7 ms·
This is assuming the oxygen is used once then somehow eliminated. In practice that exhaled oxygen, as CO2, would probably be absorbed by plants, e.g. food crop
by mkl 5y ago
This is assuming the oxygen is used once then somehow eliminated. In practice that exhaled oxygen, as CO2, would probably be absorbed by plants, e.g. food crops, and recycled into O2.
Also, smelting aluminium takes a lot of power. The Tiwai Point Aluminium Smelter [1] uses 13% of New Zealand's electricity to separate the aluminium and oxygen.
[1] https://en.wikipedia.org/wiki/Tiwai_Point_Aluminium_Smelter https://en.wikipedia.org/wiki/Tiwai_Point_Aluminium_Smelter
- Joeri 5y agoOn the plus side for power, on the moon solar panels can operate at maximum efficiency all day every day. Build a network that spans the circumference and you get a reliable power grid.
- CamelCaseName 5y agoI was curious, so I looked it up. Circumference of the moon: 10,921km Longest power transmission line: 2,543km (Belo Monte-Rio de Janeiro transmission line, Brazil) So it sounds quite feasible actually
- Reason077 5y ago> "So it sounds quite feasible actually" But even more so near the poles, where there's no need to build transmission lines around the entire circumference to access constant sunlight. Prime real estate for moonbases!
- simonh 5y agoThe tradeoff there is that due to the angle of incidence, for a given area of the moon's surface you get a lot less energy. That means angling your panels vertically and spreading them out very widely to capture the same energy as you would at the equator. Or build a huge solar panel wall as high as you can that rotates.
- BiteCode_dev 5y agoThere is no wind and weak gravity, so you can build high.
- kreeben 5y agoStop tickling my imagination like that. It's not fair to a person who's almost 50.
- rootsudo 5y agoI enjoy this conversation - all the limitations we're used to on earth - no longer apply. It's pretty amusing. What if the moon was just a mining and energy "moon" how amusing would that be.
- dustintrex 5y agoUnfortunately there are a whole host of new limitations, some obvious (no atmosphere) and some less so (moon dust is super abrasive because there's no wind or water to file it down).
- dylan604 5y agoThink of the extra-global supply chain disruptions that are possible though. We're talking easier to disrupt than a ship going sideways through a canal.
- BiteCode_dev 5y agoAlso radiations, temperature variations, and space dinosaurs. But it's still fun to think about it.
- rbanffy 5y ago> for a given area of the moon's surface you get a lot less energy Without atmosphere, you just point the panel to the sun and you'll get 100% power again regardless of how low the Sun is over the horizon.
- hoseja 5y agoI imagine installing superconducting grid might be feasible, too.
- chii 5y agolike a mathematician, anything that is theoretically proven is considered trivial.
- mkl 5y agoIf you're transmitting around the night side you could use the extreme cold to help with that. Transmitting when the sun is shining on your grid is another story.
- politician 5y agoYou could build some pretty impressive Stirling engines with the heat difference between the light and dark sides.
- Reason077 5y agoPRO TIP: locate your moon-base near the lunar poles where this is significantly easier/cheaper!
- Retric 5y agoThe pools get months long night just line on earth. You would need to build a mega structure with rotating panels or have serious batteries.
- Reason077 5y agoThe moon only has a 1.5 degree axis of tilt, so unlike on earth (23.5 degree tilt!) the seasons aren’t super pronounced. It’s true that there are still short periods of darkness even at the poles, but they’re not months long like on Earth. Further, you could still access 24 hour sunlight by building a transmission grid with multiple solar panels, but the length of the transmission lines required would be much shorter near the poles.
- Retric 5y agoHere’s an actual visualization of the moons South Pole, a few points might not see months long full dark, but 99% of the area ends up in shadow several weeks. And that scales up to some areas being full dark throughout the year. https://svs.gsfc.nasa.gov/4770 https://svs.gsfc.nasa.gov/4770 Of course this means seriously low temperatures as in below negative 150 range. https://svs.gsfc.nasa.gov/Gallery/moonpole.html https://svs.gsfc.nasa.gov/Gallery/moonpole.html
- Reason077 5y agoDeep craters aside, the lunar poles get the most sunshine of any points on the moon. Lunar "night" lasts ~29.5 earth days at the equator, but much less, on average, at the poles. You get similarly extreme cold temperatures (-180C or so) anywhere on the moon during darkness, even at the equator.
- willis936 5y agoThere is also an abundance of He3 in the upper crust of the moon. You could centrifuge that out and use it to fuel a D-He3 fusion reactor (assuming you could make such a reactor work terrestrially, ship millions of tons, and assemble such a facility on the moon). D-He3 is the lowest temperature aneutronic fusion reaction. Not all fast neutron hardening problems go away because a small cross section of reactions will be D-D even at the higher temperature (and potentially short bursts of higher fast neutron flux if temperature control is inadequate and low). However, most of the energy comes out as fast charged particles, which is open to direct conversion. Ditching the steam cycle is a big deal in terms of plant size and weight.
- imglorp 5y agoAnother plus, you don't need electricity to make a solar reflective furnace. The lower gravity would be helpful building a field of reflectors or a large arecebo-like dish in a crater.
- Retric 5y agoThe moon is a terrible place for solar power. Solar panel efficiency drops by about 0.5 percent per degree Celsius over 25C, which is a real issue when the moons daytime temperature hits 110C (230f) Aka past the boiling point of water. The day night cycle is almost a month long which means you need extreme energy storage, but daytime temperatures go from colder than the arctic winter to past the boiling point of water. The poles don’t get as hot, but they also get months long night due to the moons axial tilt.
- geoduck14 5y ago>Solar panel efficiency drops by about 0.5 percent per degree Celsius over 25C, which is a real issue when the moons daytime temperature hits 110C (230f) Aka past the boiling point of water. Don't they already handle these extremes in satellite solar panels?
- Retric 5y agoThe back of solar panels are to the void of space. On the moon it’s to the moon’s surface which might initially be cold but would warm over time.
- jjk166 5y agoJust align your radiators vertically so their flat surfaces point towards the horizon (ie the void of space). Actually you'd want to slightly angle them such that they are still pointing towards empty space but not at the next radiator over, but still you get the idea.
- Retric 5y agoThere are many possible solutions but they all add weight, complexity, and or inefficiency. For example further from the equator the lower the daytime temperature, but also directly translates into a lower subsurface temperature which has it’s own problems for a lunar colony.
- 5y ago
- anthony_r 5y agoYeah, that's what I don't get: if you're going to invest effort and energy into reversing the oxidation of some element, why not choose carbon and decompose CO2? It will require non trivial amounts of energy either way.
- mkl 5y agoThere is very little CO2 on the moon, so that's not really an option.
- rendall 5y agoHumans, livestock and industry will introduce it.
- politician 5y agoIt’s better to get a metal for the effort.