How to achieve energy independence  (Space)

Whenever the subject of excessive dependence on oil imports comes up, someone always calls for achieving energy independence, but then the discussion gets diverted into such remedies as energy conservation, wind farms, geothermal and ocean thermal sources, ground-based photovoltaic arrays, biofuels, coal, ocean deposits of methyl hydrate, and, of course, the big ones -- nuclear or fusion reactors.

However, there are problems will all of those. No reasonable amount of conservation is going to keep our economy going if energy supplies are cut off. Wind farms, and geothermal and ocean thermal sources, can help in some places, but one can't depend on them as a replacement for fossil fuels. Ground-based photovoltaic systems are still somewhat expensive, although the cost is coming down. Biofuels turn out to cost more energy and other resources than they save, at least if corn is used instead of sugar cane or switchgrass. Coal and methyl hydrate will just accelerate the global warming problem. Nuclear presents the problems of waste disposal and proliferation, and fusion reactors don't work yet.

The one alternative that is seldom mentioned is space solar power: putting photovoltaic arrays in orbit and beaming the power to receiving antennas on the Earth. It is not a new idea. It is estimated that about 40 satellites in geosynchronous orbit could meet the needs for energy of the entire world, and it it was the United States who puts them up and operates them, we would be the energy exporters to the world instead of importers. Once in operation, it is estimated the cost of energy from them would be less than half the cost from other sources, and that it could pay off the investment to put up the system in less than a decade. It requires little new technology, other than ways to bring down the costs for vary large systems. It has much support from leading engineers and scientists, including a team within NASA. And nations like Japan are moving ahead to do it without waiting for us.

So why aren't we doing it? The answer, as usual, is politics. The alternative is opposed by the proponents of nuclear power, who keep making the argument that Earth-to-orbit lift costs are too high, when the proposal has long been to use materials mined from the Moon or an asteroid rather than lifted from Earth. The real problem for them is that such a proposal doesn't make them a lot of money. It would be creating an industrial system in space that they would not control and from which they could not profit.

The idea of collecting solar energy in outer space and beaming it to earth is one that is well developed conceptually, and research on its feasibility has been funded by Congress.

"Ottinger and Nader are against it, so the idea can't be all bad," writes a reader. But it's not that simple. Both of these energy scholars are so unreliable that one cannot even rely on them always being wrong. They don't like two things about the solar satellite:

Unlike rooftop cells producing piddling amounts of energy at exorbitant costs, it would give thousands of megawatts indiscriminately to everybody (not just sensitive, aware and affluent suburbanites); and it would require advanced technology managed by a corporation of shareholders instead of spending taxpayers' money on wheelbarrows and treadmills.

On the other hand, many of the SPS's vehement promoters want to go into space for everything and at all costs, including the taxpayers' costs.

So let's judge the idea on its merits rather than on the company it keeps.

Unlike energy in space, which can be beamed to other space vehicles by laser beams (requiring only small reflectors), energy from space must transverse the atmosphere, which leaves only microwaves as the carrier: Laser light would not penetrate the cloud cover, and longer radio waves would require unreasonably large antennas, for any antenna (or reflector) must have a diameter several orders larger than the wavelength of the transmitted radiation if it is to concentrate it into a narrow beam.

The Luddites who found it possible to brainwash people into fearing nuclear power on objectively indefensible grounds would find it even easier to scare them with the dangers of an aircraft flying into the beam, or the beam moving off target (the receiving antenna on the ground) due to a malfunction of the transmitter antenna on the satellite. That beam would transmit a power of several thousand megawatts ¾ and The Zapping of America screamed murder about this type of radiation at the microwatt level.

But far more important than this incidental aspect are the technical and economic considerations. The technical advantage over solar-electric plants on earth lies ultimately only in the constant (and just slightly higher) illumination of the collectors ¾ no night or cloud cover. But that is an advantage over a system that is not very good in the first place. The dilute flow of solar energy remains; in particular, the area for the collectors, though not owned by anybody, is very much harder to come by.

As for economics, we are talking about tens or hundreds of square miles of collectors, to be put up at a cost of tens (hundreds?) of billions of dollars over many years, to produce the power that could be produced by tens of nuclear or coal-fired units on earth.

The cost of an installed kilowatt, claim the supporters, is close to "competitive" with nuclear or coal, and will look better as the cost of oil goes up. No, object the opponents, it comes to two or three times the cost of a conventional kilowatt. But without calling either side a liar, take a look at the oft repeated story of oil shale, synthetic fuels, and other energy sources. OPEC oil prices were to catch up with the high cost of these sources in a year or two. And by Jove, in a year or two they did catch up ¾ with the cost of a year or two ago...

So all things considered, we believe there are a million good reasons to go forward into space; but a vulnerable, overpriced energy source is not one of them.

Space solar power gets a boost

After spending weeks in information-gathering mode, a Pentagon analyst says the idea of putting satellites in orbit to harvest solar power and beam it down to Earth has lots of merit - and a test of the concept could be set in motion by 2015.

First word of the thumbs-up came from Col. M.V. “Coyote” Smith, who is heading up the National Security Space Office's study on feasibility of space-based solar power, via a presentation in the Second Life virtual world. Smith's comments were passed along on the Web by the Frontier Spaceport blog - and are due to be repeated today at a U.S. Air Force Academy conference on space solar power.

Frontier Spaceport's Robin Snelson quotes Smith as saying he'll extend his study and deliver an interim report on Oct. 11. Based on the posting, it sounds like Smith is sold on the idea:

"He spoke eloquently of the need for fleets of spaceplanes and reusable rockets to accomplish the baseline goals of the study, which envisions 40 powersats in geosynchronous orbit producing 10 percent of U.S. energy needs by the year 2050. (Hey, isn’t that the year Gerard O’Neill predicted way back in the 1970s? it sounded so far away then…)

"A first demonstrator project in, say, the year 2015 might power a military base, be capable of sending power to disaster areas, or transmit energy to troops abroad. The cost of petroleum fuel, not only money but lives lost in wars fought over oil, is a big driver of the Pentagon’s interest in space solar power. Coyote has gone from skeptic to enthusiast since the study began. ..."

That's music to the ears of space solar power fans, but will the idea really fly? There are several futuristic energy strategies out there, ranging from fusion power fueled by lunar helium-3 to Earth-based solar power, the hydrogen economy, the bio-hol economy and beam-power nirvana. It could come down to which pie-in-the-sky strategy makes the most economic sense.

Compiled by: Yehuda Draiman