As a contrast, it was also reported today that Hinkley point will be £2.9 billion over budget: https://www.bbc.com/news/business-49823305 luckily for them, they get to charge £92.50 per megawatt hour upon completion - locked in for 10 years. While wind power is costing us £40 per megawatt hour, not guaranteed, and likely to decrease.
Driving through central Kansas, the towers are just this stark reminder of how far we've come, and how little we are. You see nothing, nothing, nothing... then BAM! These massive towers generating energy from the winds on the plains, in a state named for the people of the south wind. All of them impossibly tall, the field going on for miles, your mind doesn't even really process how big an individual one is, let alone the scale of the whole farm.
They always hit me like a monument. Like that feeling you might get walking into a cathedral with a slow whistle up at the ceiling. It's more than that, though, it's bundled up with a bit of futurism from the new tech, a bit like finishing a piece of utopian sci fi at the same time.
There's no accounting for taste, for sure. So maybe some people are just accustomed to the way certain views used to look and don't want any change. Maybe they grew up there and have strong attachments.
It's just hard hearing people dismissing beauty as blight, something that could be sublime if they just looked at it a slightly different way.
I wish I'd been able to go up to the top. Must be amazing!
I don't dislike the design of wind farms, but sure as hell I'd prefer landscape unspoiled by a forest of big white rotating blades. Given the choice, I'd prefer a concentrated energy generator (whatever that might be), that can be hidden away. So in some sense, I do believe they are a blight on the landscape.
Because of the long winters, to do the same with wind/solar will require about 3-5 times as much cost as you might think at first. You need to provide extra capacity to artificially increase effective capacity factor, and then you need about 48 hours of storage. Also possible, but about the same price, is hydrogen for seasonal storage for winter.
...and generally speaking, effectively any carbonfree project being built now needs to be supported. We need everything. Including a lot more off-shore wind.
The energy markets in Europe are connected and the fastest growing source of energy is basically wind. Coal is shrinking at this point and the enthusiasm for building new gas plants is likewise melting away rapidly as their cost seems to be on the high side compared to clean energy solutions. It will take decades to get rid of both of course.
Sweden and Finland actually both have nuclear plants. Finland even built a new one recently. But in general, nuclear is on the way out in Europe as there is no political will to commit to building new plants across the continent. Older plants are shutting down one by one. France has a lot of aging nuclear plants and they don't seem to be building new ones and are actively considering shutting a few down (https://www.france24.com/en/20170710-france-hulot-could-clos...). Apparently keeping their existing capacity online would take tens/hundreds of billions and the political appetite for those investments is pretty low.
Many EU countries are on a path to completely clean energy and it does not seem to involve building new nuclear plants.
David MacKay covers this in his excellent book: https://www.withouthotair.com/c18/page_103.shtml
As for political will I feel we should first start with the numbers and works out what adds up. If people don't want nuclear but nuclear is the only path to zero carbon then we'll need to choose one or the other.
Right now we can make great progress by ignoring nuclear because there's lots of things to be done. So go all in on renewables and ditch nuclear is a politically easy choice. Does great things for the stats and many people don't like nuclear. Will it take us all the way though?
I've not seen any figures which don't add up except ones which make some rather outrageous assumptions (e.g. no demand side management, no overproduction, intermittency stats based upon smaller, shittier turbines, etc.).
David Mackay's book is good but it's rather outdated - the figures are from 2006/2007 and renewables have plummeted so far in price since then that it rather changes the picture of what's achievable.
>So go all in on renewables and ditch nuclear is a politically easy choice.
I don't believe that's necessarily true. The nuclear lobby has spent a lot of money trying to make their choice politically easier.
The nascent renewables lobby, by contrast, doesnt' spend nearly as much on lobbying.
IMHO clean energy will take us a lot further than just our current base line needs because of these improvements. For example, right now people are reluctant to install air conditioning because of the cost of energy and concerns about global warming. Cheap, plentiful, clean energy changes that. If house owners can generate all the energy they need for a one time cost of installing batteries and solar, this concern goes away.
Hydrogen will be popular for things like heavy industry, shipping and other places where delivering large amounts of electricity cheaply is needed and batteries won't be good enough. These use cases are far fewer than most hydrogen fans hope/expect and IMHO excludes most forms of four wheel traffic on the road I don't see a business case for installing massive solar infrastructure when EV ranges are hitting 400+ miles already with rapidly improving recharge rates.
