Methods and technologies for removing dust from photovoltaic panels on Mars

[sghill]

So, I’ve been thinking about the problem of removing dust from solar panels and windows on Mars.   Basically, any PV panel or window will get dusted over in time on Mars, so how does it get cleaned? These panels could be on a robotic or manned rover, lander, or part of an occupied base.

Below are several methods I can see working on Mars for cleaning panels and windows. I’d like this thread to be used to voice thoughts about these 4 methods, design thoughts for each, as well as other cleaning methods that may be useful.

Method #1: Working Fluid- water or some other fluid (ammonia?) is sprayed onto panels and windows.  Positives: This is the most common method for removing dirt and dust from panels on Earth. Cleaning can be very thorough when combined with a cleaning agent and sheeting agent.  Negatives: Any fluid will be expensive, and can leave residue. Low pressure on Mars may make fluid behave differently during the cleaning process (For example, rapid boil-off may cause "poka-dots" of dirt to form on the panel instead of running off). Also adds mass for a rover. Panels must be at an angle to be cleaned.

Method #2: Vibrator motor- A small motor with an off-set weight attached like in cell phones spins up and vibrates loose dust from panels and windows.  Positives.  This device is extremely simple and lightweight.  Would work very well on a rover or fixed array as a “dog shaker.”  Negatives: There are moving parts that can wear out. Mars dust may be sticky, and won’t fall off easily using a vibration method.  Also, the motor’s vibrations could potentially dislodge or loosen other components. Panels must be at an angle to be cleaned.

Method #3:  Static charge- By creating a positive static charge, dust will jump off of panels and windows or any piece of equipment that needs to be cleaned.  Positives: This method can be solid state and adds little mass to panels or rovers.  In Mar’s dry atmosphere, generating a strong static field won’t be hard.  A slight positive charge imparted on the panels all the time may prevent any build up in the first place.  Panels can be flat (such as on a rover's roof). Negatives: “Sticky” or moist dust may not repel from the charged surfaces. A charged surface can discharge unintentionally and may damage sensitive components.

Method #4:  Brush- A squeegee or windshield wiper-type arm to physically brush dust off of panels.  Positives: Brushing off dust can be very effective- especially when combined with any of the other proposed methods.  Occasional brushing can be performed by an astronaut as part of maintenance work. Panels can be flat. Negatives, adds complexity to design and mass.  Brushes and brush components will wear out.

To increase effectiveness, any of the four proposed panel cleaning methods could be combined one or more other methods with the exception of Methods 1 and 3.

[RonM]

Method #5: Compressed Air - blow dust off panels using a compressor. Similar to the cleaning events experienced by rovers caused by wind or dust devils.

[Ionmars]

Method #6: Wind/Location Certain locations on Mars have high deposition rates i.e.buid-up of dunes. OTOH other areas have wind conditions where dust is swept up by the wind. This natural method was discovered by exploration rovers having their solar panels cleared by wind. Locating the panels wisely may also be a preventive measure.

[sghill]

Method #5: Compressed Air - blow dust off panels using a compressor. Similar to the cleaning events experienced by rovers caused by wind or dust devils.

I thought about this, but it's only a partial solution that's also problematic due to the low ambient air pressure.  "Puffers" might be great for cleaning specific spots or crevices, but I can't see it being a more effective solution for cleaning a field of PV panels than a shaker or static methods.

Method #6: Wind/Location Certain locations on Mars have high deposition rates i.e.buid-up of dunes. OTOH other areas have wind conditions where dust is swept up by the wind. This natural method was discovered by exploration rovers having their solar panels cleared by wind. Locating the panels wisely may also be a preventive measure.

I like the prophylactic measure of good panel placement.  This thread is about more than panels though.  Think about windows, access door seals, etc.

[nadreck]

Method #5: Compressed Air - blow dust off panels using a compressor. Similar to the cleaning events experienced by rovers caused by wind or dust devils.

I thought about this, but it's a partial solution that's problematic due to the low ambient air pressure.  "Puffers" might be great for cleaning specific spots or crevices, but I can't see it being a more effective solution for cleaning a field of PV panels than a shaker or static methods.

Hmm rather than "puffers" what about automated drones that flew over the panels and the prop wash (or ducted fan wash) was what was used to clear them. I have serious doubts about the effectiveness of rotor craft or their equivalent to explore Mars because of the difficulty of the distance/power/weight ratios, but I think you could have short range electric ones that managed to clear dust that way.

[sghill]

Method #5: Compressed Air - blow dust off panels using a compressor. Similar to the cleaning events experienced by rovers caused by wind or dust devils.

