Wind power: Difference between revisions
No edit summary |
|||
Line 1: | Line 1: | ||
[[File:Wind Turbines to the south of Stowford Cross - geograph.org.uk - 410831.jpg|thumb| | [[File:Wind Turbines to the south of Stowford Cross - geograph.org.uk - 410831.jpg|thumb|Onshore wind (wind turbines on land)]] | ||
[[File:Offshore wind farms photographed at the Port of Noshiro, at sunset 20220728.jpg|thumb|Offshore wind (stronger and somewhat less intermittent, on average)]] | |||
[[Category:Energy sources]] | [[Category:Energy sources]] | ||
Line 37: | Line 38: | ||
===Intermittency=== | ===Intermittency=== | ||
Wind power is even more intermittent than [[solar]]. There can be | Wind power is even more intermittent than [[solar]]. There can be months where the wind blows strongly, and months where it barely blows at all. Also, wind turbines can't function when the wind blows ''too'' hard. | ||
{{p2| | {{p2|[suitable wind speeds]| | ||
Most wind turbines can only generate power when wind speeds are between '''3.5 m/s''' and '''25 m/s'''. | Most wind turbines can only generate power when wind speeds are between '''3.5 m/s''' and '''25 m/s'''. | ||
<ref>DASH, Meteorologically Defined Limits to Reduction in the Variability of Outputs from a Coupled Wind Farm System in the Central US [Online], Available: http://dash.harvard.edu/bitstream/handle/1/10981611/Meteorologically%20defined%20limits%20to%20reduction%20in%20the%20variability%20of%20outputs%20from%20a%20coupled%20wind%20farm%20system%20in%20the%20Central%20US_1.pdf?sequence=6</ref> | <ref>DASH, Meteorologically Defined Limits to Reduction in the Variability of Outputs from a Coupled Wind Farm System in the Central US [Online], Available: http://dash.harvard.edu/bitstream/handle/1/10981611/Meteorologically%20defined%20limits%20to%20reduction%20in%20the%20variability%20of%20outputs%20from%20a%20coupled%20wind%20farm%20system%20in%20the%20Central%20US_1.pdf?sequence=6</ref> | ||
Line 44: | Line 45: | ||
When the wind speed is ''too high'', the wind turbine has to switch itself off completely{{x|maybe with the right innovations, it could just dissipate ''excess'' power instead of shutting off completely? {{rn}} }} to prevent damage to the electronics and gearbox. Without this feature, some wind turbines have even been known to catch fire. | When the wind speed is ''too high'', the wind turbine has to switch itself off completely{{x|maybe with the right innovations, it could just dissipate ''excess'' power instead of shutting off completely? {{rn}} }} to prevent damage to the electronics and gearbox. Without this feature, some wind turbines have even been known to catch fire. | ||
}} | }} | ||
This intermittency usually gets "filled in" with [[natural gas]] power plants, but that's not good enough if we want to phase out [[fossil fuels]]. | |||
{{minor|Having multiple wind farms might ''somewhat'' reduce the intermittency. But in practice, this doesn't seem to help much.<ref>David JC McKay, Sustainable energy - without the hot air [Online], Available: http://www.inference.phy.cam.ac.uk/withouthotair/c26/page_187.shtml</ref>}} | {{minor|Having multiple wind farms might ''somewhat'' reduce the intermittency. But in practice, this doesn't seem to help much.<ref>David JC McKay, Sustainable energy - without the hot air [Online], Available: http://www.inference.phy.cam.ac.uk/withouthotair/c26/page_187.shtml</ref>}} | ||
Scaling up [[energy storage]] is already a challenge, even for solar which only needs about a day's worth of energy storage in general. Wind might need several weeks worth. | Scaling up [[energy storage]] is already a challenge, even for solar which only needs about a day's worth of energy storage in general. Wind might need several weeks worth{{x|i.e. could easily need 40 times more battery capacity for the same ''average'' energy consumption rate}}. | ||
Maybe wind energy could be stored via [[hydrogen]], which doesn't have a ''fixed capacity'' the way batteries do. {{x|A battery can only store a fixed amount of energy at any given time. But hydrogen could be produced and stockpiled if necessary (as long as [[hydrogen gas/safety|safety]] concerns are addressed). Hydrogen production units (electrolyzers) still have a fixed ''power'' rating: There's a limit to how much hydrogen can be produced ''per unit of time''.}} [[wind/hydrogen|This has its own challenges.]] | Maybe wind energy could be stored via [[hydrogen]], which doesn't have a ''fixed capacity'' the way batteries do. {{x|A battery can only store a fixed amount of energy at any given time. But hydrogen could be produced and stockpiled if necessary (as long as [[hydrogen gas/safety|safety]] concerns are addressed). Hydrogen production units (electrolyzers) still have a fixed ''power'' rating: There's a limit to how much hydrogen can be produced ''per unit of time''.}} [[wind/hydrogen|This has its own challenges.]] | ||
