# Is wind-power a viable backup power source for Mars One?

A question related to What power source options provide reliable and sustainable power generation for a Martian Colony, particularly the answer that solar and nuclear based energy sources being the most likely for any Martian colony. This is also discussed on the Mars One website.

This leads me to the question, given how windy Mars is, would wind power be a viable 'backup' or supplementary power source for the Mars One colony?

Edited to add: has there been any developments in making wind vanes sensitive enough to the conditions on Mars (or similar)?

• Mars might have high wind-speeds, but the atmosphere is also very thin. – Philipp Nov 21 '13 at 8:31
• @Philipp, yes that is true - but has there been any work adapting the technology that we currently have to be able to use the wind on Mars is really what I am getting at. – user838 Nov 21 '13 at 8:38
• @UV-D - it isn't a matter of making the wind-vanes more sensitive - the wind on Mars simply doesn't have enough kinetic energy to move stuff effectively. If we had the tech to generate wind-power on Mars we'd solve the global energy crisis on Earth. – john3103 Nov 22 '13 at 20:43
• The answers to Could you feel the wind on Mars? may be useful. – Fred Jul 25 '18 at 9:18

No, not really.

1. The atmosphere of Mars is very thin. It has below 1% of the pressure on Earth. That means it has less than 1% of the force of wind on Earth with the same speed.
2. Wind only occures at dawn or dusk. Wind happens when there is a pressure gradient between two areas of an atmosphere. Pressure gradients are caused by temparature- and humidity gradients. On earth, these gradients happen mostly at the coasts, because when the sun shines on an ocean, humidity raises a lot faster and temparature a lot lower than when it shines on the dryland. The oceans are one main reason why weather on earth is so unpredictable. But on mars, there are no humidity gradients to speak of and temperature gradients only happen at sunset or sunrise, so you only get wind two times a sol.
• Thank you for the answer - do you have references to include in your answer (non Wikipedia preferably) and what about any developments in the technology? – user838 Nov 21 '13 at 8:53
• But the predictability of the wind on Mars would make it a more reliable energy source. So this does not really give an argument why not to use it, the only downside is that there will be little wind during midday and midnight (if I understand correctly). – fibonatic Oct 22 '14 at 7:30
• fibonatic - constant wind would be much better than this wind limited to twice a day (and in any case, it is only around sunrise and sunset), but point 1 is key here: the wind is nowhere near strong enough. – Rory Alsop Oct 22 '14 at 7:38
• I am not convinced your model of the winds is sufficiently complete to be accurate. Do we have (preferably surface-based) measurements that confirm this? – gerrit Jul 21 '15 at 17:58

It's not that wind is not viable, it's just that it's less viable than other sources of energy.

With such a small part of Earth atmosphere pressure, even the high wind speeds it's insufficient.

Energy scales linearly with pressure but with square of wind speed; for wind turbines on Earth the optimal wind speed is 50km/h; 200km/h of Mars would increase the energy by a factor of 16.

Unfortunately, typical Mars pressure of 600Pa is 0.006 of Earth's average 101,300 Pa.

Combining these, it sets wind turbine efficiency on Mars a little short of 10% of corresponding turbine on Earth. Sure with lower gravity and lower expected wind pressure the construction could be significantly lighter, but still one shouldn't expect any very high output, and the construction would need to be BIG to provide any meaningful amount of energy.

OTOH, while Mars, at 1.523679 AU only receives about 0.43 the amount of sunlight reaching Earth, the thin atmosphere blocks and reflects much less of it, meaning solar panels on Mars are about as efficient as on Earth.

So, similarly to employing geothermal energy on the Moon, - yes, it's possible, and no, it's not practical.

If solar panels with tracking systems are roughly the same cost and complexity as wind turbines of the same output on Earth, on Mars you would get about 10% the energy output of solar at roughly the same cost/effort, or the same energy at 10x the cost/effort comparing to solar power. Maybe a little better if the turbines were optimized specifically for Mars conditions - but still far from breaking even.

