Earlier quoted context omitted.
It's like a rabbit hole, constructed out my errors.
s/out/out of/ :-)
I accidentally an everything
Harvesting solar power in space and sending it back to Earth
61–70 of 83 posts
Re: Harvesting solar power in space and sending it back to Earth
#62Earlier quoted context omitted.
What if instead of solar panels, you put up big mirrors, and instead of earth you have them orbit far closer to the sun? Btw, great quote.
yes, and shuttling antimatter batteries back to earth.
Heh, that sounds great.
Someone make a stupid mistake on the ground, and your ship crash, and then BOOOM, a 20km wide hole shows up in your space center.
Re: Harvesting solar power in space and sending it back to Earth
#63They can just fill Energons and send those back to earth... http://tfwiki.net/wiki/Energon
Re: Harvesting solar power in space and sending it back to Earth
#64why convert from photon to electron back to photon? Why not just use mirrors to focus light on lasing material and create a laser directed to a solar panel/s on the Earth and then convert to electrons?
Re: Harvesting solar power in space and sending it back to Earth
#65Earlier quoted context omitted.
The thing is that in the time when solar orbital was first discussed, solar panels sucked and oil was super-expensive. I think the O'Neill designs were based on concentrating mirrors and turbines. He claimed it could pay for itself within a standard utility company's financial planning horizon of 30 years. And then oil prices went back to normal. The real conceptual competitor at the time -- in fact, it's still the r…
But nuclear is evil and not cleantech.
Solar energy is actually nuclear energy.
Re: Harvesting solar power in space and sending it back to Earth
#66"Let me tell you one of my pet peeves: space solar power. Okay, the stupidest thing ever. If anyone should like space solar power, it should be me. I got a rocket company and a solar company. I should be really on it, ya know. But it's like, super obviously, not going to work because, ya know, if you have solar panels - first of all, it has to be better than having solar panels on Earth, so then you say, okay, solar…
Space structures can be truly enormous, hold their shape with no gravity issues, be aimed with trivial amounts of energy, have no weather issues (no cloudy/rainy days). Any number of reasons this is a win.
Mr. Musk is just ranting. He's used conversion efficiency as his whole argument. The only argument worth having is total cost of ownership, which relates to payback time.
Re: Harvesting solar power in space and sending it back to Earth
#67"Let me tell you one of my pet peeves: space solar power. Okay, the stupidest thing ever. If anyone should like space solar power, it should be me. I got a rocket company and a solar company. I should be really on it, ya know. But it's like, super obviously, not going to work because, ya know, if you have solar panels - first of all, it has to be better than having solar panels on Earth, so then you say, okay, solar…
Space structures can be truly enormous, hold their shape with no gravity issues, be aimed with trivial amounts of energy, have no weather issues (no cloudy/rainy days). Any number of reasons this is a win. Mr. Musk is just ranting. He's used conversion efficiency as his whole argument. The only argument worth having is total cost of ownership, which relates to payback time.
I imagine micrometeoroid impacts would be a significant "weather" issue.
Re: Harvesting solar power in space and sending it back to Earth
#68Earlier quoted context omitted.
Space structures can be truly enormous, hold their shape with no gravity issues, be aimed with trivial amounts of energy, have no weather issues (no cloudy/rainy days). Any number of reasons this is a win. Mr. Musk is just ranting. He's used conversion efficiency as his whole argument. The only argument worth having is total cost of ownership, which relates to payback time.
I imagine micrometeoroid impacts would be a significant "weather" issue.
Yes; of an entirely different nature than hurricanes, torrential rains etc. Unfortunately the best locations on earth for truly enormous high-efficiency solar are equatorial.
Re: Harvesting solar power in space and sending it back to Earth
#69"Let me tell you one of my pet peeves: space solar power. Okay, the stupidest thing ever. If anyone should like space solar power, it should be me. I got a rocket company and a solar company. I should be really on it, ya know. But it's like, super obviously, not going to work because, ya know, if you have solar panels - first of all, it has to be better than having solar panels on Earth, so then you say, okay, solar…
Who cares about the efficiency when solar panels weigh over 50 kg per kW? Even at SpaceX prices, the cost of launching a solar panel into space is hundreds of times the cost of the panel. If your alternatives are "buy 500 panels and put them on the ground" and "buy one panel and put it in space," why the hell is anyone even remotely considering the second option?
Wasn't the original concept for SPSS (at least in O'Neils The High Frontier) to build them out of mined asteroid materials? At that point the cost of the proposal is disconnected from the cost of launching the panels. I've heard many analyses of that which do suggest the economics of it is inevitably atrocious for ground-launched SPSS. Cost numbers for asteroid mining vary by a couple orders of magnitude though, which mitigates the above...
Re: Harvesting solar power in space and sending it back to Earth
#70Earlier quoted context omitted.
>solar panel is on-orbit, you get twice the solar energy - assuming that it is out of Earth's shadow Not quite. When compared to stationary panels (which beat trackers economically, so they should be the baseline), space-based power harvests π (yes, pi) times as much sunlight due to lack of cosine loss, plus there's the bonus of reduced reflective loss. Atmospheric and weather loss is avoided entirely. I would estima…
Concentrators have problems. If you use them with solar panels, then your panel will heat up and its efficiency will drop. Maybe lifetime as well. If you use a thermoelectric generator, you then have wearing mechanical low efficiency systems on board. In both cases you need to reject heat, which is hard in space. They also require precise pointing. There's also the problem of beaming the power to earth. If you're in…
Yep, after writing all that I realized that heat rejection is going to be a problem. Dissipating 8.4 MW is no easy feat in orbit.
At that point the balance of system probably shifts to thin film PV. There would need to be a lot of advancement in that area before such a project becomes practical.
>What about beaming between satellites? You'd need a laser for that.
I was picturing a microwave rectenna, actually.