Harvesting solar power in space and sending it back to Earth
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Re: Harvesting solar power in space and sending it back to Earth
#2Before the SimCity joke parade begins, remember that the frequencies that are useful are the same frequencies that won't interact with biological matter.
Why?
Because if you pick a frequency that, like a microwave oven, heats up water, then you are wasting energy. The atmosphere is well stocked with water at varying, often unpredictable levels. Wasting beam energy on heating up passing water molecules is kinda pointless, so the frequencies chosen pass through without interacting.
So no. A beam going off axis will not set your city on fire.
In terms of the actual concept, the original book to read is Gerard O'Neill's 1976 The High Frontier. O'Neill proposed to boostrap orbital colonies at L4 and L5. These colonies would build and maintain orbital solar stations.
I think that realistically, that window has passed. If solar power stations were built now, it'd all be done remotely. That's a pity, because as romantic engineering visions go, O'Neill colonies were amazing: http://en.wikipedia.org/wiki/File:Spacecolony4.jpeg
Re: Harvesting solar power in space and sending it back to Earth
#3Before the SimCity joke parade begins, remember that the frequencies that are useful are the same frequencies that won't interact with biological matter. Why? Because if you pick a frequency that, like a microwave oven, heats up water, then you are wasting energy. The atmosphere is well stocked with water at varying, often unpredictable levels. Wasting beam energy on heating up passing water molecules is kinda pointl…
Powersats as basis for space colonies never added up for me -- couldn't the funders find work crews willing to live closer to spam-in-a-can style for higher wages, with overall much lower cost?
But I loved the space colony vision even so, and it was sad feeling it slip away over the decades. You can read Heppenheimer's book online: http://www.nss.org/settlement/ColoniesInSpace/ (I remember it as better than O'Neill's, though of course O'Neill gets much more credit for the ideas.)
Re: Harvesting solar power in space and sending it back to Earth
#4I'm confused. Is there an announcement or update of some sort associated with this project? It's unclear from the article.
Re: Harvesting solar power in space and sending it back to Earth
#5[deleted]
Re: Harvesting solar power in space and sending it back to Earth
#6This might make sense _if_ we had run out of real estate to plop down solar panels, but that's not the case. You can easily cover a few acres in static mounted solar panels, hose the dust off them every now and then, and they'll last 30+ years. A space based power plant, that crap will break down in a few years max.
Re: Harvesting solar power in space and sending it back to Earth
#7"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 panel is on-orbit, you get twice the solar energy - assuming that it is out of Earth's shadow - but you've gotta do a double conversion. You've gotta convert it from photon to electron to photon, back to electron. You've got to make this double conversion, so, okay, what's your conversion efficiency? Hmm. All in, you're going to have a real hard time even getting to 50%. [The solar cells are better.] It does not matter, put that cell on Earth then. See, that's the point I'm making. Take any given solar cell, is it better to have it on Earth, or is it better to have it on orbit? What do you get from being in orbit? You get twice as much sun - best case - but you've got to do a conversion. You've got to convert it the energy to photons - well, you have incoming photons that go to electrons, but you - you've gotta do two conversions that you don't have to do on Earth, which is you've got to turn those electrons into photons and turn those photons back into electrons on the ground, and that double conversion is going to get you back to where you started, basically. So why are you bothering sending them to bloody space. "I wish I could just stab that bloody thing through the heart." BTW - electron to photon converters are not free and nor is sending stuff to space. Then it obviously super doesn't work. Case closed. You'd think. You'd think case closed, but no. I guarantee it's gunna come up another ten times. I mean, for the love of God."
Elon Musk (http://shitelonsays.com/transcript/elon-musk-panel-bta-2012-...)
Re: Harvesting solar power in space and sending it back to Earth
#8Before the SimCity joke parade begins, remember that the frequencies that are useful are the same frequencies that won't interact with biological matter. Why? Because if you pick a frequency that, like a microwave oven, heats up water, then you are wasting energy. The atmosphere is well stocked with water at varying, often unpredictable levels. Wasting beam energy on heating up passing water molecules is kinda pointl…
http://en.wikipedia.org/wiki/Water_window
It doesn't have to be absorbable by water to interact with biological matter.
Re: Harvesting solar power in space and sending it back to Earth
#9"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…
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.
Re: Harvesting solar power in space and sending it back to Earth
#10"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…
Seems to me that a significant advantage of 'space solar' is that you can ditch a significant amount of ground based distribution infrastructure. Transformers are pretty efficient but lose about 2% per step up/down[1], power lines are another 1-4%/100 miles[2], then you have losses related to storage since you can't turn solar on/off at will like you can with hydro or fired plants.
If a single solar sattelite [multiple for redundancy, in reality] can replace a large proportion continent's energy infrastructure, it starts to sound a lot more attractive.
1. http://en.wikipedia.org/wiki/Transformer#Energy_losses
2. http://en.wikipedia.org/wiki/Electric_power_transmission#Los...