In a bit of serendipity, several items about the future of power generation popped up on my radar recently. They nicely demonstrate alternative sources of electricity now, in the near future, and a bit down the road. Quick synopsis: the days of massive generators like the one shown to the right are numbered.
(Read the extended entry for details:)
First up is an article Alex sent my way from the Christian Science Monitor about the steadily growing popularity of solar power in suburbia.
Prodded by fears of global warming, lured by falling solar-cell prices and strong financial incentives, at least 10,000 US and 70,000 Japanese homeowners, along with tens of thousands more in Europe, installed solar energy between 2000 and 2002, say industry experts. Total global solar-generating capacity - including off-grid installations - is several gigawatts, Perez says.
But by far the fastest-growing solar group is residents who also are connected to local power grids, a segment that has gone from almost nothing in 1990 to an installed base of at least 730 megawatts in 2002 - about the size of a medium-size coal-fired power plant.
As the price for solar installations drops, and the overall efficiency of the systems increases, renewable hook-ups tied into the grid -- so that excess power is fed back into the power network, making one's electricity meter quite literally spin backwards -- are becoming increasingly popular. The variety of tax credits, incentives, and subsidies available across the United States for installing renewable home energy is staggering. In some cases, the state/federal support can cut the cost of installation in half.
Solar converts light into electricity; but how about converting heat into electrical power? Thermoelectric semiconducters take advantage of the ability of some materials to convert differentials in temperature into electricity, and vice-versa.
Mercouri Kanatzidis envisions a refrigerator that not only would keep the Maytag repairman pining by a silent phone, but could put him out of business altogether.
Gone would be the noisy compressors, the environmentally dubious coolants, and the dust bunnies under the cooling coils. Instead, says the chemistry professor at Michigan State University, the unit would rely on electricity flowing through specially designed semiconductors to keep the inside of the icebox chilled. Those same semiconductors also could be used to convert wasted heat in auto exhaust pipes, power-plant smokestacks, or other sources into valuable electricity.
This technology has been in use for decades, but the type of semiconducters used only allowed for implementation on a small scale. Kanatzidis and others have now come up with a formulation which could scale up much more readily. It's still a ways away from full implementation (and the fact that it relies on some fairly toxic metals is a problem), but the conversion of even a fraction of waste heat into electricity could be an outstanding source of power.
Finally, there's photosynthesis. The manner in which plants convert sunlight into organic energy and split water into oxygen and hydrogen has been a difficult mystery to solve. Now, a team combining efforts from the Imperial College London and the Japan Science and Technology Corp. in Yokohama believe that they've figured out a key element in the process.
Jim Barber, from the Imperial College London, sees this as someday leading to an organic method of extracting hydrogen from water for use as fuel:
"Now hydrogen also contained in water could be one of the most promising energy sources for the future. Unlike fossil fuels it's highly efficient, low-polluting, and is mobile so it can be used for power generation in remote regions where it's difficult to access electricity."
Water has always seemed a logical source for hydrogen, but the only known feasible method to separate it, electrolysis, costs 10 times as much as natural gas and is three times as expensive as gasoline, Barber said.
How soon? Who knows? It is, however, a promising development.
Regarding the extraction of hydrogen from water: would this work for salt water, or only for fresh? If the latter, it seems that -- given the impending water crises in much of the world -- that this would not be all that useful compared to other alternative energy sources. If you don't have water to drink, why worry about using it for energy?
But what about costs?
If the government has to pay for half the cost of a power installation (as for home solar) and people still aren't lapping it up, it sounds like we have a bit of a way to go on this one. I've been tracking photovoltaics prices recently; while they dropped precipitously in the early 1980's after the US spent about a billion dollars on R&D (Carter administration), there's been very little US R&D spending on PV since then, and prices have declined only moderately (few percent per year).
Existing power production capital investment in the US is on the order of a few trillion dollars. If home solar is going to make any dent in that, prices had better drop pretty significantly, or we're talking trillion-dollar levels of government investment!
Bio-solutions are fine, but they have that low-energy-density problem - are we really prepared to cover hundreds of thousands of square miles of our nation with bio-engineered energy crops? Seems a little far-fetched.
it's good idea.
my grandfather made his own "energy system" based in solar power and many things in their house used to work by that system.
unfortunately he died when i was 7 and the family didn't know how to keep the system and maybe work on it...
I think it's important to bear in mind that each of the various alternative energy proposals would be part of a larger system. Nobody is talking about trying to generate all of our electricity exclusively from (say) thousands of square miles of plants, rooftop solar, or mega wind turbines. Varied components, however, allow for varied strengths, and a more diverse -- and robust -- sustainable energy production network.
Brandon -- we still know too little about how organic water-cracking works to be able to say with certainty whether only fresh water could be used. Even if that was the case, bear in mind that hydrogen-based power generation has, as its "waste" material, pure water. Using a photosynthesis-derived method of re-cracking that water into oxygen and hydrogen would make such power systems all the more self-renewing.
Arthur -- the point of the first article linked to is that, in fact, people *are* starting to use home solar (and other home renewables) in greater numbers. The price of home renewables is increasingly becoming competitive with non-renewable sources; I would expect that the upward trend will continue. As for low-density bio-energy solutions, the point wasn't to suggest that we'd have massive fields of plants generating power (or hydrogen or whatever), but that we'd be able to learn from the organic methods to construct systems which are more sustainable *and* more efficient.
Nessa -- there's a lot of good to be had with people actually giving this stuff a try.
Jamais - I agree the future's going to be a mix, but to me it's a very urgent problem, and I think we spend a lot of time focusing on and getting governments to fund solutions that will realistically solve at most a few percent of the energy picture.
For example, burning wood provided about 30 times as much energy to the US in 2002 as solar thermal and photovoltaics combined (see Energy Info Administration: http://www.eia.doe.gov/cneaf/solar.renewables/page/rea_data/rea_sum.html
) - I wouldn't consider any energy alternative "competitive" unless it's at least competitive with the "burning wood" level as a resource.
In fact, rather than "trending upward" at least for 1998 to 2002 from the EIA's tables, solar power production dropped from 0.070 quads to 0.064 quads. This seems to contradict the EIA's own numbers on increased production of solar modules; the explanation must somehow lie in shortened lifetime in use (or useability) of the new systems. Not a good sign.
Even 10's of thousands of people doing something does not make it significant. 100's of thousands of people supported Howard Dean... Or as they say, "million to one odds happen eight times a day in New York City".
It's a big world we live in; the energy issue is a big problem. If we're intent on changing the world, we need to be thinking about the big, trillion-dollar-scale solutions. Maybe these two technologies you outline can make a difference - but not if we keep piddling about with them the way we have - we have to face up to the significant commitment and, yes, sacrifice (ready for tax increases and GM crops?) they imply.
I don't mean to be completely negative; I'll send you something on what I think should be considered seriously soon :)
My friend and I have tryed splitting water into its base elements, and it does work. We are currently coming up with a more efficient method of doing so.
But what I wanted to say was that we were mucking around one day, and figured that we should see if we could get a low voltage reading. We tried and, I actually works! We got up to 1/4 of a volt out of one.