NASA Spaces on Energy Solution

Wired News ^ | Tuesday, June 22, 2004 | John Gartner

[Momaw Nadon]

Scientists from around the world will soon gather to discuss how satellites could be used to address the world's energy needs by relaying solar power to Earth. But the U.S. government's decision to abandon research in 2001 could prevent the alternative energy source from ever seeing the light of day.

[Momaw Nadon]

FYI and discussion

[bitt]

would rather these brainiacs put their minds to creating the energy-machine on the back of the DeLoria in "Back to the Future"...didn't look too involved - looked like a Mr. Coffee machine.... :)

[RobRoy]

I saw Diamonds Are Forever. I don't want one of THOSE up there.

[RandallFlagg]

I'll say it again..

Build surf-generators on rocky beaches and power hydrogen collectors for autos.

Go nuclear for land-based energy.

Mine the sea beds for additional resources.

Give the environazis the bird.

[r9etb]

The Wired spin on it sounds like the old "100 mpg carburetor" conspiracy theorists. NASA actually did a reasonable assessment, and rejected the concept.

There are two underlying issues at work here.

First, there's the problem of paying for building and getting the power generation stuff on-orbit. That's a lot of cash.

The second problem is getting the power back down to the ground. Aside from the cost of that, there's also the difficulties of classic NIMBY/Enviro lawsuits, and such, coming from the transmission of microwaves over a large area.

There's also the issue of how you deal with eclipse season -- something all GEO satellites have to deal with. Where does the energy come from when your satellite is in the dark?

I don't think there are any technical show-stoppers (except maybe the high-power microwave transmitters) -- the real problem is high costs, from a variety of sources.

[Brett66]

I think SPS will be a niche market that will be utilized for remote areas on Earth that are difficult to supply with power. I think once we have a robust space infrastructure that demands in-space power, it will be the choice for in-space applications. Considering that it would have to compete with cheap energy sources such as coal to be competitive on Earth, I don't see it being in widespread use down here, but I see it as a good solution for space-to-space power applications.

[r9etb]

Oh, and one other thing: maintaining the solar arrays would be a bitch. You'd have to launch a robotic or manned mission to replace/upgrade degraded panels (more expense). You'd probably also have to do a lot of upkeep on the satellite bus/transmitters. You probably couldn't afford to replace too many replacement satellites.

Note also the difficulty of trying to spread the task over several satellites -- they'd have to be pretty close together at GEO, in the already popular "over the U.S" slots, and you'd have some fun multi-vehicle relative motion issues as well.

[Gorjus]

Brandhorst said satellites in geosynchronous orbits -- and always in sunlight -- could continuously collect solar radiation and safely beam the energy to Earth as microwaves..

First, if it's in geosynchronous orbit, it's not always in sunlight. The Earth's shadow reaches all the way out to the moon.

Second, people get upset about being near power transmission lines now, and enough energy density from space to matter will be roasting flying birds (and people under the beam) with a whole lot more energy than people fret about now.

There are two aspects to the problem. One is basic science such as more efficient solar cells. There are programs for that now (including those funded by NASA) even if they're not formally pointed at Solar Power Satellites. The second is the cost-effective production of usable power. That's an engineering problem, not a basic science problem. And if it's cost-effective, then there are plenty of commercial companies who would be happy to produce the satellites.

We don't need government involvement in this as a way to solve the world's energy needs. Just the opposite. Keep the government out of it and it will happen faster (except for the fact that government agencies can get 'sweetheart deals' around regulations that limit private companies, but the solution to that is obvious).

These guys are just upset because their meal ticket got yanked. They want grants for research. The grandiose justifications are just a way to open up the money spigot for their personal use.

[RightWhale]

Interest in this peaked about the time of the Arab oil embargo and when the Dept of Energy was created. The Dept of Energy never did anything about it. It's probably too late now to help avoid the Peak Oil crisis. 30 years ago it was possible, now it's not. Thanks are due to the people in DC with all that great vision and leadership skills.

[r9etb]

I think SPS will be a niche market that will be utilized for remote areas on Earth that are difficult to supply with power.

That's probably a very difficult technical challenge. You want your ground reception antennae to be over a pretty wide (square miles at least) area -- which raises questions of whether it might not be easier to run power lines, than to build the microwave collector.....

Otherwise, you need to have a very concentrated microwave transmitter, and extremely tight satellite/transmitter pointing, to serve a small, and necessarily very high-power ground antenna. (The last thing you want is for a powerful microwave beam to wander away from the antenna to some inhabited village.)

[GOPJ]

Or Zero Point...

[r9etb]

We don't need government involvement in this as a way to solve the world's energy needs.

Actually, you do. There's lots of folks who may object to Private Company X irradiating them with microwaves.... The usual approach is to cover, say, the Arizona desert with antennae -- but who's gonna pay for that?

[RightWhale]

government agencies can get 'sweetheart deals'

That should be illegal. Sounds like direct competition with the private sector.

[GOPJ]

BINGO:

We don't need government involvement in this as a way to solve the world's energy needs. Just the opposite. Keep the government out of it and it will happen faster (except for the fact that government agencies can get 'sweetheart deals' around regulations that limit private companies, but the solution to that is obvious).

[RobRoy]

You nailed it. I was looking for ANYTHING in the article mentioning those risks and came up emptyhanded - which means the article is a "hit piece." This particular solar power sounds simple, but as you pointed out, the devil is in the details. And it could be a VERY powerful weapon with minor modifications.

[Gorjus]

but who's gonna pay for that?

You and me. It doesn't matter if we pay the government taxes, or we pay a commercial provider for power. The consumer still pays all bills.

Just where do you think government funding comes from, anyway?

[Gorjus]

And it could be a VERY powerful weapon with minor modifications.

Actually, I don't think so. I think they'd never let the power density get high enough to be a real risk. And it may not be practical anyway. Getting a big enough aperture to keep a high-power beam on target - continuously - from 22,300 miles away would be a real problem. And a laser isn't any easier to point as it heats up the air it passes through. So we'll probably be stuck with fairly low power density where it doesn't hurt if the beam wanders a bit.

But that might never be cost-effective relative to putting the solar cells on earth. If the cells are 25% efficient (a worthy goal), and transforming it to a beam is 50% efficient (and what do you do with the waste heat), with another 25% efficiency on the receiver end, you're probably better off to keep the solar cells on the ground and take the day-night cycle. Especially since solar cells in space have a half life of about a year (and replacing them in geosynchronous orbit will be a bit..., ahem, a problem).

[bitt]

'Or Zero Point...'


thank GOD for google...for any other nitwit,

http://www.americanantigravity.com/nick-cook.html

I STILL like the BTTF Mr. Energy machine...

[RightWhale]

How does zero point energy work? Can I buy a generator for the house or car?

[Dreddnafious]

i think more interesting is the moon option. putting the collector arrays on the surface of the moon. not only does it fix some of the stability issues, but you kill two birds with one stone, providing on-site power to any future moon colony and at the same time increasing the mandate for one.