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Solar Power Becoming More Affordable
prostoalex writes "With both startups and large companies such as Boeing working on solar power, the technology is becoming more affordable, MIT Technology Review says. Solar power concentrators are all in rage now: 'The thinking behind concentrated solar power is simple. Because energy from the sun, although abundant, is diffuse, generating one gigawatt of power (the size of a typical utility-scale plant) using traditional photovoltaics requires a four-square-mile area of silicon, says Jerry Olson, a research scientist at the National Renewable Energy Laboratory, in Golden, CO. A concentrator system, he says, would replace most of the silicon with plastic or glass lenses or metal reflectors, requiring only as much semiconductor material as it would take to cover an area the size of a typical backyard. And because decreasing the amount of semiconductor needed makes it affordable to use much more efficient types of solar cells, the total footprint of the plant, including the reflectors or lenses, would be only two to two-and-a-half square miles.'"
This headline can be recycled and reused into perpetuity. Chances are with continuing advancements it will always become more affordable than it was last week, month, year, decade, or century.
But when will it become truly affordable for the masses? That's what most of us want to know. Wake me when it's time to disconnect from the petroleum/nuclear fired grid.
"It's the height of ridiculousness to say for those 9 lines you get hundreds of millions."
Why all the talk of centralized power generation?
:p) energy would a fraction of what it is now.
Solar panels are the way to put power generation into the hands of the people. When I look out at all the rooftops in the area - houses, office buildings, Super S-Marts and their enormous un-covered parking lots, all I can think of is if every one of those surfaces had a single solar panel our energy demands from centralized (corporate
Have we learned nothing from decentralized computing?
years. One of the major problems of concentrated solar power is the heat - normal photovoltaics would melt. The benefit is that concentrated light also has better efficiency than the normal ~10-22% of normal solar power. One of the traditional ways around the heat problem wasn't to use a photovoltacic as all. An energy farm in Australia uses dishes to focus the light and at the focal point places a stirling engine, with only the heat powering it. Interesting stuff. I hope to have my own workable solar power system power my property one of these days.
Americans vote Democrats control of our government, and suddenly 3 days later solar power could be affordable. When they actually take power on 1/3/2007, will we finally get our goddamn flying cars?
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Such concentration systems are usually coupled with thermal applications:
-you increase the overall efficiency of the system (up to 80-90%) by getting both electricity and heat
-you heat water while cooling down cells, which improve their efficiency too (you can get as much as 30% with germanium)
http://www.solartecag.de/sites/innovation.htm
The problem with all these "The Big Bad Industry doesn't want X to succeed!" is the absolutely staggering number of X's that have nonetheless succeeded. Who cares what my power company "wants"? If I could buy cost-effective solar, I would. I can't. (And given that I live in cloudy Michigan it's going to be even longer for me than for some of you, but that's just a detail.)
Good luck to any power company foolish enough to stand in the way of something with the PR power of solar power. Can you imagine the media bloodbath that would ensue if any power company executive even mumbled something about getting solar outlawed?
Seriously, less emotion, more brain. It's the Universe making solar power hard, not a conspiracy of apparently-omnipotent "evil executives".
Your model (a heat engine) doesn't really work for solar cells, although you are certainly correct that 100% efficiencies are unobtainable.u ll-spectrum-solar-cell.html
In solar cells, the point is that photons excite valence electrons across a barrier, giving them enough energy to create a current. There isn't really a classical analogy for this effect.
There's a limited discussion of solar cell efficiencies here, although it doesn't talk much about the underlying physics:
http://www.lbl.gov/Science-Articles/Archive/MSD-f
The upshot is, cells of a single type of material can only get up to about 30% efficiency, but we can stick several materials together to get past that barrier.
What a horribly foolish and short sighted statement. While it is true that solar works when the sun shines, it also works when it is cloudy, albeit producing less power. Therefore the average annual power production of solar is dependable on an annual basis.
Power storage for solar can come in many forms. For a solar-thermal system (i.e. a stirling engine generator) you can simply store the heat using one of many mediums. For a photovoltaic system you can store the power using batteries, capacitors, hydrogen, heat, or even gravity by pumping water uphill. While the last three require a hybrid power system to access the stored energy (PV->H2/heat/gravity->electricity) they are not new technologies. In most areas you won't want a single power generation system so you'd have multiple plants anyway. The solar-thermal systems are particularly compatible with stored power as they work under direct solar energy, stored heat, or any combustible fuel (coal, wood, ethanol, petroleum, etc). And a solar/hydrogen power plant would double as a power source for hydrogen vehicles.
While it is true that areas closer to the equator see more power generation capacity from solar, even areas farther away still benefit from solar's ability to mitigate peak demand in summer and winter.
The cost of solar (PV or thermal) eliminates the almost incalculable secondary costs of conventional fuels (impacts on asthmatics from particulates, acid rain, ecological damage from mining coal or spilling oil, etc).
I've been on slashdot so long I'm starting to get out of touch with the cool stuff if it ain't on slashdot.