Non-PV Solar Power

[morganc01]

i found a nice idea for alternate power generation using Fresnel lens, peltier cells and heat sink. coupled with a solar tracker you could produce power for survival. the light Intensity on earth is about 1300 W/m2 (1300 watts per square meter) of power, on mars its about 590W/m2 (590 watts per square meter) at noon when its most intense but if you used the solar tracker you would be getting that power all day.

Below is a rough and bad drawing of my idea, forgive the poor artist skills

[profit004]

It works.. but Peltier cells are notoriously inefficient... your looking at MAYBE 8% efficiency.

Inside of an RTG with a nuclear heat source in the frozen vacuum of space the efficiency is not crippling for an extremely low power application... However with solar power you would need almost 30 square meters of lens to make a kilowatt of power.  

30 square meters is "Freaking enormous"

You would also need some place to dump nearly 10 kilowatts of heat... That would require a monster of a radiator on mars.

If this was hooked to a Stirling engine you might be able to push about 30 percent after conversion which would be a better conversion ratio you could cut down the size of the lens some hopefully making it look less like a sail.

But honestly at this point any real space based endeavor would be using radio-isotopic decay as the heat source... A 10K nuclear source would only need to be maybe a foot or two compared with a 2 story monster lens that would need to be attached to a massive framework to make it move..

*average US power use per home/apartments is 1.24KW per hour.  That is without needing to scrub carbon dioxide or deal with temperatures 40 degree's below zero or smelt metal.   Our house uses about 4KW per hour when things are running.  I would expect a martian base to use significantly more.

*The International Space Stations Solar panels produce 32.8 kW of power.  I would expect this to be about the correct minimum amount of power a martian base would need if it had a smelting operation and a water hydrolysis system.

* The monster Fresnel lens though might be useful for smelting, you could partially concentrate the sun through a large window in the habitat and then use it as a heat source with another lens...  Probably would use mirrors instead though.

* here is a link to the ISS truss solar panels so you can see what kinda size we would also need if we were to really use solar power. *remember it would need to be 2 to 3x larger than this even!
http://www.siggi-exner.de/ISS-sonnensegel.jpg
(And here you can see the same point this picture was taken in the overall scheme of things)  Look to the complete right at the little white area in the middle of the solar panels.
http://www.daviddarling.info/images/Integrated_Truss_Structure.jpg
Or a high resolution shot of it a little later.
http://upload.wikimedia.org/wikipedia/commons/0/04/International_Space_Station_after_undocking_of_STS-132.jpg

[Hyper]

I think I will still vote for solar cells. The technology is heading to much higher effeciencies, I think the current 40% mark is a indicator that better things are comming. Multi layer multi frequency cells are on the horizion and I would like to believe we can get up to 60% in the near future. Having said that lets look at the maintenance of the solar array as a primary reason to use them. They last a long time and have no moving parts aside from the tracking mechanism and I think I read someplace there was a gas tube device that would heat in the sun and move the panel till it was in shade ... can't remember the source. At any rate the low cost of maintaining the solar panels will be worth having them. A permanent settlement will probably have a few options for power and I am sure solar will be in the mix.
Keep researching the ideas !!!!

[thedubman]

@morgan - great ideas there.
@Hyper- have to agree, you have to think not only of how future technology/research will effect how effective these tech's will be but also in a gaming scenario, pepole will want to have to do things. Theres no point to a game/sim if all power supplies/equipment works automatically 100% without human intrevention and without failure's- be a pretty uneventfull mission if that was the case.. 

[profit004]

I think I read someplace there was a gas tube device that would heat in the sun and move the panel till it was in shade ... can't remember the source.

The automatic flow tracking systems as they currently stand would not work on mars, they require freon-11 which is the same that they use with the drinking birds.  It only works in a very narrow temperature band.  While I am sure SOMETHING could be made to work on mars it would be untested technology.  They would probably use a simple motor and computer control. 

The motor allows an array to be tilted horizontal when it is windy, and it will allow for more precise tracking with FAR less weight.

On earth though they are really great and I would like some for my PV array.

[Hyper]

Another issue is transporting that much equipment to the planet vs what resources exist there and what equipment could we ship to manufacture the panels on Mars, the front end cost of the equipment would certainly offset the cost of manufacture on earth and launch to Mars... Find us a simple machine guys and gals... I'll send one there...

[profit004]

I think we could make low efficiency solar panels on mars out of the "Shake and bake" method

Basically tossing some wires onto a stiff heat resistant backing...  Put a little dopant down *IE some salts or something* and some silicon and melt the thing together.. Some company was doing it on the cheap.. but it produces relatively crummy cells and most of the cost on earth is the panel assembly not the cells themselves...

I wish I had a link to this tech but it was a 91 thing back when I was assembling my own array and have not kept up on it.

On mars... In theory... we would not need glass panels.. no rain.. and a little compressed atmosphere should clean them....

But then we are back to acre's of cells...

...

http://en.wikipedia.org/wiki/Stirling_radioisotope_generator I still really see as one of the better options..

That in a reactor version I see as the best... =/