Most of that hydrogen will be generated using excess wind or solar and the business case for that will be that that energy is so cheap that the relative inefficiencies don't matter. It will have to compete with other synthetic fuels because at that point fossil fuels will be no longer be cost competitive with that either. Why buy barrels of oil at 50-100$ each when you can just convert kwh + water + air into carbohydrates?
Nuclear is on a slow but steady way out. At this point there are only a handful of countries investing in nuclear and quite a few have non technical reasons for this (i.e. military ones). R&d progress has been glacial and cost is an order of magnitudes from being competitive in the current market already. In most places that still have nuclear, it's one of the most expensive options in the market and there are a lot of nuclear plants at risk of shutting down early because of it.
IMHO fusion might still happen in half a century or so. By then most countries will have shut down all remaining coal, gas, and nuclear plants. At that point it will have to be super cheap to be off interest.
They are still in the process of building it, and it is set to become the second most expensive building built in modern times. 
It should be reduce carbon no matter the dollar cost, right?
It's utterly delusional to think that low density generation such as solar or wind can meet the growing energy needs without covering vast areas.
And electric vehicles will just increase the need.
The point is that nuclear is expensive. You get more energy per dollar by building renewables.
(and for the same reason, we should be looking at expanding hydro and geothermal)
So while I definitely think we should build solar and wind, it's ridiculous to just dismiss nuclear out of hand for cost reasons if the goal is 100% clean energy (unless you have, say, massive amounts of hydro power).
Given the climate emergency, it's silly to pit one clean energy project against another when in fact we need all we can get. Particularly in the case of variable renewables, as they benefit tremendously from being in a source-diverse power grid.
What do you mean by this?
Yes, some tiny European countries can rely on hydro or geothermal for baseline generation. Most countries can’t, and even if they’re a net exporter, they’re heavily dependent on fossil fuels (or nuclear) for filling in gaps.
Battery technology is nowhere near sufficient for the need, things like pumped storage are space intensive, and exotic stuff like hydrogen and molten sodium and whatnot are decades off. Something has to fill the gap. Nuclear is a good choice.
I expect more nuclear to be shut down than being delivered during that time. It's not a growth market.
20-30 years from now, several countries are planning to be 100% on renewables and most of those are not planning to build any new nuclear plants. Most of the remaining countries will be making similar plans in the next ten years.
I think it's even longer than that, unfortunately... of course, it depends how much over capacity you have, but those cold fronts in N Europe can kill wind speed for weeks on end sometimes IIRC. It is a huge problem for us to solve.
It's a huge problem in terms of time and finance but not a difficult technological one.
Would have been ~500MW as originally envisioned so still not this big =)
Edit: Missed the 137x in the wikipedia article so had the wrong power rating.
> even the extended operation of existing reactors is not climate effective as operating costs exceed the costs of competing energy efficiency and new renewable energy options and therefore durably block their implementation. Mycle Schneider concludes: “You can spend a dollar, a euro, a forint or a ruble only once: the climate emergency requires that investment decisions must favor the cheapest and fastest response strategies. The nuclear power option has consistently turned out the most expensive and the slowest.”
Hardly an unbiased source it seems.
Regardless, the issues facing nuclear power could be quite easily solved with simple political will. Unlike those of renewable energy, which still do not have economical or technologically feasible solutions to the storage and base load problem.
We need only look to France to see the path forward. After the 1973 oil crisis, they resolved never again to be beholden to foreign oil for their grid needs. So they undertook the Messmer Plan, which mass produced a single standardized reactor design in bulk. France converted itself almost entirely over to nuclear power for its base load requirements in just 15 years, with the project coming in under budget and ahead of schedule. Now France has so much electricity it sells excess to Germany for profit.
Taking advantage of economy of scale, slicing through red tape and NIMBY-ism with political willpower, using a standardized design to expedite the engineering and approval processes of every individual plant - none of these require some amazing new technology or some new economic system be developed. We could literally start tomorrow, and have the entire first world swapped over to nuclear by the 2030s.
I hope nobody does that. France is running several overdue reactors, has a history of under-reporting issues, the main electricity generation and distribution company EDF (owned by the state) runs with a net debt of €70 billion and is responsible for the disastrous over budget numbers for Hinkley OP mentioned above.
