[X] My Assistant

[SpaceListener]

The new technology to generate electricity by recycling the water between day and night looks very promising. I tought it would be good to share us. It is ideal for Moon South Polar where the night time is shorter than the day by an proportion of 1/3.

Click here for more info

The alternative generation of the electricity would be a solar panel on the crest of mountain where the lunar post would be located in a permanent dark place. Let see what technology would be winner: Solar panel or Fuel Cells.

[Phil Stooke]

Any sensible design would include both for complete redundancy.

Phil

[SpaceListener]

I think that the solar panel is simpler and robuster than the fuel cell.

The two matters to worry with the solar panel is
1) Try to point directly constant to Sun according to the Moon orbit around the Earth. However, it would be solved by puting 12 solar panels, one panel for every 30 degree difference.

2) The other risk with solar panel is by the metorite impact.

About the fuel cell, I don't know much about its risks except to bring water to Moon or find water in Moon. Up to now, there is not certain about the existence of water in Moon. Hope, it will be soon that we are going to know about the confirmation of existence of water on the Moon.

Does anyone know which spacecraft is aimed to confirm about the existence of water in Moon: Kaguya, Change, Chandrayaan, LCROSS and LRO? This will lead to increase the possibility to use fuel cell.

[djellison]

I think that the solar panel is simpler and robuster than the fuel cell.

And when it's dark?

[SpaceListener]

And when it's dark?

Inside of one of the South Pole craters where the sun light never reach. Well, the electricity for lunar post is needed for any time.

[lyford]

Maybe the solar panels were specially developed for this mission, Doug?

[Guest_Zvezdichko_*]

I see nothing about nuclear power. Why?

[Del Palmer]

Let see what technology would be winner: Solar panel or Fuel Cells.

You need both. A fuel cell is like a battery: it just stores energy. It would be useless without solar cells to 'charge' it up.

[mchan]

A fuel cell produces electricity as long as there is "fuel" to consume. So if the fuel cell reactants are re-supplied from Earth, you would continue to get electricity.

I also think nuclear should be considered. A reactor is compact and has high power levels relative to solar and fuel cells if you're really talking about lighting up the lunar night.

[djellison]

A fuel cell produces electricity as long as there is "fuel" to consume. So if the fuel cell reactants are re-supplied from Earth, you would continue to get electricity.

Have your read the article at the start of this thread? When a fuel cell is used, you get water. With the solar power you re-split the water and refill your fuel tanks.

"Nothing goes in and nothing comes out, other than electrical power and waste heat. The hydrogen, oxygen and product water inside are simply recycled over and over again."

Doug

[mchan]

D'oh. Lost the context.

[SpaceListener]

You need both. A fuel cell is like a battery: it just stores energy. It would be useless without solar cells to 'charge' it up.

Yes, agree, as Phil has said, for a greater survavility, the key is the redundancy.

However, a solar panel on the crest of some high mountain of South Pole, not 100% sure since there are few mountains around S.P. might be, will be always exposed by the sun light in the round lunar orbit. So it is no needed to use the battery. However, I prefer to have both kind of power supplies and two independent circuits at the hand for just in the case if the circuitry of solar panel might get troubled after a very rare micrometeorit impact. Without electricity in the Moon, everybody will be dead by not having a proper A/C or heating, oxygen and water recycle filtering and etc.

Does the SMART-1 and other lunar probe has already identified an South Pole's montain in which crest is always exposed to the sun in all round lunar orbit? If not, maybe, the present probes around moon will be able to identify which ones?

[dvandorn]

It's not a matter of redundancy. What is being proposed is to use fuel cells as an energy storage system.

Every energy process involves several systems -- collection, storage and distribution being the primary systems. In the proposed process, solar panels are used to collect energy. The energy from the solar panels goes into cracking water into hydrogen and oxygen -- this is a way of storing the solar energy, since the separated hydrogen and oxygen are now fuels for a fuel cell system. You use those fuels on demand to provide power into the distribution system, which delivers it to the people and equipment that need it.

Less sophisticated energy processes, like those used on the ISS, for instance, simply use rechargeable batteries to store the power being collected by solar cells. The problem is that batteries eventually wear out and have to be replaced. In the solar-to-fuel-cell scenario, your energy storage doesn't wear out. (It may need some maintenance as time goes on, but the main elements of energy storage, the reactants, never wear out, they are just re-used over and over again.)

Since the solar panels and the fuel cells are serving very different functions in this energy process, it's not really a redundant system. If you lost the fuel cells, you'd have to replace them with batteries for energy storage, and if you lost the solar panels, you'd have to replace them with some other energy source (nuclear?) to crack the water back into hydrogen and oxygen and recycle the storage system's storage medium. In true redundancy, one element could take over for the other without impact to the overall system.

-the other Doug