Charlie Stross says Elon Musk is trying to corner the market for space-based solar power.

Musk owns Tesla Energy. And I think he’s going to turn a profit on Starship by using it to launch Space based solar power satellites. By my back of the envelope calculation, a Starship can put roughly 5-10MW of space-rate photovoltaic cells into orbit in one shot. ROSA—Roll Out Solar Arrays now installed on the ISS are ridiculously light by historic standards, and flexible: they can be rolled up for launch, then unrolled on orbit. Current ROSA panels have a mass of 325kg and three pairs provide 120kW of power to the ISS: 2 tonnes for 120KW suggests that a 100 tonne Starship payload could produce 6MW using current generation panels, and I suspect a lot of that weight is structural overhead. The PV material used in ROSA reportedly weighs a mere 50 grams per square metre, comparable to lightweight laser printer paper, so a payload of pure PV material could have an area of up to 20 million square metres. At 100 watts of usable sunlight per square metre at Earth’s orbit, that translates to 2GW. So Starship is definitely getting into the payload ball-park we’d need to make orbital SBSP stations practical. 1970s proposals foundered on the costs of the Space Shuttle, which was billed as offering $300/lb launch costs (a sad and pathetic joke), but Musk is selling Starship as a $2M/launch system, which works out at $20/kg.

antipope.org

It just makes sense that you could intercept enormous amounts of solar energy in space and beam it down somehow. The sun is so unimaginably vast that only a miniscule fraction of its energy ever strikes the Earth. If you can position solar panels in orbit so they are not shading the Earth, it seems like there would be no practical limit to how much energy you could gather. Then you have the problem of beaming it down. The engineers who look into this assure us that it can be done at a low enough intensity that we would experience only a pleasantly warm sensation if you happened to walk through the beam, and they can do it in the middle of nowhere so that doesn’t even happen. Of course, members of the public are likely to be very skeptical of this if and when it does happen. Still, if most people are skeptical, a small country or multi-national corporation or two could create a nice carbon-free heavy industry setup and either out-compete or charge everybody else to use it.