> Now France has so much electricity it sells excess to Germany for profit.
Germany sells excess electricity also...It's a flowing market depending on daily prices. The overall price development however showed that it rose in France while it fell in Germany: https://ec.europa.eu/eurostat/statistics-explained/images/4/...
With the continued rise of renewable energy in Germany this development won't stop while France will at some point have to start moving some of their overdue reactors off the grid while new ones are being dropped because of the market situation outlined in the Status Report above: https://www.reuters.com/article/us-france-nuclearpower-astri... while the only other new reactor they build Flamanville 3 came up in the news with messed up welding seams...
Red tape is there for a reason. Red tape is the rule of law, it's emissions standards, and fines for polluters, employment rights, and safe drinking water.
Red tape isn't something to be cast aside to get your own personal pet thing done.
I mean, what's the difference between your 'political willpower' and dictatorship?
Meanwhile... The British approach makes it illegal to give government funding for the Channel Tunnel rail link. 12 or 15 years later, another Act is needed and we start bothering with HS1. HS2 and HS3 were allegedly "coming soon" while the Chunnel was being built. Hmm.
Plus the British approach has just built the biggest offshore wind farm. Why is that inferior to Frances nuclear power?
Plus France also signed up to the Channel Tunnel treaties, so its also illegal for them to fund it, but yet it still got built...
And which approach gets to claim credit for Concorde?
I'm not even sure what the French approach is. They still have to follow EU red tape, I could just as easily roll out a stereotype about long lunches, etc, etc.
The French were the driving force behind Ariane. Britain would most likely have walked away after the failure of Europa (Blue Streak). We did after all walk away from our space programme right after achieving orbit. Still we became a much smaller participant in ESA than we had been in ELDO. Germany took our place as the other key player with the French.
The point about the Tunnel was the British Tunnel Act specifically ruled out state aid - Thatcher's government expected the private sector to stump up the whole cost. Which it pointedly failed to do. France happily took the SNCF proposal and built a national network from it using the power and purse of the state. Britain took the BR APT prototype, pushed for far too early demo, cancelled it, sold it to Fiat then bought them later as Pendelinos. We chugged along with HST.
Concorde is a brilliant pick, thanks for the perfect example! I'm going to say 95% "The French" (politically. We contributed much more fairly technically): The British really, really wanted to partner with the US who weren't interested feeling they would be giving "their" lead to the UK. We were most surprised to find the French were the most serious about SST too, and Thorneycroft (destroyer of Supersonic Harrier) found himself with only France as realistic option. The treaty was written with very heavy cancellation penalties. Roy Jenkins tried to cancel it with TSR2 in 64. He went to France to tell them. The French responded by breaking diplomatic contact. :)
Actually, scrub that, it wouldn't have progressed nearly as far as British project. Treasury were against, cabinet was against, but, we were trying our first attempt to get in the EU and de Gaulle wasn't keen (he felt we were too close to the Americans to be good Europeans. 2019 hindsight thinks he may have had a damn good point). Concorde was an EU/EEC bargaining chip. Yet still we tried to cancel it.
> The TGV was the world's fourth commercial and third standard gauge high-speed train service, after Japan's Shinkansen, which connected Tokyo and Osaka from 1 October 1964, the Russian ER200 around 1974 (full service in 1984), and Britain's InterCity 125 on main lines such as the East Coast Main Line, which entered service in 1976.
It was far enough that it would have been faintly visible from Bournemouth beach. I strongly doubt that a few dots on the horizon would have bothered any tourists.
This project wasn't killed because of the view. There were other financial (probably carbon based) interests involved.
Based on the expenses scandal??
That is incredible!
You use 8kwh==28.8MJ of energy per day. 28.8MJ/7MW turbine is about 4 seconds, as a watt is a joule per second.
In this case, there are two distinct timescales involved: the scale on which the energy is used (an hour or day) and on which it's generated (a second). It's ok to keep track of those separately.
If you want to compare, however, you will have to convert to common units, and I at least find it easier to use watts and joules than watt-hours/second and watt-hours. By all means convert to stationary-bike-hours and big macs or whatever unit at the end but calculations are easier in the SI units.
Hubble's constant is expressed like that because it is a nice unit for the math.
