Blue Origin Making Solar Cells from Lunar Regolith

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Since 2021, Blue Origin has been making solar cells and transmission wire from regolith simulants. Using regolith simulants, their reactor produces iron, silicon, and aluminum through molten regolith electrolysis, in which an electrical current separates those elements from the oxygen to which they are bound. Oxygen for propulsion and life support is a byproduct.

Above – Molten regolith electrolysis extracts iron, then silicon, and finally aluminum by passing a current through the molten regolith. The rising oxygen bubbles in one of our reactors show metals and metalloids being separated from oxygen. Our reactor geometry, metal extraction approach, and materials selection will enable sustained lunar operations.

This process purifies silicon to more than 99.999%. This level of purity is required to make efficient solar cells. While typical silicon purification methods on Earth use large amounts of toxic and explosive chemicals, their process uses just sunlight and the silicon from their reactor.

The harsh lunar environment means lunar solar cells need cover glass. They would only last for days without glass. This technique uses only molten regolith electrolysis byproducts to make cover glass that enables lunar lifetimes exceeding a decade.

Blue Origin’s goal is to produce solar power using only lunar resources.

32 thoughts on “Blue Origin Making Solar Cells from Lunar Regolith”

  1. Combine 3D printing with AI and this tech, sprinkle in a genetic algorithm, and it could evolve into the replicators in Stargate! SOOOO SCARY! ; )

    On a more serious note, this is good tech to enable moon industrialization to build space solar geoengineering infrastructure. And the scare mongers scary “Termination Shock” name is really not an issue.

  2. Probably not going to be used, as manufacturing them on earth will be cheaper and thanks to spacex, exporting them off world will be too.

    • True, that. FOR AWHILE.

      Once some critical ‘mass of spacefarers’ (AKA moonpeople) is achieved, then it will definitely make more sense to make ’em in-situ. Especially since limitless amounts (kind of an oxymoronic wording) of vacuum is available on the Moon’s surface.

      Just a matter of time.
      and money.
      GoatGuy

    • Could … not actually an unwarranted idea at all. The real ‘trick’ with reflectors though is to handle the 1366 watts per m^2 of really-really broad spectrum solar irradiation competently. Not like the garden variety solar field landing on ol’ Planet Dirt, all nicely filtered and de-radiation-ized by the atmosphere.

      Lots and lots of UV on Luna.

      But still … its a decent idea. Might be best to have a maker-factory specialized to the task of taking regolith and pressing it into hyperbolics, then blazing their surfaces to molten while spinning, then (hey the vacuum is free) sputtering them with alternating layers of high and low index-of-refraction non-metals, to build up a broad-spectrum dichroic front surface mirror.

      Hyperbolics work well to focus off-center.

      Yet … just sitting here thinking, i guess the real problem is that Sol ‘apparently’ rotates around Luna every 28 days or so. The fixed-in-a-depression mirrors suck then.

      Maybe ‘hmmm… more engineering required’
      GoatGuy

      • Yes, reflectors would be easier to make from the lunar materials; you just need to polish some metal. Also, if the metal “only” reflect 80%, that would be fine.

        You can then use solar cells from earth in the focus point of the reflectors. At 100 solar intensity, you would need much less solar cells, and they could be sent from earth at a reasonable cost. Of course you would need cooling of the solar cells with fins, which would increase the cost, but hopefully not to the point of making it more expensive than using “regular” solar cells.

  4. How much of a problem would it be, having that regolith purifier be on for two weeks, then off for two weeks?
    I would expect the melt to freeze during the lunar night unless there is some non-solar energy supply available.

  5. I hate to rain on the parade, but silicon solar cells are almost exclusively made from single crystal silicon. The means that in addition to having the silicon furnace, they would need a CS reactor, doping equipment, deposition equipment etc. The silicon furnace is just a tine part of it. And the doping chemicals etc must all be brought from Earth…

    Oh, and by the way, to make silicon wafers, you need 99.9999999 [1] purity, not 99.999. They must reduce the amount of impurities by a factor of 10000, it would seem…

    https://www.pnas.org/doi/pdf/10.1073/pnas.1513012112
    https://sinovoltaics.com/learning-center/solar-cells/silicon-si-solar-cells-produced/

    • I think you’re confusing the level of purity needed for solar cells with the level of purity needed to get a good yield when producing high gate count processors.

      For the longest while, solar cells were made from the same level of purity, because they were a small market, that didn’t justify producing a separate stream of production for. But they don’t actually require the same number of “nines”.

      It’s true that you lose a bit on efficiency by dropping the number of “nines”, but the cells are not nearly as sensitive as digital logic chips, which are scrap if one gate is bad.

      • Interesting. Could you provide a source for the lower requirement on Si for solar cells? The sources I listed above states the more stringent requirements, but that may be out of date. Also, would 99.999% fulfill the lower requirements that you refer to?

    • I thought they were the “export heavy industry to space to preserve Earth,” so that checks out.

      Good on Jeff. He’s doing something useful besides delaying the delivery of those engines (sure, the first two arrived, but what about the next two? Vulcan Centaur is expendable…)

    • No, they are an O’Neillian company. Rockets are only a means to that end. O’Neill envisioned the establishment of a lunar base in order to produce the metals to produce a mass driver to launch said metals and regolith to L5 to produce a huge, spinning colony. That is why Blue’s rocket is lunar and why they are working on extracting metals from regolith.

      Blue isn’t even fundamentally driven by the profit motive. They continue forward while losing money each year. Getting government and commercial contracts is helpful but not essential given the wealth of Bezos.

  7. It’s neat that they are working on this, but to me they should be more focused on actually becoming a real business.

  8. So, after they cover the Moon in solar panels, will it look like a giant disco ball?

    “Stayin’ alive, stayin’ alive….”

      • maybe it starts a circle of panels and/or concentrating solar with parallel enforced cable net structures for a ~9000km ring on ~55° north (maybe it’s called ‘rolling release’)? What km/d would be imaginable or reasonable (given 1km/d, ~50m/hr, it’s a ~25yrs project)?

  9. I’d just like to say this sounds awesome.

    How much energy is needed, and how much would materials cost if one used this method on earth?

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