5 ms·
Yeah, no night, no atmosphere, constant power output, lot's of real estate, and panels in space do not need heavy superstructure to withstand weather or gravity
by Faint 3y ago
Yeah, no night, no atmosphere, constant power output, lot's of real estate, and panels in space do not need heavy superstructure to withstand weather or gravity, thus they could potentially be extremely light for the area (micrometers to tens of micrometers thick at most needed for light absorption). And in far future, if they are built of materials taken from moon or meteorites, you could also bypass most of the lifting cost for even that. Of course, that would need huge scale to justify the R&D to pull it off.
Anyway, space based solar power is the end game. Nothing on earth will ever provide the quantities of power (not even nuclear, fusion or fission) that capturing solar energy can.
- sandos 3y agoConclusion: everyone will eventually live in orbit!
- XorNot 3y agoI mean probably? We can't manufacture more real estate down here as easily as you could up there (once certain technologies are common place).
- ZeroGravitas 3y ago> constant power output Worth noting this isn't as much of a benefit as it's made out to be. If you were designing a perfect power source, it would match demand, so produce more in winter in polar regions, and more in summer for regions with lots of AC. Similarly, you'd generally want more power during the day than at night. This is part of the reason a mix of solar and wind that varies by latitude is an ideal mix. Space power might get more bang for buck if it could target its power to different regions e.g. swapping from north to south as the seasons change, and/or following the day/night cycle and/or weather to maximise energy price.
- DennisP 3y agoThe satellites would be in geostationary, with phased-array transmitters, focused by a reference signal from the ground target. They actually could be repointed to various receivers. The ground stations would be relatively cheap so it wouldn't be all that important to maximize their utilization. (Source: The Case for Space Solar Power)
- spacemark 3y agoNo night? Where are you putting these satellites? The only orbit that doesn't eclipse is sun synchronous, an already crowded orbit. Even GEO satellites experience eclipse.
- etskinner 3y agoThey address this in the article: Only twice per year are the panels in shadow, at the equinoxes. Presumably all the rest of the time they're slightly above/below the earth with respect to its orbit. It's the same reason the moon is lit nearly all the time.
- mecko23 3y agoRespectfully, I believe you are inaccurate on both accounts, sun synchronous orbits (SSO) only have no eclipse if their orbital plane is within a very degrees of the terminator, this of course widens with altitude but there exists far more possible SSOs with eclipses than without. Secondly with GEOs as with any very high altitude orbit the eclipse time trends towards zero so effectively at a GEO the eclipse time is minimal compared to the illuminated time. Of note the length for the eclipse time of GEO varies throughout the year.
- spacemark 3y agoRespectfully, you are not correct that eclipse in Geo is insignificant. It drives many engineering constraints for spacecraft systems. Look I get why people are excited about space space solar power, but I've been in this industry for 15 years and when you dig into the numbers and understand the realities of spacecraft engineering, SBSP just seems like a fool's errand. It may not always be that way, but the technical challenges are extreme and costs are still nowhere near what would be required to make it work. You can chalk my comments up to a grumpy engineer tired of the cyclical SBSP pushes that never go anywhere.
- sidewndr46 3y agoYou do realize the Earth doesn't have "night" as a globe-wide event right? If it's night here, it must not be night somewhere else.
- DennisP 3y agoYeah everybody knows that. But transmission by wire halfway around the globe would be pretty expensive, and carry geopolitical risks.
- pengaru 3y ago> and carry geopolitical risks. And a solar death ray aimed at the planet doesn't?
- DennisP 3y agoAs I noted in another comment, it's not a death ray. Even with a reference signal from the ground, it's not concentrated enough to cause harm. Regardless, I don't think long-distance transmission is a viable solution to solar intermittency.
- LargoLasskhyfv 3y agoBut it could be? Becaus phased array? See also https://en.wikipedia.org/wiki/The_Noah%27s_Ark_Principle https://en.wikipedia.org/wiki/The_Noah%27s_Ark_Principle
- ben_w 3y agoNot for a single device with a fixed wavelength and size; unless someone figures out a way to cheat quantum mechanics and the diffraction limit, how well you can aim light is directly related to the size of your aperture (/antenna) in wavelengths. Convincing governments you've not cheated with a gigawatt optical laser on your satellites (optical wavelengths being smaller than microwaves makes them easier to focus with smaller parts), that's a separate question. I assume an Iranian one of these would get destroyed by Israel for the same reason they attack their neighbour's nuclear reactors.
- oceanplexian 3y ago> They could potentially be extremely light for the area (micrometers to tens of micrometers thick at most needed for light absorption). This is really the key, if you can make a solar panel that’s as light and thin as say mylar, and then unfold it when you get to space, we could put up several kilometers of solar panels without requiring much mass at all. It’s not like there’s wind or rain up there to wear it down.
- regularfry 3y agoYou might not be able to do a mylar-thick solar cell, but you can certainly make a mylar-thick reflector for a concentrator. Out of mylar.