Line 55: | Line 58: | ||
The best places for wind turbines [[wind/geography|aren't usually near where people live]]. In most cases, the distance is far enough that power lines wouldn't even be viable. {{qn}} | The best places for wind turbines [[wind/geography|aren't usually near where people live]]. In most cases, the distance is far enough that power lines wouldn't even be viable. {{qn}} | ||
This might not be an issue if [[wind/hydrogen]] (as described above) is the main solution. Instead of power lines, the wind turbines would generate [[hydrogen gas]] which would be [[hydrogen | This might not be an issue if [[wind/hydrogen]] (as described above) is the main solution. Instead of power lines, the wind turbines would generate [[hydrogen gas]] which would be [[hydrogen transport|transported]] and used for [[energy]] elsewhere. | ||
We'd need to estimate the full [[EROI]] of such a system, to make sure it's [[Term:viable|viable]].{{rn}} | We'd need to estimate the full [[EROI]] of such a system, to make sure it's [[Term:viable|viable]].{{rn}} | ||
Line 63: | Line 66: | ||
{{pn|This section needs more research to determine which rare metals are needed, in what quantities, and whether there would be enough global [[mineral reserves]] to scale up wind power enough to replace fossil fuels or not.}} | {{pn|This section needs more research to determine which rare metals are needed, in what quantities, and whether there would be enough global [[mineral reserves]] to scale up wind power enough to replace fossil fuels or not.}} | ||
<!-- TALK: | |||
Consider citing the following study: | |||
Increase in demand for critical materials under IEA Net-Zero Emission by 2050 scenario - Yanan Liang †* , René Kleijn † , Ester van der Voet † - † Institute of Environmental Sciences (CML), Leiden University, 2333 CC, Leiden, the Netherlands - Corresponding author: y.liang@cml.leidenuniv.nl | |||
and cross-reference it with USGS data on rare-earth mineral reserves. Seems that even a "net zero by 2050" scenario would use only a very small fraction of mineral reserves - and that most of that is actually for electric car motors, not wind turbines. | |||
--> | |||
===Cement=== | ===Cement=== | ||
Line 172: | Line 182: | ||
|<nowiki>https://ourworldindata.org/land-use</nowiki> | |<nowiki>https://ourworldindata.org/land-use</nowiki> | ||
}} | }} | ||
<tab name="(see maths)"> | |||
{{calc | {{calc | ||
|energy.tfc / wind.capacity_factor * wind.rq_land | |energy.tfc / wind.capacity_factor * wind.rq_land | ||
Line 179: | Line 190: | ||
|{{p2|[discussion needed]|~ <code>wind.rq_land</code> is based in the status quo of wind projects, which are probably on land that's more windy than average. If wind turbines were to be on ''average'' crop land, the energy productivity may be less. Then again, there's also pasture and barren land where wind turbines could be placed too, and there's also offshore wind.{{pbr}}~ If all countries were developed, we'd need more than just <code>energy.tfc</code> - but then again, we don't need to get all our energy from wind; [[rooftop solar]] also has a lot of productive potential.}} | |{{p2|[discussion needed]|~ <code>wind.rq_land</code> is based in the status quo of wind projects, which are probably on land that's more windy than average. If wind turbines were to be on ''average'' crop land, the energy productivity may be less. Then again, there's also pasture and barren land where wind turbines could be placed too, and there's also offshore wind.{{pbr}}~ If all countries were developed, we'd need more than just <code>energy.tfc</code> - but then again, we don't need to get all our energy from wind; [[rooftop solar]] also has a lot of productive potential.}} | ||
}} | }} | ||
</tab> | |||
There should be '''no need''' to destroy natural habitats to build wind farms. | There should be '''no need''' to destroy natural habitats to build wind farms. | ||
Revision as of 18:00, 2 September 2023
Wind power is a possible option for renewable energy.
Wind turbines convert wind to electricity.
A lot of people incorrectly call wind turbines "windmills". But in fact windmills are a much older technology, which use the wind to mill grains mechanically (no electricity involved).
Considerations
#Intermittency | Needs energy storage |
#Geography | Major limitation |
#Rare earth magnets | [RESEARCH needed] |
#Cement | Not a significant problem |
#EROI | Manageable |
#Land use | Manageable |
#Noise | [RESEARCH needed] |
#Recyclability | [RESEARCH needed] |
Intermittency
Wind power is even more intermittent than solar. There can be months where the wind blows strongly, and months where it barely blows at all. Also, wind turbines can't function when the wind blows too hard.
