I’m curious what’s the effect of interfering with the wind patterns?
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[1], so that's 2.11 x 10^25 joules. The mass of the earth's atmosphere is 5.15 x 10^18 kg[2]. 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[2] = 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.
[1] https://en.wikipedia.org/wiki/World_energy_consumption
[2] https://wind.willyweather.com/il/cook-county/chicago.html
The lowest published estimate I have seen for extractable global wind power [1] 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"
https://www.earth-syst-dynam.net/2/1/2011/esd-2-1-2011.html
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.
[1] 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[1] is pretty important if it's true.
[1] "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.
shrug
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.
https://www.researchgate.net/publication/242580464_The_Wind_...
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).