3 ms·

> Add the embodied energy of the other components in space and on the ground, and I could easily believe we get to a year payback—now bringing the total (manufa

> Add the embodied energy of the other components in space and on the ground, and I could easily believe we get to a year payback—now bringing the total (manufacture plus launch) to two years and an EROEI around 10:1. > If my 100× light-weighting proves to be unrealistic, and we can only realize a factor of ten improvement over our rooftop panels, the solar panel launch cost climbs to three years, so that adding other components results in perhaps a 4:1 EROEI. > In the end, the EROEI is not as prohibitive as I imagined: it’s not a net energy drain as I might have feared. But it’s not obviously better than conventional solar either. His overall conclusion may reach that conclusion, but his EROI give SPS a net 10:1 to 4:1 energy returns even in his worse case. So regardless if its cost competitive to ground based arrays or not, it might have uses and would likely result in net energy gain vs input (including materials).

Dylan16807 5y ago
It's like saying I could drive 80 miles each way to a gas station despite there being dozens of options within 5 miles. I get more energy than I spend, but it's never worth it. Also the gas there is extremely expensive.
- elcritch 5y ago
  Even in your example there are scenarios it could be worthwhile. What if it’s gas produced in-country and its used as a military fill station? Particularly if it’s always available despite foreign political events. For personal usage maybe it’ll never be worth it, but perhaps it’s worthwhile for other use cases. Solar + batteries might not work if you can’t buy/procur enough batteries, especially for Arctic regions say where days are short. Or perhaps it’ll become possible to use for recharging electric airplanes in-flight. In that case the ability to “beam” worldwide might offset the cost of ground based grid of towers or ocean barges, etc. To be clear, I think it’s very unlikely, just not infeasible. Particularly if antennae tech keeps improving.
  - Dylan16807 5y ago
    > What if it’s gas produced in-country and its used as a military fill station? Particularly if it’s always available despite foreign political events. Except local solar requires fewer resources of every kind than satellite solar. You're more likely in every way to get cut off from the space version. > Or perhaps it’ll become possible to use for recharging electric airplanes in-flight. In that case the ability to “beam” worldwide might offset the cost of ground based grid of towers or ocean barges, etc. That would be cool. But it's a very different problem from grid power. I don't think it counts as a reason to beam dedicated space power to ground stations.

Dylan16807 5y ago

It's like saying I could drive 80 miles each way to a gas station despite there being dozens of options within 5 miles. I get more energy than I spend, but it's never worth it. Also the gas there is extremely expensive.

elcritch 5y ago
Even in your example there are scenarios it could be worthwhile. What if it’s gas produced in-country and its used as a military fill station? Particularly if it’s always available despite foreign political events. For personal usage maybe it’ll never be worth it, but perhaps it’s worthwhile for other use cases. Solar + batteries might not work if you can’t buy/procur enough batteries, especially for Arctic regions say where days are short. Or perhaps it’ll become possible to use for recharging electric airplanes in-flight. In that case the ability to “beam” worldwide might offset the cost of ground based grid of towers or ocean barges, etc. To be clear, I think it’s very unlikely, just not infeasible. Particularly if antennae tech keeps improving.
- Dylan16807 5y ago
  > What if it’s gas produced in-country and its used as a military fill station? Particularly if it’s always available despite foreign political events. Except local solar requires fewer resources of every kind than satellite solar. You're more likely in every way to get cut off from the space version. > Or perhaps it’ll become possible to use for recharging electric airplanes in-flight. In that case the ability to “beam” worldwide might offset the cost of ground based grid of towers or ocean barges, etc. That would be cool. But it's a very different problem from grid power. I don't think it counts as a reason to beam dedicated space power to ground stations.