Three really: seconds, hours and days.
8 kWh per day = 8 Joules per second ⋅ hours per day ~= 330 Watts
Sometimes you even get four time units in one go. e.g. "I averaged 8 kWh per day last year"
Unless you are running an extremely energy intensive commercial operation at home, there's a lot of low hanging fruit to be picked. Get an energy audit yesterday. That could hugely benefit all of your comfort, your wallet and the environment.
For reference, I use 30kWh/day but I live in an 80 year old all-electric house (heating, water, cooking, ...) where temperatures go down to -30 degrees celsius and winters last for 6 months. Plus both my wife and I work from home so the heating and lights etc. are on all the time. And I still think it's way too much !
We don't keep the house exceptionally cool. 78° during the day, 74° on the second floor at night just before bed.
I really need to try and track things down a bit better. I've got two sub-panels and it's a lot of circuits to track it down. I can start by monitoring the obvious things though: A/C units, refrigerators, dryer. I recently replaced two of the A/C units, but around the same time switch from natural gas dryer to electric and that seems to have been a wash.
Power comes from a nuclear plant less than 10 miles away, so at least it's clean? :-(
Two 14 SEER units, one 3.5 ton, one 3 ton, and a 10 SEER 2 ton unit.
1 ton = 12,000 BTU.
(6.5 x 12000) / 14 + 2 x 12000 / 10 = 7971 watts.
The air handlers have 1/5 HP motors, call that another 150 watts per air handler, so we're up to 8500 watts at least.
52 kWh / 8.5 kW is a little over 6 hours, or 1/4 of the day.
To use less power and still have a comfortable home, I'd have to insulate it better and switch to smaller and more efficient A/C units. The units are sized properly according to:
I was like "That seems high" so I checked my usage meter and it say 112kWh. OK then. Then I notice it's set to monthly.
So that's about 4kWh per day. It will be a bunch more in winter, and your place is much bigger than mine, but still - that number seems kinda crazy huge to me.
School kids are taught (well, at least I was) small habits such as boiling just the amount of water that you need, cooking with the lid on, turning off the oven 5 minutes before the meal is done, etc.
These energy saving habits are motivated by taxes on energy consumption.
The average household in Denmark use 4.4kWh/day per person (1600kWh a year) and the current recommendation is to be aiming at 1000kWh/year.
 https://sparenergi.dk/forbruger/el/dit-elforbrug (in Danish)
A few weeks ago I was on holiday. Usage was 2.5kWh per day, about 100W, which is the fridge and a low power PC (NUC).
Otherwise, it's 3-6kWh per day, and depends whether I did laundry and cooked or not.
District heating and water.
Somewhat ironically, one factor that has greatly facilitated the development of offshore wind in the UK is the world leading expertise in offshore construction gained through decades of exploitation of North Sea oil and gas.
Looks like the capacity factor is around 38% so the turbines are making ~3500hp avg.
"Horsepower" as a unit made sense when it was being used to market steam engines as an alternative to horses, because it made the tradeoffs obvious: it's clearly cheaper and easier to maintain steam engine than the 20 horses needed to do the same work. It might still be relevant for something like tractors where horses would be a reasonable alternative, but something like "carbon tons" (the tons of carbon produced by fossil fuel production of the same electricity) might be a more useful comparison for wind power.
One gallon of diesel when burned makes around 10.336kg of co2. So each turbine is preventing around 2 tons per hour of co2 emissions. Could be as much as 5 tons if it is replacing coal.
Apologies for use of freedom units; habits are hard to break.
The title should say has the capacity to power 1M homes. No wind farm ever generates to capacity. And they age very quickly.
This tech maybe better and last longer than in the quoted, but it will still degrade over time. So in 10 years maybe it will be 20%?
Wind is not reliable – so where does the power come from when the wind is not blowing? If you say batteries, then you need excess generation (a lot) and a lot of batteries.
* Gas peakers
* More interconnects, particularly to places with pumped hydro resources
* Batteries (yes, it needs a heck of a lot. But battery tech & economics are still improving)
* Solar PV (we can build interconnects to the larger installations being built closer to the equator in places like N Africa)
Also worth noting the citation you posted is from 2012. Wind turbines have changed significantly just in the last 5 years. I wonder what the numbers look like today, in particular load factor decay?
