The down side to wind power

https://news.harvard.edu/gazette/story/2018/10/large-scale-wind-power-has-its-down-side/

by todd8 • 8 years ago

63 57 8 years ago

news.harvard.edu

chki• 8 years ago

To estimate the impacts of wind power, Keith and Miller established a baseline for the 2012‒2014 U.S. climate using a standard weather-forecasting model. Then, they covered one-third of the continental U.S. with enough wind turbines to meet present-day U.S. electricity demand. The researchers found this scenario would warm the surface temperature of the continental U.S. by 0.24 degrees Celsius, with the largest changes occurring at night when surface temperatures increased by up to 1.5 degrees. This warming is the result of wind turbines actively mixing the atmosphere near the ground and aloft while simultaneously extracting from the atmosphere’s motion.

I am confused: How does the warming work exactly and is this actually a global climate effect? Because this part of the article makes it sound to me as if it's just a very localised change of temperature caused by the exchange of different air layers, which can't be right? Because you couldn't really compare that to climate change on a global scale.

qaq• 8 years ago

Given climate fluctuations is 0.24 even meaningful? Also hard to imagine 100% being wind power.

beat7• 8 years ago

It's good science to analyze the long tail, even if we will never be on the long tail, because those extreme questions can have meaning in less extreme conditions.

pjc504• 8 years ago

It is indeed a change in local surface temperature - that is, if you have a thermometer there, it will read 0.24 degrees higher (average across 24h) than it would if there wasn't a nearby wind farm. And yes it's apparently due to atmospheric mixing. I imagine it would have similar effects on crops, evaporation, etc as a global temperature rise.

The next question: should this be subtracted from the measurements of any weather station suitably close to a wind farm?

ams6110• 8 years ago

The example is clearly hypothetical only. We're never going to cover one third of the continental US with wind turbines.

The more important information to me is that neither wind nor solar have the power density that has been claimed.

For wind, we found that the average power density — meaning the rate of energy generation divided by the encompassing area of the wind plant — was up to 100 times lower than estimates by some leading energy experts

...

For solar energy, the average power density (measured in watts per meter squared) is 10 times higher than wind power, but also much lower than estimates by leading energy experts.

Then you have the separate problem that the wind doesn't always blow and the sun doesn't always shine, so you need a huge storage infrastructure (batteries, presumably) alongside the wind and solar generating infrastructure.

IMO nuclear is the only realistic alternative to coal to provide reliable, zero-emission "base load" power generation. Wind and solar could make sense in some use cases but not in general.

bilbo0s6• 8 years ago

IMO nuclear is the only realistic alternative to coal to provide reliable, zero-emission "base load" power generation...

Yeah, but no one wants to pay for it. Which is why you'll see more wind and solar with hydro-storage, and even more geo-thermal energy plants in the future. Even with all the extra infrastructure, it still comes in at less than 2 or 3 cents a kwh long term. Whereas even if you take a very optimistic long term view on nuclear, it's just REALLY hard to get down below 3 cents. So for nuclear sources to get higher in the dispatch stack, government must take on more of the costs.

But then, of course, if government is taking on more of the costs, then you're still paying more than 3 cents. Probably a lot more. You'd just pay it in extra taxes instead of a utility bill. So, yeah, I guess that's why energy is a hard problem. No easy solutions really. Just hard to balance pros and cons to every known technology at this point.

(Maybe someday someone will figure out this whole fusion thing and we'll be able to consign all these other, less refined, technologies to history's dust bin?)

frgewut• 8 years ago

I have started to view "baseload" generation more in a negative sense (as in "can't be easily turned on/off").

Also the daytime/nighttime power consumption differs almost twice, so almost any solar added only smoothens out the difference.

Also the new offshore wind turbines (>10MW) offer some extraordinary capacity factors (~60%). Makes me wonder what these capacity factors could be if we could get to 20MW turbines.

beat7• 8 years ago

Why is nuclear capacity easier or less expensive to build than storage capacity for wind/solar?

Be sure you're not starting with a conclusion and working backwards to the data required to support it.

KineticLensman• 8 years ago

so you need a huge storage infrastructure (batteries, presumably)

The approach in the UK is to build Combined Cycle Gas Turbine [0] stations rather than storage infrastructure, as CCGT can be spun up quickly if renewables aren't cooperating. When I checked this awesome dashboard [1] just now, 48% of the UK's power was CCGT compared with approx 12% wind solar, presumably partly today has been still foggy. On good days solar and wind get to 30%.

