The day is not here yet, but soon will be, when connecting homes to central power grids will be unnecessary. By "soon" I mean within 20 years. Here's why.
"New Solar Photovoltaic Cell Efficiency Record: 42.8%." Once solar-cell efficiency reaches 50 percent, quite a large amount of electricity can be generated from much smaller areas than at present, making rooftop solar cells powerful enough to supply electricity for the whole home. Fifty percent is the efficiency rate set by the Defense Advanced Research Projects Agency (DARPA) at which solar-cell sets become portable enough to be militarily useful for tactical units.
So I think that the day will soon come when solar-cell technology will reach that 50 percent mark and manufacture of such cells will be cheap enough so that roofs of houses may be covered in them. Central grids won't go away, not soon, anyway, because solar roofs will still be more expensive than shingles, but excess electricity from solar-powered homes will be sold to the grid to help provide juice to conventionally-powered homes. Furthermore, businesses use more electricity than homes and even at 50 percent efficiency, solar cells probably won't be able to power businesses in full.
The question is begged, however: what about nighttime or very cloudy days? How will homes be powered then? Aha:A new type of a room-size battery, however, may be poised to store energy for the nation's vast electric grid almost as easily as a reservoir stockpiles water, transforming the way power is delivered to homes and businesses. Compared with other utility-scale batteries plagued by limited life spans or unwieldy bulk, the sodium-sulfur battery is compact, long-lasting and efficient. ...
American Electric Power (AEP), one of the largest U.S. utilities, has been using a 1.2 megawatt NaS battery in Charleston, W.Va., the past year and plans to install one twice the size elsewhere in the state next year. Dozens of utilities are considering the battery, says Dan Mears, a consultant for NGK Insulators, the Japanese company that makes the devices.
"If you've got these batteries distributed in the neighborhood, you have, in a sense, lots of little power plants," [analyst Stow] Walker says. "The difference between these and diesel generators is these batteries don't need fuel" and don't pollute.
There is no reason that such battery piles couldn't be built into homes themselves, making a home entirely self sufficient for electrical power. But economies of scale would almost certainly mean that homeowners would find it cheaper to tie into a neighborhood battery pile, which would store the combined excess power from home during the day and provide it back at night or other low-solar times. In fact, it's not hard to envision homeowners associations starting electrical co-ops for that purpose. Battery piles, of course, can store electricity not only from solar cells, but from any other generating means. In some parts of the country that could be a boon to wind generation and can even reduce the amount of coal that coal-fired plants use by storing power from peak-generation times.
A final thought: is 50 percent solar cell efficiency high enough to make pure-electric autos self charging? What about hybrids, which use the gasoline engine to recharge their batteries; could they use highly efficient solar cells instead, thus decreasing their use of gasoline? I don't know, but I'm sure some smart people are working on the answers.
Some facts, today:
the cost of a solar-cell-produced kilowatt-hour: 60 cents
the cost of a nuclear-produced kilowatt-hour: 3 cents
It is a long way to go for solar power.
BTW, NaS batteries may solve some of the problems of regulation of wind energy, which is a constant headache (and a big cost) for grid operators, but take into account that in some places in the world, like Europe or China, room in or near urban areas is very expensive. Evidently, superconductor devices that can transport or convert the same energy in much smaller devices are a far better solution there.
J is dead on. The technology is fascinating but we have long way to go before economic viability.
20 years is an awful long time. It's equally probable that by then America might have finally gotten over the slander against nuclear power and have inexpensive and plentiful electricity. And, as a by-product of having lots of surplus electricity in the evening hours, we'll have plentiful hydrogen capture capability, thus enabling the "hydrogen economy."
I think I'm more interested in the SaN battery technology...
What is the production capacity for these new solar cells? And for the NaS batteries? These important details have to be considered before mass use is possible.
But perhaps we're approaching the point where solar energy conversion and electricity storage are adnvanced enough to make solar energy a serious alternative.
In case people hadn't seen recent discussion of other solar develoments:
http://www.sciencedaily.com/releases/2007/07/070719011151.htm
Currently, the technology is at 1.7 percent efficiency and about 0.7 volts of electricity. Researchers think they can bring it to 10 percent.
