Power and the Future
2007-05-12
The world has never been a perfect place, and now is no exception. One recent problem that I hear a lot about is the high cost of gasoline, which seems to have gone up because of Hurricane Katrina and never quite managed to work its way back down to the levels “ought” to be at. This, along with certain other factors, has led to increased interest in fuel efficient cars, hybrids, hydrogen fuel cells, and the like. The fact that fossil fuels will run out in the foreseeable future is also becoming more prevalent, although that might be a coincidence. The solutions that people come up with can be divided into two rough categories: short term and long term. The short-term solutions, like hybrid vehicles, tend to be cheaper and involve less change, but they only delay the problem to a future date. The long-term solutions, on the other hand, attempt to solve the problem forever. Generally, neither category is sufficient in itself.
One problem that arises, however, is that the solutions tend to be energy-intensive. The production of hydrogen from water, for example, must, according to the Second Law of Thermodynamics, require more energy than the hydrogen releases when burned. This, unfortunately, leads to a new problem. A lot of old power plants are nearing the end of their useable lifetime and need to be replaced, but we are not exactly sure what with. People are often against the basic design, where fossil fuels are burned to produce heat. Not only are the fuels in short supply, this also contributes to the greenhouse effect. Fission, although often held up as environmentally friendly, leaves radioactive waste that has to be stored in shielded containers for actual billions of years. Solar power only works when the sun is shining, hydroelectric dams result in massive flooding and ecological damage, and fusion power, despite being just about ready for at least 20 years, still doesn’t work. There are a few other ideas, such as windmills or tidal, but they have limited power output.
One all-but forgotten possibility is the solar power satellite. The basic idea is to load a satellite with solar panels, send it into orbit, and beam the energy back to earth as photons, where they can be used like really intense sunlight that still shines at night (except for a few days near the equinoxes). The main advantage of this is that there is no night in space; meaning that the only time you can’t collect sunlight is when there is something in the way, which, if your satellite is in a geostationary orbit, will only happen for a few hours a night near the equinoxes or if the moon gets in the way. There is also a lot more energy in space than on the ground, because most of it is blocked by Earth’s atmosphere, such as the infamous UV rays. As well, an orbiting power plant would be much less vulnerable than one on Earth, not only to normal wear and natural disasters, but also to hostile action. It takes almost as sophisticated technology to destroy satellites as to launch them.
Twenty-five years ago, 5 GW solar power satellites were estimated at a cost of $11 billion each, with and upfront cost of about $90 billion for research and development and a fleet of Heavy Launch Vehicles, which would be a lot like a bigger version of the shuttle. Inflation, bureaucracy, and increased safety standards have probably pushed the price up to 3 or 4 times that by now. The price isn’t as outrageous as it seems, however, as an oil-burning power plant producing an equivalent amount of power would requires 200,000 barrels of oil a day, currently at about $60 per barrel, plus incidental costs. Finally, we know the solar power satellites will work and don’t take fossil fuels, and even if the price is uneconomical, they will generate electricity. That’s got to be worth something.
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