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For a given mass of solar panels, the space version is perhaps 50% more efficient, due to the fact they operate in space. Putting them there, in the most optimi

For a given mass of solar panels, the space version is perhaps 50% more efficient, due to the fact they operate in space. Putting them there, in the most optimistic scenario, will cost perhaps 100x versus the ground level version. Currently it's something like 1000x, but let's asume prices go down due to Starship and what not. So you really have to ask what kind of practical scenario affords you to use energy that is at least 60 times more expensive than what is available at ground level (but more realistically, at least 300-400x). Even if you include the capital cost of Li-ion batteries, their wear and tear and road transport for over 1000 miles, you can still get power much cheaper by just trucking batteries around. That, mind you, is before any transmission loses, investment in ground infrastructure etc., it makes no sense to put solar panels in space because the efficiency gains are simply too limited. This leaves the military scenario indeed - which is basically sci-fi, but bras has been known to abandon common sense when planning technology, see the initial Space Shuttle concept, space laser weapons etc.

DennisP 4y ago
People drastically underestimate how Starship will change launch costs. Right now they throw away an expensive upper stage with every launch, and even the lower stage only gets used about a dozen times. Starship doesn't throw away anything and it's designed to be used about a thousand times. At scale it's basically just the cost of fuel and ground services, which drops cost by a couple orders of magnitude. The book The Case for Space Solar Power has detailed cost estimates for NASA's SPS-ALPHA design. It was published about a decade ago so has old launch costs. I plugged in Starship costs and got a total cost of $0.04/kWh, which is pretty great for dispatchable power without needing storage.
- kiba 4y ago
  The real money comes from using starship to develop spaced based industrial capacity. Instead of manufacturing solar panels on earth, it would be manufactured in space. Once we have real space industry, doing things in orbit would be much cheaper.
  - deleted 4y ago
    [deleted]
  - danans 4y ago
    > Instead of manufacturing solar panels on earth, it would be manufactured in space. Once we have real space industry, doing things in orbit would be much cheaper. The raw materials would still need to be shot up into space. And what makes manufacturing and assembly in zero-g cheaper than on the Earth's surface?
    - r2_pilot 4y ago
      The idea is probably using ISRU(in-situ resource utilization) with regards to local asteroids to save on launch costs. Manufacturing/assembly would likely be more expensive at first until the techniques and technologies are learned(perhaps one could upsell this as "truly green manufacturing" since there would be no environmental byproducts to affect Earth).
      - danans 4y ago
        > perhaps one could upsell this as "truly green manufacturing" since there would be no environmental byproducts to affect Earth Except for the massive byproducts created on earth to get through the "more expensive" phase. It would be deeply deceptive and cynical to sell that as "green", surpassing even today's deceptive selling of carbon capture and storage technology on fossil fuel power plants.
        DennisP 4y ago
        Starship uses methane fuel. Make that from water and ambient CO2 using clean energy sources, and the environmental impact of launch will be minimal. Fuel is a pretty small cost for rockets anyway so using more-expensive clean fuel wouldn't be prohibitive.
        Nomentatus 4y ago
        But less and less is launched per pound of space-produced product as time goes on, until only rare complex (small) components such as microprocessors come from earth. There will be an industrial chain taking aluminum from lunar regolith that's catapulted out to a Lagrange point and then the raw aluminum or printed products will be lowered to more suitable orbits by ion engines that spit out ions from lunar soil. Hate to be the one to mention it, but the military may well be paying most of the freight to set most of this up (covertly or not) since space based you-name-it including hypersonic projectiles are going to be more and more useful as the decades pass.
coryrc 4y ago
In space they generate ~7x as much power averaged over the day (24hr sunlight, plus full power all the time) and during the winter in the upper latitudes it has got to be at least 100x the power you get from one on the ground.
- manholio 4y ago
  > 24hr sunlight That means you either need to sync the satellite with the Earth's rotation (Sun synchronous orbit), so you will deliver power at the exact time the corresponding Earth region has full sunlight (and thus, a surplus), or that you will have to go at insane altitudes. Or that you would need to launch some sort of orbital power ring that can transport the energy around the world. Good-luck beaming power from SSO or across spans of thousands of miles. First let's see a phone that charges from across the room with no matter how bad efficiency, or an electric car charging wirelessly on the go.
  - Nomentatus 4y ago
    The US military has already made a space-based test of power transmission from orbit via microwave (hundreds of miles down). Dunno if they published the results, possibly not.
  - Schroedingersat 4y ago
    > Good-luck beaming power from SSO or across spans of thousands of miles. First let's see a phone that charges from across the room with no matter how bad efficiency, or an electric car charging wirelessly on the go. This is the actual impetus behind the push. Much like nuclear, the militaries of the world want a new toy (focused beam weapon), but want to pass the buck to the civilian population and claim that it's abundant cheap power with no risks.

