Comments on: DoD Eyes Space-Based Energy Source

By: stephen russell

stephen russell — Sat, 29 Dec 2007 04:13:05 +0000

Finally Gearld K O Niells dream for Space based Solar Power takes root since book debut in 1975.
Major Income source.
Rectenna sites can be: No Africa, Norway, Russia, China, Greenland, Australia, CO, KS, WY,
Phillpines, Dubai UAE, Java, Brazil.
Amen.

By: Praedor Atrebates

Praedor Atrebates — Fri, 28 Dec 2007 19:20:06 +0000

I remember reading about this sort of thing back in the 80s in Gerard K. O’Neill’s books about ways to build huge, self-sustaining space habitats. Quick synopsis: mine most materials from the moon, build HUGE spinning space habitats capable of holding up to 10,000 people per habitat. Interior is spacious and open, with hills, water, trees, grass, birds, insects, etc. Part of paying for all this was the mining operations on the moon used to build them in the first place AND solar power stations in orbit. Huge arrays placed so that there are stations in needed areas that are always in sunlight. The energy from these huge photovoltaic arrays is converted to microwaves and beamed down to the Earth’s surface. On the ground is a huge microwave antenna farm. Open, airy…basically metal screens suspended over the ground (sunlight, rain, etc, can still get through).
The idea was that these would be relatively benign and clean. Except for the local energy density of microwaves, of course, and the recent indications that even the microwave energy emitted by cell phones is enough to increase the rate of brain cancer in heavy cell phone using people (annoying jerks that they are).
I suppose a more modern variation on the theme might be to “fly” the receiving antennas high in the atmosphere (stratosphere) on tethered aircraft/kites. They absorb and convert the microwaves back to electricity and transmit the juice down their tethers. Overall, you would likely be better off with merely changing building codes to REQUIRE a minimum amount of solar energy collector on all new houses and BIG incentives to get them on older housing within the geographic areas where this makes sense. Both for hot water generation AND for electricity generation. Throw in wind farms, geothermal, tidal and current generators on the coasts, some modern nuke plants, and when absolutely necessary and unavoidable, coal powerplants with carbon sequestration (and ban ALL incandescent light bulbs in favor of CF or LED lighting) and you do a LOT to fix all that ails us.

By: Nuke-E

Nuke-E — Fri, 28 Dec 2007 18:57:47 +0000

Eric -- Making more fuel than you consume is the principle behind fast breeder reactors. It's a fundamentally different technology from the Light Water Reactors we use in the US. Basically, "waste" neutrons from the Uranium 235 fission reaction are captured by Uranium 238 (not fuel, won't fission) and convert it to Plutonium 239 (fuel). So it's not creating energy, it's converting a non-fuel substance into a fuel. Sort of like converting seawater to hydrogen. France experimented with fast breeder reactors on a commercial scale (the Phenix and Super Phenix reactors), but they gave up breeding because fuel reprocessing is such a hideously dirty process. In the US, President Clinton cut funding for breeder reactor research in 1993, and it has never been explored on a large scale. Considering the environmental impact of military fuel reprocessing in Hanford, WA, magnifying that 1000 times over for commercial reprocessing is a step we're not technologically ready to take. Ken, you're confusing the cost of power with the cost of generating capacity. The cost of a 1,000 megawatt nuclear plant today (if anyone were ordering them) would be about $2.5 billion, with about a 40 year plant life and actually generating power about 75% of that time. Allan Swank, there's no such things as "unnecessarily pushing the bounds of technology". If people didn't push the bounds, we wouldn't have the semiconductor, the transistor, the light bulb, the bow and arrow. Really, what technological achievements do you consider "necessary"?

By: Eric

Eric — Fri, 28 Dec 2007 15:30:49 +0000

I’m interested to hear how something can produce more fuel than it uses, since this sound like a violation of conservation of energy. This probably means I didn’t understand what was meant by the statement.
Anyway, we should separate ideas about energy sources from ideas about energy carriers. Energy sources are places we get energy from initially — the sun, fossil fuels, coal, geothermal sources, wind, tides, waves, the motion of rivers. energy carriers are ways to carry that energy to where it is needed — wires, batteries, ethanol, hydrogen. Even in a country powered entirely by nukes there will be a role for energy carriers, probably hydrogen, because you can’t put a nuke plant in your car. The energy loss to transfer the energy in nuclear fuel to a chemical is worth it economically if that chemical can be placed in a vehicle, be it car, boat, or airplane, and used to power the motion of that vehicle.
This is a long way of saying that hydrogen is not a suitable replacement for either nukes or solar sats. Either, however, could provide the power to electrolyze seawater to make hydrogen to power vehicles. (Or you could tinker with some deep-sea bacteria that seem to want to burp hydrogen while they feed, and put them in a tank out back with some bacteria-chow.)

By: pedestrian

pedestrian — Fri, 28 Dec 2007 14:27:00 +0000

>beaming energy down from satellites — will provide “affordable, clean, safe, reliable,
>sustainable and expandable energy for mankind.“
Cost performance is the priority. Forget the rest. If it isn’t economic, it’s likely not going to make through.

By: Ian

Ian — Fri, 28 Dec 2007 06:45:18 +0000

beaming energy down from satellites — will provide “affordable, clean, safe, reliable, sustainable and expandable energy for mankind.“
Not to mention the technology has a dual use for space based energy weapons.
NOD is attacking! Charge the ion cannon!

By: exnuke

exnuke — Thu, 27 Dec 2007 22:25:30 +0000

Sorry guys. This idea has been around since the ‘60s. The major problem with it is the power density of the transfer beam. To much energy and you fry whatever happens under the beam. This means that the antenna will be huge. Nice idea, it should even work. Just don’t let the enviromentalists know what you are up to. They’ll shut it down just as the shut down the only power source we have that will produce more fuel than it burns. What? You didn’t know that such a thing existed? Well, sweet-cheeks, there just happens to be such a technology. It just happens that Nuclear Power can create more fuel than it burns allowing the country to be independent of fossil fuels. To bad it will never happen as long as we listen to those who would destroy us and our civilization.

By: Steve Brent

Steve Brent — Thu, 27 Dec 2007 17:55:00 +0000

What would this energy do to the atmosphere, the ozone layer.?

By: Steve Brent

Steve Brent — Thu, 27 Dec 2007 17:54:24 +0000

What would this energy do to the atmosphere, the ozone layer.?

By: A.Hoffmann

A.Hoffmann — Thu, 27 Dec 2007 11:41:57 +0000

Looking at alternative forms of enery production is a great idea. I do not feel we need to go to such extremes. Keep it simple, to create energy a force is required. This force is utilized by converting its enery into something we can use. I believe with the poles of the earth could provide unlimited energy. By building a conduit from one pole to the other we could create a difference in potencial due to magnetic differencial. Let the world create the power for you. This would require International cooperation which is the biggest obstical.