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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

#21

Post by Sagat »

kokotko wrote: post #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…

I know Musk is worshipped by the Hacker News crowd (and rightly so) but as with all things related to technology it's really hard to make predictions considering the fact that there could be a "black swan" type breakthrough or accidental discovery that completely changes everything.

Re: Harvesting solar power in space and sending it back to Earth

#23

Post by InclinedPlane »

kokotko wrote: post #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…

He's not exactly wrong but "it's ridiculous" is never a good gauge of what's feasible. Most of what we use on a daily basis is pretty ridiculous if looked at from the right perspective.

And while I don't have time right now for a complete rebuttal to Musk's criticisms I will point out that he's being somewhat of a hypocrite here. He's complaining about photon to electron to photon to electron conversion, but consider what might be his ideal: ground based solar power and electric cars. The only reasonable way to make that work is through photon to electron to battery to electron to battery to electron systems, which are every bit as ridiculous and ineffecient as what he is complaining about.

Re: Harvesting solar power in space and sending it back to Earth

#24

Post by steelaz »

kokotko wrote: post #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…

What about countries that get very little sunshine through winter season, scandinavian countries for example?

Re: Harvesting solar power in space and sending it back to Earth

#25

Post by jtfairbank »

Sagat wrote: post #21
kokotko wrote: post #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…

I know Musk is worshipped by the Hacker News crowd (and rightly so) but as with all things related to technology it's really hard to make predictions considering the fact that there could be a "black swan" type breakthrough or accidental discovery that completely changes everything.

He didn't predict anything- he analyzed the existing technology and infrastructure to conclude that the cost-to-benefit ration was too high. His argument stands until a 'black swan' type breakthrough occurs, and by its very nature there is no guarantee that will happen.

Re: Harvesting solar power in space and sending it back to Earth

#26

Post by payload »

InclinedPlane wrote: post #23
kokotko wrote: post #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…

He's not exactly wrong but "it's ridiculous" is never a good gauge of what's feasible. Most of what we use on a daily basis is pretty ridiculous if looked at from the right perspective. And while I don't have time right now for a complete rebuttal to Musk's criticisms I will point out that he's being somewhat of a hypocrite here. He's complaining about photon to electron to photon to electron conversion, but consider…

Except then you consider the alternatives :-/

photon to electron in space to photon' to electron on ground ≃ photon to electron on ground

photon to electron (on ground) to battery (filling station) to electron to battery (car) to electron to kinematics VS raw oil (limited on this very planet) to petrol to kinematics

Also not considering resistance loss and petrol transportation. A little bit more complicated :)

Re: Harvesting solar power in space and sending it back to Earth

#27

Post by lucian1900 »

omh wrote: post #15
kokotko wrote: post #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…

This seems to assume that you have the ground area on Earth for the panels. That's true where Musk is working in the US, but not for many smaller countries. Of course I guess it that for those countries it would still be easier to put the panels somewhere else and build out the connection infrastructure than to put it in space.

Surface area is at an even higher premium in space. One house > one satellite.

Re: Harvesting solar power in space and sending it back to Earth

#28

Post by jacques_chester »

vacri wrote: post #8
jacques_chester wrote: post #2

Before 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.

Digging into it some more, it looks like I was wrong.

The studies use 2.45Ghz, which is also used in most microwave ovens.

The actual offsetting design element is that energy is received over a large area -- 10km^2 -- so that at any one point the radiation that a human or other living creature would receive would be below the safe threshold.

Goddamit I hate being so confidently wrong.

Re: Harvesting solar power in space and sending it back to Earth

#29

Post by jacques_chester »

abecedarius wrote: post #3
jacques_chester wrote: post #2

Before 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…

I reckon I might have read that book too. Certainly the art rings some bells.

Re: Harvesting solar power in space and sending it back to Earth

#30

Post by jacques_chester »

kokotko wrote: post #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…

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 real competitor -- is plain old fission.

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