1.5 WIND POWER GENERATION
Denmark had the highest share (Percentage of the average annual electricity demand covered by wind) (41%) in Europe in 2018.
The figures represent the average of the share of wind in final electricity demand, captured hourly from ENTSO-E and corrected thanks to national TSOs and BEIS data.
Wind and solar are intermittent sources which makes them seasonally irregular and requires backup energy from other more stable sources such as coal, oil, gas and nuclear.
An interconnected sustainable grid would foster the necessity of developed countries properly paying back to the atrocities committed to to underdeveloped countries, with things such as:
1) Investing in development, education in such countries
2) Investing in sustainable energy generation there
3) Subsidizing the costs of much 1st world technology in order for those countries to rise out of extreme poverty
Again, just simple examples; used African continent but could be extended to many other places. We need a "Green New Deal" because extreme capitalism has failed to a point we're now facing our own extinction if things continue like they are. Sure, sounds like wishful thinking, or something that would require some kind of ultimate class-based warfare, but I do believe this path can be achieve without a bloodstained revolution. The alternative is to be enslaved by the plutocracy and eventually to die off as a species, in the far future. Or bear arms and get your hards dirty, but I'm not an advocate for that.
What Greta has said in the UN, I agree with her: the current way dominant classes are acting upon the world's most damning issue seems to be a simple act of looking with a blasé face and not caring. If the wealthy believes all those billions are just going to watch as life becomes utterly difficulty on this planet, they may find not everyone is as peaceful as I am.
In short, there's no sustainable future with the way capitalism operates currently.
The only way to solve this is through capitalism not through the currently politically motivated energy capitalism where they pick the winners.
Capitalism certainly ain't perfect but it beats all other structures hands down. It does so because it recognizes human nature which is part selfishness and part altruism and existing in a gradient depending on the relationship of the partners it's in.
Keep in mind that most of our success as rich nations is because of our use of energy especially fossil fuels.
There is no current sustainable energy generation that can solve the increasing need for energy without the use of more fossil fuel and there is no curren green energy supply that can deliver as stable as Nuclear.
The chances of Greta being alive today without the use of fossil fuel and our energy consumption would be much lover. We don't owe anything especially not to a little girl who is being misused by cynical politicians and environmental organizations to make unscientific claims and to blame the very generations that have made sure she is able to grow up in the most safe environment of all times.
Capitalism is the only way we can move forward, the idea that a few politicians know what to is exactly the kind of dangerous thinking that is leading us towards a less safe, less prosperous world.
Ridiculous right wing smears. Is this what the pro-nuclear lobby has sunk to?
So we need something groundbreaking with high energy density and scalability and which is cheap.
This number seems unbelievable.
Are the rotors falling off the towers and not getting replaced?
Are you sure that number is correct ?
recent installations have higher capacity factors than installations 10 years ago.
These numbers seem to show the progress in wind power technology over the past 10 years and not a degradation of existing installs
So if this is 1 million homes, that's 6 megatons of CO2 saved per year. The world emits 37 gigatons per year. So this saves 6/37,000, or ... I just got depressed.
Every (very little) bit helps, right?
One of the fun exercises to run would be a win farm that was powering a submerged data center (so that it could dissipate heat into the ocean).
More critically they have zero impact on the forces that actually generate wind in the first place.
Folks, if you don't know the answer, don't answer.
In this case, giving the numbers of how much we'd need to harness to have an effect is pointless. We aren't really in any kind of a place to grasp the enormity of the numbers. Numbers that big really do become meaningless.
Wind is just second order solar energy. Massive amounts of solar energy make it to Earth in a given year. I suppose if you must have a number, we can work in either kWh or BTUs. Won't really make a difference to the enormity of the outcome though.
For instance, in BTUs, about 80 million british quads of the energy that the sun gives earth will make it to the surface in a year. (I know the sun delivers more than 80 million british quads, but I'm not counting the 30% that gets reflected). Now I'll be nice, and say an additional 10-20% of that is absorbed by biomass. (It's not, it's way closer to 10%, but I'm being nice.) And an average American home uses what? say 50 million BTUs a year, (About 12 - 15 thousand kWh), if they're being profligate?