DennisP 4y ago

People drastically underestimate how Starship will change launch costs. Right now they throw away an expensive upper stage with every launch, and even the lower stage only gets used about a dozen times. Starship doesn't throw away anything and it's designed to be used about a thousand times. At scale it's basically just the cost of fuel and ground services, which drops cost by a couple orders of magnitude. The book The Case for Space Solar Power has detailed cost estimates for NASA's SPS-ALPHA design. It was published about a decade ago so has old launch costs. I plugged in Starship costs and got a total cost of $0.04/kWh, which is pretty great for dispatchable power without needing storage.

kiba 4y ago
The real money comes from using starship to develop spaced based industrial capacity. Instead of manufacturing solar panels on earth, it would be manufactured in space. Once we have real space industry, doing things in orbit would be much cheaper.
- deleted 4y ago
  [deleted]
- danans 4y ago
  > Instead of manufacturing solar panels on earth, it would be manufactured in space. Once we have real space industry, doing things in orbit would be much cheaper. The raw materials would still need to be shot up into space. And what makes manufacturing and assembly in zero-g cheaper than on the Earth's surface?
  - r2_pilot 4y ago
    The idea is probably using ISRU(in-situ resource utilization) with regards to local asteroids to save on launch costs. Manufacturing/assembly would likely be more expensive at first until the techniques and technologies are learned(perhaps one could upsell this as "truly green manufacturing" since there would be no environmental byproducts to affect Earth).
    - danans 4y ago
      > perhaps one could upsell this as "truly green manufacturing" since there would be no environmental byproducts to affect Earth Except for the massive byproducts created on earth to get through the "more expensive" phase. It would be deeply deceptive and cynical to sell that as "green", surpassing even today's deceptive selling of carbon capture and storage technology on fossil fuel power plants.
      - DennisP 4y ago
        Starship uses methane fuel. Make that from water and ambient CO2 using clean energy sources, and the environmental impact of launch will be minimal. Fuel is a pretty small cost for rockets anyway so using more-expensive clean fuel wouldn't be prohibitive.
      - Nomentatus 4y ago
        But less and less is launched per pound of space-produced product as time goes on, until only rare complex (small) components such as microprocessors come from earth. There will be an industrial chain taking aluminum from lunar regolith that's catapulted out to a Lagrange point and then the raw aluminum or printed products will be lowered to more suitable orbits by ion engines that spit out ions from lunar soil. Hate to be the one to mention it, but the military may well be paying most of the freight to set most of this up (covertly or not) since space based you-name-it including hypersonic projectiles are going to be more and more useful as the decades pass.

coryrc 4y ago

In space they generate ~7x as much power averaged over the day (24hr sunlight, plus full power all the time) and during the winter in the upper latitudes it has got to be at least 100x the power you get from one on the ground.

manholio 4y ago
> 24hr sunlight That means you either need to sync the satellite with the Earth's rotation (Sun synchronous orbit), so you will deliver power at the exact time the corresponding Earth region has full sunlight (and thus, a surplus), or that you will have to go at insane altitudes. Or that you would need to launch some sort of orbital power ring that can transport the energy around the world. Good-luck beaming power from SSO or across spans of thousands of miles. First let's see a phone that charges from across the room with no matter how bad efficiency, or an electric car charging wirelessly on the go.
- Nomentatus 4y ago
  The US military has already made a space-based test of power transmission from orbit via microwave (hundreds of miles down). Dunno if they published the results, possibly not.
- Schroedingersat 4y ago
  > Good-luck beaming power from SSO or across spans of thousands of miles. First let's see a phone that charges from across the room with no matter how bad efficiency, or an electric car charging wirelessly on the go. This is the actual impetus behind the push. Much like nuclear, the militaries of the world want a new toy (focused beam weapon), but want to pass the buck to the civilian population and claim that it's abundant cheap power with no risks.