4 ms·
Let's do a simple calculation, shall we? Wind power is calculated by A * v³ * ρ * η A is the area, e.g. π/2 * r² for horizontal axis designs, ρ is the air de
by qayxc 5y ago
Let's do a simple calculation, shall we?
Wind power is calculated by A * v³ * ρ * η
A is the area, e.g. π/2 * r² for horizontal axis designs,
ρ is the air density and η is the total system efficiency (limited to <59% and safe to assume to be >0.4 for modern systems) and v is the wind speed.
Mars' atmosphere is about 1% of Earth's atmosphere in density. Given a wind speed of 7 m/s² (the optimal wind speed for most modern wind turbines), on Mars we'd get only 1% of the power we'd get on Earth.
A 100m installation (~2.6MW on Earth) would deliver only 21kW on Mars. The average wind speed during a year is slightly higher on Mars, though, at 10 m/s² [0]. The average power output thus would be about 61kW.
The most important time, however, would be dust storms, which render solar useless. Wind speeds have been recorded to exceed 30 m/s² during dust storms. Assuming we can efficiently shield the generator from the dust, the power output would peak at 1.7MW.
A more conservative 17 m/s² for dust storms still yields about 308kW.
100m class wind turbines, while rare on Earth (e.g. GE Haliade-X [1]) would be easier to build on Mars given the significantly lower gravity.
Wind turbines would work on Mars and have great synergy with solar - when solar doesn't work (e.g. during dust storms), wind turbines would be most efficient.
Wind power wouldn't be the first choice for powering a Mars station, though. As can be seen above, installations would have to be pretty significant in size to deliver noteworthy amounts of power.
[0] https://nssdc.gsfc.nasa.gov/planetary/factsheet/marsfact.html https://nssdc.gsfc.nasa.gov/planetary/factsheet/marsfact.htm...
[1] https://www.ge.com/renewableenergy/wind-energy/offshore-wind/haliade-x-offshore-turbine https://www.ge.com/renewableenergy/wind-energy/offshore-wind...
- HPsquared 5y agoA 100m wind turbine would require a lot of material and/or energy to construct, though - some of the materials would have to be processed locally, I wonder what the embodied energy of such a structure would be, and how long it would take to be net energy positive.
- Denvercoder9 5y agoI don't think 100m wind turbines on Mars are feasible anytime soon. Even Starship has only a 18m high cargo area, so even if we assume that blades are assembled out of two parts in-place, you get only a 40m radius. That reduces the average power to just 10 kW. Furthermore, I think your average 10 m/s is an overestimation -- the source gives it as the high limit outside of dust storms.
- qayxc 5y ago> I think your average 10 m/s is an overestimation -- the source gives it as the high limit outside of dust storms. You misread the source then - peaks during sandstorms are 17 - 30 m/s² with 10 m/s² being the annual average. > I don't think 100m wind turbines on Mars are feasible anytime soon. Manufacturing of the wind turbine is assumed to entirely take place on-site. Wind power is not something for a "starter station/settlement". The question was about general viability and given local manufacturing capabilities, wind power isn't completely useless on Mars.
- Denvercoder9 5y ago> You misread the source then - peaks during sandstorms are 17 - 30 m/s² with 10 m/s² being the annual average. Where on the page? The only wind speed related data I can see is this: > Wind speeds: 2-7 m/s (summer), 5-10 m/s (fall), 17-30 m/s (dust storm) (Viking Lander sites) Also m/s² isn't the correct unit for wind speed, since it's a unit of acceleration, not speed.
- dylan604 5y ago>Given a wind speed of 7 m/s² Isn't speed m/s and acceleration m/s/s?
- qayxc 5y agoYep it is - typo on my part.
- godelski 5y ago> would be easier to build on Mars given the significantly lower gravity. In one sense yes, but in another sense no. Consider erosion. It is the bane of existence for any system near the ocean. Mars has a similar problem with dust, which is smaller than what we see on Earth. This shreds electronics and other instruments on Mars. Sealing becomes far more important, but also more difficult. The other thing we need to recognize is that on Mars there's no electric ground. So yeah, on surface things look easier but there's a reason why including domain experts in the conversation is necessary. This is a classic example of napkin modeling being representative of how things will work in reality. So look to the domain experts. They've used solar and nuclear for a reason. Maybe dig into why those were the choices made.
- ncmncm 5y agoWhat does it mean to say "there is no electric ground" on Mars? You would not be willing to drive a spike deep into the ground, as is done on Earth? Or are you saying that without ground moisture, the ground would not be conductive enough?
- godelski 5y agoIt has to actually do with the magnetosphere. It's not about will to put a spike of metal into the ground but that doing so doesn't create an electric ground like it does on Earth because there is not this electromagnetic differential.