• I like this answer because you did some calculations but I have a follow-up. How much efficiency could you gain with turbines at lower gravity? Resistance on ball bearings should be substantially smaller due to that but then they'd be a subject to greater temperature variation... – TildalWave Oct 22 '14 at 10:24
• @TildalWave: The vast bulk of resistance on wind turbines comes from electromagnetic resistance of the generator, so no much savings here. Lower gravity and weaker maximum wind pressure means less mechanical stress on the components, so both taller towers (=stronger winds) and bigger turbines (more surface = more torque). I'm afraid calculations of how much bigger they could be, and how much torque could be gained is a calculation of a month of an expert's time. Still, I seriously doubt you'd come near to 10x the original performance; tripling the efficiency is an optimistic guesstimate. – SF. Oct 22 '14 at 11:09
• Yeah I know but that's the "good resistance" i.e. the one that is converted to electric current. Clearly wind turbines on Mars would have to be built with more reasonable expectations in mind (Earth wind turbines probably don't even move at 10% or they would even consume electricity to spin LOL). But I can't find anything online re the "bad resistance" at nearly three times smaller than the Earth's gravity. There is something about ball bearings designed for Mars but that's about it. I thought you had better luck than me. – TildalWave Oct 22 '14 at 16:07
• @TildalWave: I didn't look, because it's a very minor factor. The real limiting factors are the power input from the wind, and physical durability of the construction under extreme wind conditions (+cost of the construction). The durability requirements rise somewhere between square and cube of the size of the blades. – SF. Oct 23 '14 at 8:13
• See the power output curve for Earth, operating at ~1bar, 10-14km/h is where the turbine starts, 50km/h is where it achieves full capacity. At 90-100km/h it shuts down, setting blades in inert position, to avoid damage. Above 216km/h that doesn't help and the wind will damage the inert turbine nevertheless. On Mars top winds could be expected to be weaker (no humidity or oceans to cause extreme weather conditions) so more fragile, lightweight construction could be expected. – SF. Oct 23 '14 at 8:28

Yes, to an extent. A few key facts:

1. While the atmosphere has 1% of the pressure of Earth's, it consists primarily of carbon dioxide (MW = 44) much more than nitrogen (MW = 28). Thus the effective wind pressure at a given speed is closer to 2% of Earth's.
2. Wind power increases with the square of the wind speed which can be higher then that of Earth.

This has been studied, and the current thinking is that a small amount of ability to use wind power can help when there is less sunlight then the equator has. Technology has been tested in wind tunnels mimicking conditions on Mars, and found to work.

• I think this is a better answer! Whether (no pun intended) or not wind is a more viable energy source on Mars is up for debate and would depend on many other factors - engineering considerations for example - but it is certainly a viable option. – Jack Jul 24 '18 at 19:35

Partial answer, it would be much harder than on Earth.

GIF: A windy day on Mars, remember that Mars' gravity is less than Earth's so the wind isn't as strong as it might appear.

Archived from the Telltale Procjet at Mars Simulation Laboratory: https://web.archive.org/web/20120220080017/http://www.marslab.dk/TelltaleProject.html

Borrowed from (currently unanswered) Was the telltale on the Mars Phoenix Lander used for meteorology? Why not a hot wire anemometer instead?

Development of the Telltale

The air pressure on Mars is less that 1% of the Earths, and this means that the instrument had to be extremely sensitive. The forces due to the wind are of the order of few millionths part of a Newton (The instrument weighs 20 grams, meaning that the gravitational pull is 0.2 Newton). This was accomplished by making the active part of the instrument as lightweight as possible (about 10 thousands of a gram). After intensive testing to document that the experiment would survive the launch and landing vibrations, it was calibrated in the Wind tunnel at the Mars Simulation Laboratory

The power per unit area (Watts/m^2) in wind is given by the kinetic energy density times the velocity:

$$P = \frac{1}{2} \rho v^2 v = \frac{1}{2} \rho v^3;$$

it's linearly proportional to density and cubic with velocity.

There is going to be an extraction factor of order 0.59 or less. See Betz Law limit of 16/27 in:

So at about 0.6% pressure of Earth's, or about 1% of the density, you'd need wind 5x faster to get the same power, assuming the same extraction efficiency.

The problem is that losses due to friction (mechanical & aerodynamic) and possibly more strength to deal with longer blades and/or higher tension when rotating, and the likely very low probability that the wind will be 5x faster than on Earth means this is not going to be easy.

However, there may be other systems to extract energy that are better for Mars than those optimized for Earth.

• This is the same as the answer here but I see that one is likely going to be closed as duplicate, so moving here. – uhoh Dec 3 '18 at 13:35
• InSight has wind sensors, so someday we will be able to put hard numbers into the formulas @uhoh provides. – DrSheldon Dec 4 '18 at 1:23