It would seem to me that advances in battery technology would make nuclear energy less competitive. If we can get by with our current electrical generating capacity by redistributing power generated at off-peak hours to peak hours, then few, if any, new plants will be built.
As long as the energy Luddites refuse to build nuclear plants, we will be reduced to the "alternative technologies" nonsense. The solar, wind, geothermal, moonbeam, etc. technologies will never be more than a supplement and a fashion statement. Hydroelectric power options are pretty much tapped out.
Nuclear power is the only technology that generates its own fuel. America should begin generating electricity with nuclear plants and phase out coal and natural gas plants, as these fuels can better be utilized elsewhere in an intelligent power program. It should abandon the idiotic ethanol program (which is taking food out of people's mouths as well as being completely inefficient) and begin to process coal and oil shale into fuel and lubricants. We should begin drilling domestic oil wherever economically feasible and upgrade and expand our domestic refining capacity.
Nuclear or no nuclear, solar is a technology of the future. Even if we do control cold fusion, it is unlikely that it will be as cheap or easy to produce cells or small units as solar will be by that time. The trouble with it would be too much power - I would predict solar tech keeps slowly advancing and is used (as was suggested) like wind and hydro as a supplemental tech. The battery tech looks nice, but I've yet to see many communities organized enough to do something like that.
And again, it all depends on how big the new power generators are, and how controllable their rate of output. Purdue suggested they might be able to make relatively tiny cold fusion cells a few years ago, but whether or not their ultrasound + heavy water cells are even viable is still uncertain. Solar is a real tech that is gradually improving.
I've already seen a few electric road signs (and other equipment) that have a solar cell attached. May never be economical on a grand scale, but there's no questioning its amazing utility.
What is the effective usage life of the battery?
How much energy is utilized in its material development and fabrication?
What are the associated Operations & Maintenance (O&M) costs?
What are the long term waste implications during usage or following its end-of-life disposal?
What other costs are associated with the necessary support infrastructure (e.g., switchgear and controls) to accomplish the installation and use of the battery?
As J Aguilar makes the point: solar is 20 times more expensive tha nuclear per kilowatt hour.
How many gigawatts can a solar plant generate?
/snark
Solar will always be a supplemental source useful for only small instalations in sunny locales.
To date cold fusion is science fiction. Nuclear fusion is extremely hot and to date has proven unstable in magnetic containment, and this on a laboratory scale. Relegate fusion power to the Star Treck file for the foreseeable future.
The sodium-sulfur battery is not new. Google it and you will find that it has been around for a while. I remember being a child on a late night trip (35 years ago?)and it being discussed on talk radio by an engineer promising that it would solve all of our energy storage problems. Like MHD, the problem isn't that it won't work, the problem is material science. Molten sodium and sulfur tend to eat through a lot of things. The failure modes can be catastrophic. New materials technologies seem to overcome a lot of the corrosion problems. I hope that the promised lifetimes are true, that the prices come down, and that the enviro-nuts don't kill it.
If personal power generation works, whenever it works, the decentralization of power generation will greatly decrease the vulnerability of the US to attack, by terrorists or other enemies. The Internet was created to decrease the vulnerability of our communication capabilities by eliminating central bottlenecks. That has worked, and there have been lots of extra benefits (like blogs!).
Today, we're at the stage of reading research results that promise future developments. It's a bit early to ask about mass production rates and such. Presumably, as a society we are pursuing a large number of alternate possible energy solutions. Sticking to just a few is self-destructive.
As to nuclear, it may be a piece of the puzzle if there is enough government subsidy and protection, but it seems unlikely ever to be viable as a business. I don't see any way, in the visible future, for the nuclear industry to pay for either its own waste disposal or its own liability insurance. Without those, it's not a viable business. If it's justified as part of the national defense portfolio, it doesn't have to be viable as a business. Just accept that it will always require subsidies and protection.
_from J Aguilar at 4:42 pm on Jul 26, 2007
Some facts, today:
the cost of a solar-cell-produced kilowatt-hour: 60 cents
the cost of a nuclear-produced kilowatt-hour: 3 cents_
Is their a reference for these numbers? How much per Kilowatt-hour does a coal cost?
This energy debate is usually discussed with few facts and a lot of wishful thinking.