Solar power in space?

April 16, 2009 1:35 PM

Would orbiting solar power farms be remotely practical?

So I've just read this story and it fairly blew my mind; now that's a 21st century solution to the energy crisis. Made me think though. Is this evenly remotely practical? It all seems to make a lot of sense, apart from the disgustingly high cost of putting stuff into orbit.

The most curious part of it for me though was the means of transmitting electricity via radio waves at 90% efficiency. I totally didn't realise this was possible. According to the Guardian article, this is more efficient than using wires to transmit power, wow. If this is true. why don't we have a network of satellites transmitting power around the world? Set up the mother of all solar plants in the Sahara and broadcast the power across the globe.

So really I'm asking about what some of you engineer types think about the story. Does this seem like a genuinely innovative idea, a flashy distraction or a vapourware nonsense proposal?

Thanks,

posted by greytape to science & nature (10 comments total)

There is a pretty good wikipedia article on this.
posted by gregr at 1:46 PM on April 16

From a political perspective, I think a large part of non-adoption is that this infrastructure is, with a few software changes, equivalent to having an orbital platform equipped with death-dealing masers. The kind of juice you could muster would make the popcorn scene from Real Genius look like frying an ant with a plastic magnifying glass on an overcast day.
posted by adipocere at 1:50 PM on April 16

The cost of lifting all the material into orbit is the prohibiting factor.

If a nation or private party was able to erect a space elevator, they could gain a monopoly on both space-based solar electricity, and cheap access to orbit.
posted by General Tonic at 1:57 PM on April 16

Two problems with what you outline.

First, you can generate solar power right here, right now on earth. It may be 100 times better to be in space, but it's 101 times cheaper to do it here on earth. Any benefit you'd gain by being in space would likely be outweighed enormously by spending your resources to improve land-based efficiency.

Second problem:
Set up the mother of all solar plants in the Sahara and broadcast the power across the globe.

Transporting electricity across long distances has its own set of problems.
posted by Cool Papa Bell at 1:58 PM on April 16

There's supposedly a project which will be functional by 2016,

California's biggest energy utility announced a deal Monday to purchase 200 megawatts of electricity from a startup company that plans to beam the power down to Earth from outer space, beginning in 2016.
posted by nomisxid at 2:19 PM on April 16

Although it's 10+ year old information at this point, there are a few interesting archived newsgroup postings on the subject of solar power satellites at the excellent yarchive.net site.
posted by FishBike at 3:39 PM on April 16

...why don't we have a network of satellites transmitting power around the world?

Although they would, in theory and probably in practice, be an efficient way to transmit power around the world, the cost to deploy such a system would be prohibitive. So would the cost to deploy solar collectors in orbit.

On the other hand, we sent humans to the moon and back, at considerable cost and effort, so we could do this too — if we really wanted to.
posted by exphysicist345 at 8:00 PM on April 16

Previously.
posted by Wet Spot at 8:08 PM on April 16

Anybody who still thinks that large, centralized power generation of any kind is a good idea needs to read Soft Energy Paths and then pay attention to the way power generation methods have actually been heading since its publication in 1977.
posted by flabdablet at 9:42 PM on April 16

California's biggest energy utility announced a deal Monday to purchase 200 megawatts of electricity from a startup company that plans to beam the power down to Earth from outer space, beginning in 2016.

Uh-huh. PG&E gets a large short-term PR boost, and the startup company gets something to wave in front of potential investors. Seven years from now, the startup will likely have either disappeared the way startups do, or will be stringing along investors the way Moller does.

It may not result in generating any money, but some people will get a lot of money from this.
posted by happyroach at 5:46 PM on April 20