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Comment by phreeza | Hacker News Reader

How would such a settlement meets its energy needs? How do you bootstrap an industrial civilisation without fossil fuels? My guess would be that the time to amortise a solar cell is quite long because of the distance from the sun, and wind is also not very viable because of the thin atmosphere. So that really only leaves nuclear?

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From the article:

"Copious and reliable electrical power will be required on Mars, provided most likely by a nuclear fission plant(s) or solar, but is beyond the scope of this discussion."

Ha thanks. I searched for "energy" to make sure I hadn't missed it, but forgot to check for "power" :-D

Problems are defined as beyond the scope of this discussion, therefore this plan has no problems.

Nuclear RTGs are a reasonable solution for power generation in the kW range if you could have a bank of them. The benefits are that they're not particularly radioactive (when enclosed) and they also generate copious amounts of heat as a byproduct. I think one is used in the Martian?

https://en.wikipedia.org/wiki/Radioisotope_thermoelectric_ge...

Sure, but I think if we are talking about 10^6 people as the article does, the energy needs will be on the order of several GW at least...

The main thing I'm thinking about is robustness and lack of maintenance. One advantage of RTGs is that you could distribute power wherever it's needed. RTGs are essentially maintenance free (decades) over the lifetime of the fuel.

There are suitcase-sized power plants that NASA have proposed, but I have no idea how feasible they are - or what the maintenance requirements are. I've not been able to find any actual papers on the subject, just the usual gushing science press. Safety seems to be OK, but these are incredibly complicated systems requiring liquid metal cooling (for a start).

I don't know why you would use an RTG instead of conventional fission reactors.

Yea, each A4W reactor on a Nimitz class aircraft carrier can produce on the order of 100MW electricity, and the fuel rods last about 25 years. So if you can scale those down sufficiently (maybe use in situ materials for shielding?), getting to the GW range doesn't seem as far off as I had initially suspected.

Solar works fine. That's probably the first product they should become self sufficient making.

And batteries, or more generally energy storage.

Mars is about 1.5 AUs from the Sun, so light intensity (and solar power) is about (1/1.5)^2 = 44% that of Earth. That doesn't rule out solar power, but it does make alternatives relatively more appealing.

One partial source might be the burning of biomass (e.g. potato leaves and, um, other things).

That compares solar panels in orbit around Mars and Earth. How much do we lose on Earth with our thick atmosphere, ozone layer, and clouds?

I don't think burning anything for energy is going to be an option. Oxygen isn't free.

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