[0] https://en.wikipedia.org/wiki/Combined_cycle

[1] http://www.gridwatch.templar.co.uk/index.php

westurner• 8 years ago

IMO nuclear is the only realistic alternative to coal to provide reliable, zero-emission "base load" power generation. Wind and solar could make sense in some use cases but not in general.

How much heat energy does a reactor with n meters of concrete around it, located on a water supply in order to use water in an open closed loop, protected with national security resources, waste into the environment?

I'd be interested to see which power sources the authors of this study would choose as a control for these just sensational stats.

From https://news.ycombinator.com/item?id=17806589 :

Canada (2030), France (2021), and the UK (2025) are all working to entirely phase out coal-fired power plants for very good reasons (such as neonatal health).

Would you burn a charcoal grill in an enclosed space like a garage? No.

djrogers• 8 years ago

Buried in the article:

they covered one-third of the continental U.S. with enough wind turbines to meet present-day U.S. electricity demand. The researchers found this scenario would warm the surface temperature of the continental U.S. by 0.24 degrees Celsius

That’s a ridiculous basis upon which to form a conclusion. For reference, that would require building 200,000 copies of the single largest wind farm in the US - the 3,200 acre Alta farm.

pjc504• 8 years ago

The intent there is presumably to construct a "worst case" - US powered entirely by wind - and see what the magnitude of the effect is. If it was 2.4 or 24.0 then it would be a more serious problem, knowing that it's 0.24 is a good result.

ncmncm• 8 years ago

They say closer to the poles, wind power cools. So, put wind power systems at higher latitudes, and solar at lower latitudes -- where it is more effective. Sorted.

I look forward to the day when the rotors are taken down (and used for roofing?), the pods mined for their rare earths. The towers will have loose mesh stretched between them, and collect wind power by releasing ions against an electric field maintained by the mesh. (This was patented in the '80s by Alvin Marks. Expired, now, both.)

fiblye• 8 years ago

So does this only affect ground temperatures in a localized area?

Because if Kansas gets 0.24 degrees warmer but the greenhouse gas reductions result in Greenland not melting off into the ocean, it seems like a clearly worthwhile tradeoff.

sevensor• 8 years ago

Speaking of Kansas, one of the other things the article mentions is that turbines slow down the wind. It might not be such a bad thing for Kansas if the wind was slower. Less topsoil erosion, for one thing.

piker• 8 years ago

Isn't the math on solar really simple? (1) Annual amount of energy the sun generates on the surface of the earth minus (2) the annual amount used by non-human forms of life and natural processes equals (3) annual human energy balance. Now, maximize capture of (1) while minimizing externalities of such capture. How is anything other than direct solar-to-electricity conversion on the table long-term? Presumably even wind energy production relies on surface temperature differentials stored over periods longer than the consumption period in question--meaning, there's a resource being depleted.

cjbenedikt• 8 years ago

Misleading headline. Real one: Observation-based solar and wind power capacity factors and power densities

Theodores2• 8 years ago

There was a time in the UK when waterwheels were all the rage. It is hard to imagine today but there was a time when rivers in wool making areas were slowed down to no longer flow due to the amount of water wheels present. The external effects of the water wheel was known but there was little that could be done if you were downstream of other mills taking power from the river.

I look forward to the time when we have the 'too many wind turbines' problem to solve.

pbhjpbhj• 8 years ago

Is that true, surely there's a terminal velocity that's reached by water flowing down a riverbed after - I'd guess - a hundred metres or so (probably much less)? Given the mill is not reducing the volume of water, surely it gets back to speed in time to hit another mill a couple of miles downstream.

Silting, I'd think would be a problem.

Theodores2• 8 years ago

The mill buildings were really close, a couple of hundred on five small tributaries, each tributary running no more than a few miles before converging to one river that had even more mills on it, larger and not so dependent on river speed. The river had been dredged and otherwise adjusted by people at the time for it to have subsequently been used for the canal of the area. It is therefore hard to imagine how it once was, particularly given that water wheel technology evolved too.

goplusplus• 8 years ago

This is practically a non issue. Not only would it be unrealistic to use wind power for 100% of US power generation nor would it be a good decision since a huge benefit of renewable energy is that we can diversify among so many different source.

brixon• 8 years ago

Wind is also hit or miss. I don't live in an area of the country with consistent wind suitable for power generation. The entire SE part of the US is not suitable for wind power. https://www.nrel.gov/gis/images/30m_US_Wind.jpg

24gttghh• 8 years ago

Your map ignores the coastal zone, as shown in a comparable map (for the 50m height):

https://www.nrel.gov/gis/images/US-50m-wind-power-map.jpg

Most of that offshore zone is on the continental shelf.

hwillis• 8 years ago

Unlike solar power, land use is effectively a non-factor for the price of wind power. The NREL estimates the financing of land area to be less than a third of maintenance[1] and just 16% of operational expenses. That works out to land use being .06 cents per kWh.