[suitable wind speeds]
Most wind turbines can only generate power when wind speeds are between 3.5 m/s and 25 m/s.
[1]
This intermittency usually gets "filled in" with natural gas power plants, but that's not good enough if we want to phase out fossil fuels.
Having multiple wind farms might somewhat reduce the intermittency. But in practice, this doesn't seem to help much.[2]
Scaling up energy storage is already a challenge, even for solar which only needs about a day's worth of energy storage in general. Wind might need several weeks worth
Maybe wind energy could be stored via hydrogen, which doesn't have a fixed capacity the way batteries do.
Geography
The best places for wind turbines aren't usually near where people live. In most cases, the distance is far enough that power lines wouldn't even be viable. [QUANTIFICATION needed]
This might not be an issue if wind/hydrogen (as described above) is the main solution. Instead of power lines, the wind turbines would generate hydrogen gas which would be transported and used for energy elsewhere.
We'd need to estimate the full EROI of such a system, to make sure it's viable.[RESEARCH needed]
Rare earth magnets
To build a wind turbine
This section needs more research to determine which rare metals are needed, in what quantities, and whether there would be enough global mineral reserves to scale up wind power enough to replace fossil fuels or not.
Cement
The footing of a wind turbine requires a lot of concrete - a potential concern because cement production releases CO2. However, it turns out that the amount of CO2 is not very significant:
McGraw-Hill Encyclopedia of Science and Technology. "Volume generally assumed for the density of hardened concrete is 150 lb/ft^3. (2400 kg/m^3)"
Read more: https://hypertextbook.com/facts/1999/KatrinaJones.shtml
SUSTAINABLE CONCRETE FOR WIND TURBINE FOUNDATIONS www.bnl.gov › isd › documents
"Turbines in the 1 to 2 MW range typically use 130 to 240 m3 of concrete for the foundation"
https://css.umich.edu/factsheets/wind-energy-factsheet
(calculation loading)
Compared to burning gasoline
This is pretty reasonable considering that a wind turbine's lifespan is about 20 years.[3]
EROI
Energy return on investment: About 19.
In other words: wind turbines, over their entire lifespan, produce about 19 times as much energy as it takes to make them.[4] There would still need to be some fossil fuels invested into wind power to "get the ball rolling".
Maybe there are some other wind turbine designs that have a better EROI. [RESEARCH needed]
Land use
Per unit of energy, wind needs far more land than solar
- This is per megawatt capacity (peak), not per average output.
- Stats can vary tremendously based on how windy the location is.
- This stat is based on 172 different wind projects scattered throughout the USA.
- Consider variance: (34.5 +/- 22.4) hectares/MW
- This is the total land use, including the spacing between turbines in a wind farm.
- This is much bigger than [wind.rq_land_disturbed] which is just the land directly impacted by constructing the turbine itself.
Citation:
Land-Use Requirements Of Modern Wind Power Plants In The United States
(Paul Denholm, Maureen Hand, Maddalena Jackson, and Sean Ong)
Page 16
Does not include the fuel used in generating electricity. See [energy.tes] for that.
Citation: "Key World Energy Statistics 2020" IEA
- Page 47 - Simplified energy balance table - World energy balance, 2018
https://css.umich.edu/factsheets/wind-energy-factsheet
(calculation loading)[discussion needed]~ wind.rq_land
is based in the status quo of wind projects, which are probably on land that's more windy than average. If wind turbines were to be on average crop land, the energy productivity may be less. Then again, there's also pasture and barren land where wind turbines could be placed too, and there's also offshore wind. ~ If all countries were developed, we'd need more than just energy.tfc
- but then again, we don't need to get all our energy from wind; rooftop solar also has a lot of productive potential.
There should be no need to destroy natural habitats to build wind farms.
Noise
This section has not been filled in yet.
Recyclability
This section has not been filled in yet.
References
- ↑ DASH, Meteorologically Defined Limits to Reduction in the Variability of Outputs from a Coupled Wind Farm System in the Central US [Online], Available: http://dash.harvard.edu/bitstream/handle/1/10981611/Meteorologically%20defined%20limits%20to%20reduction%20in%20the%20variability%20of%20outputs%20from%20a%20coupled%20wind%20farm%20system%20in%20the%20Central%20US_1.pdf?sequence=6
- ↑ David JC McKay, Sustainable energy - without the hot air [Online], Available: http://www.inference.phy.cam.ac.uk/withouthotair/c26/page_187.shtml
- ↑ United States Environmental Protection Agency (EPA) - Renewable Energy Fact Sheet: Wind Turbines - epa nepis
- ↑ Hall, C., et al. (2013) EROI of different fuels and the implications for society. Energy Policy (64), 141-152.