: Or I could, y'know, do the sensible thing and check the article. They're measuring power output for a given wind speed and direction. Which I think means, in effect, all of that end-to-end.)
But I'm not sure any of those are, in and of themselves, what really matters at scale. The more interesting questions, I'm guessing, are things like, "How much energy can we get out of a plot of land of a given size?", or, "How much energy can we generate for a given cost to install and maintain?" Both of which, I would assume, are more difficult to directly extrapolate from thermodynamic efficiency in wind turbines than they are for something like photovoltaics, because of the "moving parts" factor.
That question is literally a massive research project and I couldn't begin to answer it here. The best place to start is probably the DOE 20 percent by 2030 report released in 2008.
The US has huge amounts of available wind energy, but constrained supply chain, development, and transmission resources. 20% by 2030 is technically possible but will require huge amounts of work.
I'm not sure I understand. Sure, letting turbines spin and not use the power, while burning extra gas, isn't worse for the environment than just burning gas in the first place (though it's significantly more expensive to triple-pay for the energy), but it's better is to turn that unused power into used power.
The article wasn't decrying the existence of excess wind power, it was trying to describe the best solutions for using that power.
You've highlighted my essential issue with wind (and other renewables). Under the guise of "ah the dumb public won't understand", things like the actual expected output of a wind farm are hidden. It's a long enough road to renewable energy without hiding away the essential facts. The capacity factor, and resulting actual output of a wind farm, is the most important figure, along with its cost (which is a whole different debate).
Also, as has been pointed out, the loose use of terms for power and energy in the article is enough to make an engineer wince.
Please link to a source/calculation where a wind turbine uses more resources than a coal plant to build. I mean, you can even do napkin math and see that there’s no way multiple buildings and vast mining infrastructure take less material than a turbine farm.
Also, maybe you can give me some numbers so I can plug them into this formula. What is the wind conversion efficiency for a turbine? What is the typical rotor diameter? And how many turbines per unit area on a typical wind farm?
energy generated per turbine = efficiency * (power per unit area) * area * time
total energy generated = (available area) * (turbines per unit area)
Then I can redo my calculation using 29 PWh as the total energy consumption for the US (http://en.wikipedia.org/wiki/Energy_in_the_United_States). Just curious now, don't want to start an argument or anything.
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