Also, NB for context that .24 C is fairly small compared to the temperature anomaly as it is currently. The global anomaly is .6-.85 C higher over the year[2], and over the US it's usually around 2 C[3]. Note also that 5-20x more area, as they clarify in the journal, is not really representative; the number of turbines is about the same (unless you are in a very population-dense area like Germany), they just have to be spread much farther apart. For instance you can plop them down on farmland just fine.

Computational methods may also help reduce the impact of wind shadows by decreasing "dirty" air, but that's just a band-aid. From what the journal indicates, the limiting factor is energy re-entering from the higher atmosphere. I'm curious how this kind of thing is affected by water vapor. Does it increase or decrease the problem? Are offshore turbines affected the same way? How does farmland play into this, since plants release huge amounts of water into the air via transpiration (a plant's "heart" is effectively driven by evaporation)?

Also, I liked their little map[4] of wind(squares)/solar(stars) capacity factors. It's refreshing! One of the most irritating things about power discussions online is the ubiquitous repetition of blatantly wrong statements about capacity factors (power delivered/nameplate capacity). Here's[5][6] the data:

Coal: 53.5% capacity factor CC natural gas: 54.8% Nuclear: 92.2% Hydro: 45.2% Wind: 36.7% PV Solar: 27% Solar thermal: 21.8%

People are all over the place saying solar has a 10% capacity factor, wind has 20%, nuclear has 98%, coal and hydro have 90%- it's nonsense! Coal is a destabilizing influence on the grid, and wind is practically as good as hydro. When you account for how well solar tracks with daily demand, it's better than hydro.

[1] https://www.nrel.gov/docs/fy18osti/70363.pdf

[2] https://www.climate.gov/news-features/understanding-climate/...

[3] https://www.ncdc.noaa.gov/sotc/service/global/map-blended-mn...

[4] https://cdn.iopscience.com/images/1748-9326/13/10/104008/Ful...

[5] https://www.eia.gov/electricity/monthly/epm_table_grapher.ph...

[6] https://www.eia.gov/electricity/monthly/epm_table_grapher.ph...

bigpicture• 8 years ago

I've driven through wind farms in middle America and for the most part, each tower has a small gravel pad around it with a gravel access road to the nearest public road. Everything in between is farmed as normal. While the overall footprint is large, the majority of the land continues to be used in the way it has always been used. If all the farmland in America became one gigantic wind farm, I don't think you would see a noticeable difference in agricultural production, especially as the farmers collecting lease payments are going to be able to invest in newer equipment.

So when they say that a downside to wind power is the much larger amount of space required compared to previous expectations, is it in the NIMBY "I don't want to see a turbine when I look out the window", or something else? I'd like to give the authors the benefit of the doubt; I wish they'd spent a little more space explaining the downside of the land requirements.

pjc504• 8 years ago

I think there was the implied question "can we scale up wind power or are we going to run out of space?" Not all locations are equally suitable for wind power; one of the observations was that capacity per turbine has gone up but overall area required remained constant. That implies that builders have got better at siting them in precisely optimal locations - but everywhere nearby is less optimal. The paper also proves that there is a slight negative return to scale on huge wind farms.

The implications of these are that more area than expected will be required. I don't think there is any consideration beyond that of implications in this paper.

plytheman• 8 years ago

Given what you say about wind farms being placed on traditional farms, I wonder if the localized warming the paper discusses would actually be a benefit to the crops. It could extend growing season just a bit more and maybe help buffer against frosts and cold-snaps.

dawnerd• 8 years ago

A lot of farms already use wind turbines to keep freezes away as long as they can. They’re all over California, mostly in orange fields. Some places used to even burn oil at night.

https://extension.psu.edu/orchard-frost-protection-with-wind...