So the wind is coming from the interplay of the solar energy absorbed by different areas of the ocean and different areas on land. (Another caveat, our atmosphere can trap some of the energy, which will add to new energy sent by the sun, and kind of spiral in that fashion. This is what happened to Venus, which is why they have like 500 mile an hour winds there.) In any case, ignoring the climate warming, we'd have to find some way to harness enough wind to make an impact against, say, 20 million british quads of BTUs.
Yeah. That's not gonna happen.
This is what I mean by incomprehensibly massive numbers. Basically, we'd have to harness enough wind to power roughly 5 billion groups of US homes, where each group would contain about 1 trillion US homes each. That would be just to have a 1 percent impact on the energy in the winds on this planet in a year. And the required number goes up with global warming, because more wind.
At this point we're talking monopoly money man. It's meaningless. Again, we don't have the smarts or technological know how to do anything even close to that, and don't really have any kind of frame of reference as a species to meaningfully ponder the implications of such enormous numbers and amounts of energy. Even thinking about it only makes you consider the smallness of mankind.
If that's true, that's all the more reason not to comment.
You're saying we can't grasp the numbers, but apparently you think you can grasp them well enough to conclude that humans won't have a significant effect.
If we really can't grasp the numbers, then the only conclusion we can come to is that we don't know. I think "I don't know" is something that we need to say more often if we're being honest with ourselves.
> For instance, in BTUs, about 80 million british quads of the energy that the sun gives earth will make it to the surface in a year. (I know the sun delivers more than 80 million british quads, but I'm not counting the 30% that gets reflected). Now I'll be nice, and say an additional 10-20% of that is absorbed by biomass. (It's not, it's way closer to 10%, but I'm being nice.) And an average American home uses what? say 50 million BTUs a year, (About 12 - 15 thousand kWh), if they're being profligate?
> So the wind is coming from the interplay of the solar energy absorbed by different areas of the ocean and different areas on land. (Another caveat, our atmosphere can trap some of the energy, which will add to new energy sent by the sun, and kind of spiral in that fashion. This is what happened to Venus, which is why they have like 500 mile an hour winds there.) In any case, ignoring the climate warming, we'd have to find some way to harness enough wind to make an impact against, say, 20 million british quads of BTUs.
Back-of-napkin math is pretty unconvincing. For example, you made no mathematical connection whatsoever between the energy from the sun numbers you were throwing around, and the amount of that that gets converted into wind energy. You said that 80 million quads of energy hit's the earth from the sun, so your "20 million British quads of BTUs" is arbitrarily choosing to say that 1/4 of the sun's energy is converted to wind?
So let's sanity check that. quads is a unit of energy E, and E = 1/2 x m x v^2
Now let's convert our numbers into reasonable units and plug them into the equation. 20 million quads = 2 x 10^7 quads. 1 quad = 1.055 x 10^18 joules, so that's 2.11 x 10^25 joules. The mass of the earth's atmosphere is 5.15 x 10^18 kg. Plugging these numbers into E and m in the equation, we get:
E = 1/2 x m x v^2
2.11 x 10^25 = 1 / 2 x 5.15 x 10^18 x v^2
2.11 x 10^7 = 1 / 2 x 5.15 x v^2
4.22 x 10^7 = 5.15 x v^2
2.1733 x 10^8 = v^2
14700 = v
So yeah, the numbers you are using are incomprehensibly large because they are wrong, wrong, wrong by a few orders of magnitude.
To be clear, this isn't a criticism of wind power. It's obvious that the clear and present danger of global warming is a much more pressing concern than unknown effects of wind power. It's a criticism of people answering questions they don't know anything about.
Let's convert that to wind speed:
E = 1/2 m x v^2
5.67 x 10^20 = 1 / 2 x 5.15 x 10^18 x v^2
5.67 x 10^2 = 1/ 2 x 5.15 x v^2
1.134 x 10^3 = 5.15 x v^2
2.2 x 10 ^ 2 = v^2
14.8 = v
For comparison, average wind speed in Chicago, the windy city, from 2010 to present was 9.9 miles/hour = 4.43 m/s.
Before you lose your calm, and conclude that wind power is evil, let me reiterate, back of napkin math STILL shouldn't convince anyone of anything. I'm merely posting this to show that back of napkin math can be used to calculate much different results.
