Sunday, October 3, 2021

In the Wind

 Via Maggie's Farm:


Sam L. said...

Wind power is a necessity...for Congress-critters.

David Foster said...

I don't think this is correct. As a simple check: The capital cost of onshore wind is about $1300 per kilowatt, so a 2 MW wind turbine costs about $2.6 million. The companies that make and install wind turbines are profit-seeking companies, so the cost of the energy used for the production and installation *is included in the selling price*, along with labor costs, etc and any profit made.

A 2MW plant will, conservatively, produce about 16 MWH per day, which is 16000 kwh. If this electricity is sold for a wholesale price of $.03/kwh, that is $480/day or $175K/year. Payback for ALL the capital costs associated with the wind turbine, of which embedded energy is only a part = 14.8 years.

This analysis from Vestas deals specifically with energy payback:

and cites an energy payback of 7.7 months. Vestas makes these things, so they're presumably biased, but even if they're off by 3:1, that's still less than 2 years.

There is plenty wrong with wind, including intermittency, vast amounts of land utilization, and ruination of scenic views, but negative life-cycle energy is not among the flaws.

Anonymous said...

Your math is flawed. IF as you claim the wind powered generators paid for themselves after 15 years THEN why subsidize them? And the subsidy is HUGE. 50%-80% of the cost and almost all of the electricity generated is subsidized by requiring power companies to purchase it and pass the HUGE cost on to consumers. If Wind or PV was practical why subsidize it???

DeNihilist said...

The elephant in the room is the base which is made of concrete, the number 1 producer of CO2 in the world. The area of the base is about the size of a football field and can run up to 10 feet deep. I am surprised that the article did not incorporate this stat.

David Foster said...

No one wants to just recover their costs on an investment; they also want to make a return. So you can't just look at the payback in years, you also have to look at the desired return on capital if you want to look at the financial viability of a project.

The cost data comes from a report done by engineering firm Sargent & Lundy for the EIA:

...I did not include the "fixed O&M cost" number, since the focus of this discussion is on energy return rather than financial return, but if you include it the financial payback is 21 years. This is within the expected operating life of 25 years. Payback is achieved, but the financial ROI will be terrible. Don't have time to do a formal analysis at the moment, but I'd guess you need a wholesale electricity price of 4 to 6 cents per kwh to achieve a decent ROI

The point remains that the energy used to manufacture and construct the wind turbine is recovered within the first year or two of operations. Energy, though, is not the only thing that matters; human labor matters too, as do things like system resiliency and scenic views.

Ares Olympus said...

Certainly fossil fuels seem like a great deal, like taking 1 million years of oil and natural gas stored in the ground, from ancient sunlight and burn that amount each year and see if you can repeat year after year.

Certainly wind is less convenient, but where it blows, it'll keep blowing whether we harness it or not. And sometimes there's too much, and then we have to find a way to store or use the surplus to try to keep earning a return on our investments. Its so hard to solve such problems, but engineers seem to like to do it.

Finally I don't know where Adam Vail gets his facts from, but this 2014 article says otherwise: The payback for the associated energy use is within about 5-8 months, and even in the worst case scenario, lifetime energy requirements for each turbine only takes 1 year of operation.

Similarly I know environmentalists like to complain about the costs of nuclear power, which we can easily see comes from over-regulation and a lack of scalability - building ONE nuclear plant is expensive, but if we make 100 of them and plan on a 50 year lifetime, costs will fall.

Myself the only reason I like Musk's ideas of humans on Mars, is there are no fossil fuels there to burn, and no free oxygen to burn even if we did find ancient coalbeds, so hard challenges here become necessities there. Mars astronauts will use solar power, geothermal, wind power as they can, and nuclear when they must.

Linda Fox said...

The numbers from David Foster assume a best-case scenario (which, in practice, we never get). It doesn't take into account the enormous subsidies received from the Federal government, nor the backup systems necessary to offset the non-constant nature of the energy conversion, nor the cost of the blade replacement.
And, it appears that blade maintenance sharply diminishes once the subsidies run out (around 10 years in the USA) -
The THEORETICAL lifespan of these machines is high, it's true. But the ACTUAL lifespan may be considerably shorter. And, the blades are made in China - given their supply chain issues of late, that may not be a long-term viable solution.