Recurecur• 8 years ago

So when they say that a downside to wind power is the much larger amount of space required compared to previous expectations, is it in the NIMBY "I don't want to see a turbine when I look out the window", or something else?

Extra space means extra dollars. It seems that the necessity for reliable backup power, and overly optimistic output projections figure into wind power's costs being underestimated.

From the article: "The observation-based wind power densities are also much lower than important estimates from the U.S. Department of Energy and the Intergovernmental Panel on Climate Change."

Utility solar installations aren't looking good either: "For solar energy, the average power density (measured in watts per meter squared) is 10 times higher than wind power, but also much lower than estimates by leading energy experts."

strainer4• 8 years ago

The analysis in the papers as well as the article quite deceptively presents possible surface temperature effects in a 100% onshore windfarm scenario, as a factor of global warming.

I view this as a controversy motivated inversion of the fact that wind turbines extract energy/heat from the atmosphere in contrast with heat plants (fossil and nuclear) which necessarily release around twice the amount of useful energy they output, as heat to local air and water resources.

A global warming or cooling effect of atmospheric mixing is not established here or obvious to predict, being complicated by cloud cover, precipitation, natural vegetation and farming albedo changes... yet in the context of this "downside discussion" it is associated to wind as a technical risk.

This kind of modelling is of crucial importance to environmental stewardship, but this kind of analysis is at best a stimulating exercise and at worst an obstruction to long over due investment in the clear technological solutions that we are fortunate to have at our disposal. (Wind power wouldn't be much use if fated with a Martian type atmosphere)

jessriedel3• 8 years ago

As I interpret your comment, you are dismissing this paper's conclusions about warming effects using just the arguments that (1) intuitively wind power absorbs energy, not releases it like combustion; and (2) the atmosphere is complicated. Is that it?

(1) seems like an obvious red herring since the heating/cooling effects of fossil fuels have nothing to do with the thermodynamic energy release of combustion. And (2) isn't an argument for cooling, just uncertainty, and you've given us no reason to trust you over a journal article.

strainer4• 8 years ago

Wind turbines do absorb energy from the atmosphere, that is clear thermodynamic fact not my intuition. Having arranged an atmospheric modelling capability, these researchers should have included the scenario for heat plants concentrated emissions in their study, or at least in a full discussion.

"heating/cooling effects of fossil fuels have nothing to do with the thermodynamic energy release of combustion"

Re-examine that assumption - If windfarm's might cause problematic warming through atmospheric mixing, how have you assumed ground level heat emission from power plants can cause none? There is actually a growing body of research into this which indicates significant geographical warming is possible. You could look into "effects of anthropogenic heat flux on climate"

growlist• 8 years ago

I think the planet would thank us for using far less power overall, rather than continuing to be profligate with cleaner power. That said I'd need to read the paper properly to understand it - I don't think this article explains the key points very well.

Interested to know if this applies to offshore wind? Here in the UK we are a great candidate for this and whilst the US isn't quite so fortunate, it still has a fair amount of coastline!

village-idiot• 8 years ago

And this is why pursuing efficiencies in energy consumption is important too!

Gravityloss• 8 years ago

It's local, not global warming.

nayuki• 8 years ago

Don't let the perfect be the enemy of the good.

666lumberjack• 8 years ago

Unless we see major breakthroughs in the field of Fusion energy or long distance power transmission (Fibre optics for beamed power? Very high temperature superconductors?), I'm more and more convinced that immediate reliance on solar+wind is an unrealistic goal and we desperately need to be building nuclear plants as a stopgap.

compelledToken• 8 years ago

This is FUD, to be sure. Don't think so? Hear me out.

If wind turbines are even 10 stories tall, then they introduce the same atmospheric disruption as a residential or commercial building of the same height. That we are not researching the impact of urban sprawl with the same level of scrutiny is telling. What of smoke stacks, cooling towers and high rises? Hmmm?

Meanwhile, the idea that removing kinetic energy from a 400 foot thick layer of a wind's pattern's convection and coriolis path represents atmospheric drag any worse than trees is an idea to be laughed at. What about thermals from parking lots? What about desertification?

Indeed, watch all the hurricanes disappear, because we soaked up all that motion with fan blades dotting the terrain. Does anyone believe that a wind shadow carved into the Atlantic coastline with an array of modern windmills could effectively disrupt hurricane alley? I sure don't.

And no, I don't think that's a grossly oversimplified comparison.

The down side to wind power

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