The lowest published estimate I have seen for extractable global wind power  is as little as 18 terawatts in the paper by Miller, Gans, and Kleidon:
"Estimating maximum global land surface wind power extractability and associated climatic consequences"
18 terawatts happens to be exactly equivalent to an annual energy output of 5.67 x 10^20 joules.
18 terawatts is the low end of the estimated range in this paper; the upper end is 68 terawatts.
 The authors only considered wind farms placed on land, perhaps because offshore wind was so much more expensive in 2011. Their lowest estimate is too low, even if you stick with the rest of their methodology, after adding offshore wind.
Nope. I may have messed up my calculations somewhere, but I'm quite confident in my equation (kinetic energy E = 1/2 x m x v^2).
That paper looks pretty interesting, but I'm going to follow my own advice and admit I don't know: I don't have the background to evaluate the validity of their atmospheric model. The conclusion is pretty important if it's true.
 "Furthermore, we show with the general circulation model simulations that some climatic effects at maximum wind power extraction are similar in magnitude to those associated with a doubling of atmospheric CO2. "
This says nothing about how energy flows through the system, which is what will determine the impact on wind speeds.
> This says nothing about how energy flows through the system, which is what will determine the impact on wind speeds.
I'm not gonna teach you guys high school physics. You can look up E = (1/2)mv^2 in any Physics textbook or your favorite search engine.
Before you disagree further, try calculating this yourself. Look up how to calculate the final speed of an object from kinetic energy. Make sure you plug energy units (i.e. joules) into E and power units (i.e. watts) into P. This isn't hard math, and the necessary equations are all over the internet.
If you used the former, it would tell you that wind speed would be reduced by 0.04m/s. If you used the latter, 1.4km/s.
You're not using the equations incorrectly, but they're not telling you what you think they are.
They are telling you - if we store up all the power use of humanity for this length of time, then use it to blow the air, how fast will it go.
...because when I pulled the number from wikipedia it said it was the energy consumption for a year, not for a day or a century.
> You're not using the equations incorrectly, but they're not telling you what you think they are.
> They are telling you - if we store up all the power use of humanity for this length of time, then use it to blow the air, how fast will it go.
...no, it's telling me if we collect the energy used by humanity during this length of time, then use it to blow the air, how fast will it go. You cannot use "energy" and "power" as if they were interchangeable, they are not.
What you may be missing is that these physics equations go both directions. If we take the blowing of the air and use it to produce the energy used by humanity during this length of time, we'd expect to see the same decrease in speed.
The decrease in speed you're describing is one time, not continuous. This is the issue both parent and I are pointing out. It's a shame to me that you aren't willing to see your error and instead resort to nitpicking, but I'm not going to try to explain a third time.
That's if you care about energy. If you care about vortexes and disturbed flow... I have no information.
Have you actually done some formal measurement in front of and behind the wind farm?
Because the way you're writing suggests not.
Btw turbines do slow down the wind and it is measurable, turbines at the back produce less energy than those at the front, wind farms are laid out specifically to try and avoid this.
I could be entirely wrong and maybe changing the wind pattern will be the "pulling hydrocarbon liquids out of the ground and burning them" of 2119.
There are 174 turbines in an area of about 300 sq km. If they were laid out on a grid the grid size would be about 1.3 km. The blades have a diameter of about 24 m.
Feels to me like that's far enough apart to not massively affect the wind.
One way to approach it, is what % of the total wind in the world would it take to power 100% of our energy needs? If it is something like 50%, it seems like it would be very possible for large scale wind to eventually do something to our wind patterns. If it is something like 1% or .01%, it seems pretty unlikely to do much. (part of this assumes you would never power 100% of your energy needs with wind due to variability).
That said, I don't think we can necessarily assume that 1% or 0.01% would have a small effect. Small perturbations can have large impacts in complex systems. It is possible impacts could be significant in localized ways as well (for instance low change in global average temperature but greater incidence of hurricanes).
It’s a persistent myth, and recently back in vogue due to the tweeting of a certain orange personage, but wind farms as bird-destroyers are not worth worrying about.
However, according to the Royal Society for the Protection of Birds, there's no evidence cats are causing problems for bird populations in the UK at least.
This might be different elsewhere though.
And the bats are at risk too
I still think these wind farms are vastly positive, but we should recognize the problem with bird populations, and find clever ways to mitigate it, instead of putting the question aside just because "the bad orange men" said this was happening.