I thought about this, but it's a partial solution that's problematic due to the low ambient air pressure.  "Puffers" might be great for cleaning specific spots or crevices, but I can't see it being a more effective solution for cleaning a field of PV panels than a shaker or static methods.

Hmm rather than "puffers" what about automated drones that flew over the panels and the prop wash (or ducted fan wash) was what was used to clear them. I have serious doubts about the effectiveness of rotor craft or their equivalent to explore Mars because of the difficulty of the distance/power/weight ratios, but I think you could have short range electric ones that managed to clear dust that way.

Certainly has the distinct quality of not being simultaneously cheap, simple, effective, or safe!

[RonM]

Method #5: Compressed Air - blow dust off panels using a compressor. Similar to the cleaning events experienced by rovers caused by wind or dust devils.

I thought about this, but it's a partial solution that's problematic due to the low ambient air pressure.  "Puffers" might be great for cleaning specific spots or crevices, but I can't see it being a more effective solution for cleaning a field of PV panels than a shaker or static methods.

The "puffers" would be mounted on an arm that would move from top to bottom. That does add some mechanical complexity like method #4, but there are no brushes to wear out.

For mechanical simplicity, method #2 would probably be the best, but vibrations might shake components loose and damage the panels.

From what we have seen with panels on Spirit and Opportunity, I don't think we have to worry about the dust being sticky.

[nadreck]

Method #5: Compressed Air - blow dust off panels using a compressor. Similar to the cleaning events experienced by rovers caused by wind or dust devils.

I thought about this, but it's a partial solution that's problematic due to the low ambient air pressure.  "Puffers" might be great for cleaning specific spots or crevices, but I can't see it being a more effective solution for cleaning a field of PV panels than a shaker or static methods.

Hmm rather than "puffers" what about automated drones that flew over the panels and the prop wash (or ducted fan wash) was what was used to clear them. I have serious doubts about the effectiveness of rotor craft or their equivalent to explore Mars because of the difficulty of the distance/power/weight ratios, but I think you could have short range electric ones that managed to clear dust that way.

Certainly has the distinct quality of not being simultaneously cheap, simple, effective, or safe!

How is it not safe?

[kdhilliard]

Here is a review article on the subject from four years ago: Review of Self-Cleaning Method for Solar Cell Array.
(Free PDF of complete article is available via link on top of this abstract page.)

~Kirk

[TripD]

I considered having small tanks that take in the atmosphere at night then become pressurized by daylight. Although somewhat simple, it would require a tank for a small amount of panels.

As RonM pointed out, the dust does not appear to be particularly sticky.  If the panels were framed such that they could be angled to catch the most sun, that might be a method by which to slough off accumulated dust.

As Ionmars stated, choice of placement would seem prudent.

[IRobot]

Method #2: Vibrator motor- A small motor with an off-set weight attached like in cell phones spins up and vibrates loose dust from panels and windows.  Positives.  This device is extremely simple and lightweight.  Would work very well on a rover or fixed array as a “dog shaker.”  Negatives: There are moving parts that can wear out. Mars dust may be sticky, and won’t fall off easily using a vibration method.  Also, the motor’s vibrations could potentially dislodge or loosen other components. Panels must be at an angle to be cleaned.

Just use a soundspeaker coupled to the panel.

[Ionmars]

A procedure that could be carried out by a robotic rover with manipulator arms:
    Method #1 -- Spray on "Windex," followed by
    Method #4 -- Side to side windshield wiper.

[Russel]

I assume the OP is thinking automated cleaning. Otherwise I'd suggest a feather duster

[TripD]

Wait.... do Martians do windows?

[kch]

Wait.... do Martians do windows?

It's hard to say ... probably a safe bet that at least a few of them still use CP/M ...

[A_M_Swallow]

{snip}
From what we have seen with panels on Spirit and Opportunity, I don't think we have to worry about the dust being sticky.

That is on dry Mars. When we start making water and carbon compounds the dust may become sticky.

We can assume the dust is not sticky for the first few years.

[MickQ]

The simplest, safest, most reliable and highest TRL of all ?

A broom and ME !

Mick.

[R7]

Method #4:  Brush

Sign of mostly male space geeks site; this is listed as fourth method to remove dust 

Used to be #1 ...

[MickQ]

Hey !  I'm not wearing a skirt.  The heels might be a problem too. ( You like my legs ? )

Mick.

[R7]

Hey !  I'm not wearing a skirt.  The heels might be a problem too. ( You like my legs ? )

Mick.

Consider the imagery notional, couldn't find picture of anyone holding feather duster while wearing MCP suit