Caltech scientists will launch a space-based solar power satellite on Tuesday. The plan is to build a power station in orbit around the Earth which would beam energy back to the ground where it can be incorporated into the grid. Good thing about space solar? The sun is always shining up there.
The demonstrator mission, SSPD, will test three key elements of the satellites, including the photovoltaic cells and the unfurling mechanism. #Science
So they're experimenting to build an orbital system, that could send a high energy beam to almost any point on earth.
WHAT. COULD. POSSIBLY. GO. WRONG?
While there's plenty of space down here to collect, store, transform and transport the 10000 times more solar energy than the whole earth needs, with well-known & in comparison inexpensive technology 🤦
(But that would probably not be sponsored by military sources, I guess)
1) you'll need _many_ of those satellites for commercial scale.
Each with a beam of >200W/m2 (in normal operation) with a phase controlled (=highly steerable) antenna.
How many beams would you need to fry electronic infrastructure incl satellites, kill living things, make an area unpassable?
(hint: their paper speaks of up to 80% loss by atmospheric water)
And that's not calculating the effects on weather etc of those 80% energy in "normal" operation.
2) Efficiency will depend on weather down here, esp water in the atmosphere. I.e. heavy rain, snow = a _lot_ of power loss. You'll need storage capacity and a flexible power grid.
BTW: 200W/m2 is what todays solar cells collect on any roof top, parking lot or covered bike lane, while the area below and around is still usable. (You'll need storage anyway, see above)
PV _is_ the cheapest form of el. power now.
https://www.solarfeeds.com/mag/netherlands-unveils-worlds-first-solar-bike-lane/
2) PV efficiency on earth depends on weather to! PV is cheapest yes AND could be cheaper (perhaps) if operating in orbit. Daytime 90% instead of 50%, no clouds, can stay oriented with sun. No need to embed the cells in glass and steel and concrete them down.
SBSP would just be pure PVs in space, with launch cost to get them there and transmission cost back to earth via MW. The efficiency tradeoffs may or may not be net beneficial environmentally. Worth researching.
The rectennas would have to withstand the same weather conditions as PV.
They'll need the same infrastructure for transformers, switches, etc.
And they will need more space on the ground, if the energy density of the beam on the ground is less than 200W/m2.
(the more off the equator the rectenna is, the more space you'll need)
I'll give you the continous delivery - although clouds, rain and snwo will absorb a lot, so the output will also vary with the weather.
Yes to all that, the ground side will have to be wired in and cope with weather etc just like PV stations. Engineering a rectenna that's both robust enough and lightweight enough to make the whole thing worthwhile would be one of the main challanges (the other being similar research/engineering on the space side). It's highly uncertain whether it would work out.
But at this point we're a long way from "WHAT. COULD. POSSIBLY. GO. WRONG?", right? Let's wait for the research.
Jack Ryan
Jaddy
Carl Brusse