4 ms·
The world used about 180,000TWh of energy in 2022[0]. That requires about 21TW of generation capacity. If we assume wind turbines have a capacity factor of abou
by jl6 3y ago
The world used about 180,000TWh of energy in 2022[0]. That requires about 21TW of generation capacity. If we assume wind turbines have a capacity factor of about 30% due to the intermittency of wind, we would need about 69TW of nameplate capacity.
If each of these turbines is rated at 16MW, we would need about 4.3 million of them.
Is there enough space?
Let's assume turbines should be spaced 10 rotor diameters apart[2]. A turbine of this size (246m diameter) would need to have about 2.5 * 2.5=6.25km^2 of dedicated space. So we will need about 27 million square kilometers of open sea space.
Coincidentally, that's the same as the total area of continental shelf in the whole world.[3]
Continental shelf depth is up to 200m.[4]
The deepest wind turbines today are in depths of 59m.[5]
What should we conclude? As long as we figure out a way of building turbines in deeper water, or perhaps floating turbines, and a way of manufacturing the required materials (hopefully without recourse to fossil fuels), the project seems just about plausible. But it would be a truly planet-scale endeavour.
[0] https://ourworldindata.org/energy-production-consumption https://ourworldindata.org/energy-production-consumption
[1] https://en.wikipedia.org/wiki/Capacity_factor#Wind_farm https://en.wikipedia.org/wiki/Capacity_factor#Wind_farm
[2] https://ideasmedioambientales.com/wind-turbine-spacing/ https://ideasmedioambientales.com/wind-turbine-spacing/
[3] https://en.wikipedia.org/wiki/Continental_shelf https://en.wikipedia.org/wiki/Continental_shelf
[4] https://www.britannica.com/science/continental-shelf https://www.britannica.com/science/continental-shelf
[5] https://www.sse.com/news-and-views/2023/04/world-s-deepest-offshore-wind-turbine-foundation-is-installed-in-scottish-waters/\\ https://www.sse.com/news-and-views/2023/04/world-s-deepest-o...*
- robin_reala 3y agoIs anyone seriously proposing a wind turbine monoculture for energy generation?
- jl6 3y agoPick your desired percentage of wind in the future energy mix. Even if we say 25%, it's still going to need millions of turbines. And our energy demands are not shrinking.
- Shaanie 3y agoMy country produces around 20% of its energy from wind nowadays, 2010 it was less than 3%. Seems to work just fine and is growing rapidly.
- matthewdgreen 3y agoWe built about a million aircraft globally during WWII (specifically: 1939-1945). I’m not saying the average WWII airplane compares perfectly to a modern wind turbine, but the technology and industrial base we used to do this was also vastly more primitive. So yes, I’d bet that a sufficiently-motivated human society can crank out a million turbines over a multi-decade time span. You can Google the IEA “Net Zero by 2050” report to find estimates of how much offshore wind capacity there is (it’s a lot.) It does illustrate the specific challenge of this energy transition. If a given energy technology isn’t being mass-produced in factories, it’s basically irrelevant given the scale of what we need to do.
- Someone 3y ago> And our energy demands are not shrinking. I think they should be, but even if they aren’t, there still is the observation that a kWh of electricity often can produce more of what we really want (light, motion, compute power) than a kWh of oil (about the only thing we can efficiently convert that into is heat) For example, Google tells me - petrol is about 12 kWh/kg, - the modern fiat 500 has a 47l gas tank, - Tesla sells cars with 50kwh batteries. Yet, that Fiat doesn’t have ten times the rang of the larger Tesla.
- landemva 3y agoEnergy consumption is an indicator of living standards. I hope we harness and use much more reliable energy!
- adrianN 3y agoEnergy consumption is a bad indicator of living standards. Everything that defines my living standard has become much more energy efficient during my lifetime. I have for example more light in my house than I used to and consume about 20% of the energy I used to. My induction stove uses a lot less energy than the wood fired stove my grandma had at her house. My current computer uses about a tenth of the electricity of my computer twenty years ago and does much more. An electric car uses about a third of the energy of a gas car. A heat pump uses about a fourth of the energy of a fossil furnace.
- hannob 3y agoYou're confusing primary energy with useful energy. What people need to realize is that if we go to renewable, electric energy, in most cases this will also involve efficiency improvements. Many fossil fuel based processes are horribly inefficient, with electricity you can often avoid doing things like "80% of our energy goes into heating up the air around whatever we're doing". That said: Yes, we'll need a lot of wind turbines.
- jl6 3y agoI don't mind being conservative for this exercise, and renewables have their own inefficiency issue: we'll need to accept the inefficiency of using electrolysis to produce the hydrogen needed to synthesize the feedstocks needed to run petrochemical processes (e.g. producing plastic), because energy production isn't the only thing that depends on fossil fuels.
- Dylan16807 3y agoThe goal is to stop turning fossil fuels into CO2. Plastic production is not an urgent issue.
- ZeroGravitas 3y agoThere are however various companies looking to e.g. make ethylene from CO2 which, if made economically viable, simultaneously fixes previous fossil CO2 release, and further reduces the financial viability of continuing to drill for more fossil gasses.
- adrianN 3y agoHydrogen production is about 80% efficient and only a small part of our needs depend of hydrogen.
- jrmg 3y agoThat’s just a 2100x2100 square. How much ground area does one of these turbines need? I know that in reality you couldn’t just put them all in one place.
- giomasce 3y agoI heard that the total wind power across the whole world is something like 20 times the total power humanity needs. So if we ended up doing this, we'd stealing some 5% of power from the wind, which is quite a lot. This itself could have significant climate consequences. Solar shouldn't have this problem, instead: the amount of power we receive from the sun is ridiculously larger than what we can ever thing to consume.
- adrianN 3y agoI don't believe that number, wind is essentially second hand solar power and insolation is orders of magnitude larger than what we need. Do you have a source?
- adrianmonk 3y ago> of open sea space I'm not disagreeing with your math, but it doesn't need to be offshore only. Currently 93% of wind power is on land, and 7% is offshore[1]. In the United States, it's much more extreme. Literally 99.99% of turbines are on land and 0.01% are offshore[2]. Offshore is growing faster than onshore, though. --- [1] See "Technology deployment" section here: https://www.iea.org/energy-system/renewables/wind https://www.iea.org/energy-system/renewables/wind [2] See this map: https://eerscmap.usgs.gov/uswtdb/viewer/ https://eerscmap.usgs.gov/uswtdb/viewer/ . It shows 72,731 wind turbines, 7 of which are offshore. Also see this Wikipedia article: https://en.wikipedia.org/wiki/List_of_offshore_wind_farms_in_the_United_States https://en.wikipedia.org/wiki/List_of_offshore_wind_farms_in...
- askvictor 3y agoThere are designs for floating turbines (but they still need to be anchors to the sea floor). Though I wonder if, on scale, they could be made into a flotilla that would only need a smaller amount of anchors for the whole thing, and also be towed around if needed.