Slashdot Mirror
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.
Let's see, four square miles of sunlight focused onto my back yard. Conversion efficiency ~30%. Melting point of silicon 1414 deg C.
Unless I've got a backyard the size of Bill Gates, lifetime of new solar plant = one sunrise.
"It's the height of ridiculousness to say for those 9 lines you get hundreds of millions."
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?
--
make install -not war
They are, only problem is that you can't know both what their position is on an issue, and how fast they want to implement it.
Also, I think they have a dead cat, or something....
Slashdot Burying Stories About Slashdot Media Owned
Then again, they could just reorganize and move into the manufacturing and maintenance side of things. Someone will have to fix and maintain the solar homepower systems ultimately. The one major advantage of having a power distribution grid, though, is the ability to redistribute power. If Sunville, AZ is having a month of sun with no clouds, and it has been cloudy for a month in Bad Ass, MS, the energy can be redistributed so that all of the Badassian's batteries don't run down.
-b.
One thing I really wish would happen is that the efficiency of thermovoltaic technology could somehow be improved... Think about how much energy is wasted as heat; eventually all of it, I suppose. I actually heat my bedroom in the winter with my PC. When I read about large scale solar facilities, I can't help but wonder at the losses in heat that are going on there. There are more efficient ways of utilizing solar power right now anyway: http://www.stirlingenergy.com/ comes to mind... and they work pretty well. It would be nice, however, to move the technology to solid state like we have with photovoltaic cells; That way we could apply them to things like brake shoes on cars, the condensers on refrigerators and air conditioners, etc... -Photovoltaic paint has been invented, but is not realistic yet. I think that's where the future is: Objects that need electricity should become more efficient, and should have photo/thermovoltaic technology built right into them.
-ubuntu others as you would have others ubuntu you.
Part of the problem is the durability of these panels. The affordable ones have relatively short lifespans (under 10 years, and at that point, still haven't saved enough to justify their cost). The ones that ARE durable enough to last longer are hideously expensive, and not the sort of thing most people have the cash for.
Also, there's the fact that solar power is not a viable solution everywhere in the world. Sure, in Arizona, California, etc, it is a wonderful "free energy" thing.
In Pacific Northwest, the northern Midwest, etc, especially during the winter months, solar power is a complete non-option.
Chas - The one, the only.
THANK GOD!!!
Let's just say that it costs a super cheap 20$ a square foot. The cost of the mirrors alone would be $1,115,136,000.
Wow. I can make up numbers too. Let's assume it was a "super cheap" $2 a square foot. That's only
$115 million. Oh wait, let's assume it's only
Rather than pulling numbers out of your ass, maybe you should have real estimates of what it costs to make a plastic mirror. Considering you can make wood flooring for
AccountKiller
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".
Actually, a heat pump is a bad example, since you're putting energy in to move heat, not moving heat and getting energy out. With an engine, the amount of heat moved always has to be greater than energy out. Same with a heat pump - you actually can move more heat energy than you put power in. Hence coefficients of performance greater than 1.
-b.
You'd be amazed what can be done without proper design. Last year after the natural gas price spike, my wife went on a nut and turned the heat down to 55 for the winter. I'll admit it was a bit chilly at times and sweaters or sweatshirts became our casual dress around the house but by just opening and closing drape at the opportune times, we could keep the house above 65 during the day, above 62 during the evenings. We found it was more comfortable to shower with the bathroom door closed.
Apocalypse Cancelled, Sorry, No Ticket Refunds
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.
I've worked a lot with photovoltaics. They're really cool, but I recognize their limitations for utility-scale power generation. The primary limitation is that silicon-based photovoltaics currently convert only 10-23% or so of the incident solar power into useful electricity. Silicon solar cells cannot convert infrared light to electricity - the photons have too little energy. Higher energy photons (visible and UV light) are poorly utilized - a solar cell will get the same energy output from a red photon as a blue one, despite the fact that the blue photon has higher energy. Solar cells aren't very reflective (by design), so most of the remainder of the unconverted sunlight becomes heat in the cell.
You can get higher efficiencies by going to other chemistries, like GaAs, and by layering different chemistries on top of one another. These are not cost effective, and won't ever be able to get above, say, 50% efficiency.
But solar energy is not limited solely to photovoltaics. Probably the best way to use solar energy is solar thermal - capture all that 1000 W/m^2 of incident sunlight as heat. It can be used to heat a fluid up to fantastic temperatures, which can drive turbines, etc. This is the principle behind Solar One, Two, and Tres and the Nevada Solar One plants. These are, however, demonstration plants, not utility scale.
The other major kind of solar energy is biomass. Photosynthesis is a pretty good way to capture sunlight and make it do something useful. Plants have had a looong time to get good at making use of sunlight, which we use to our benefit in many ways. When cellulosic ethanol comes around, you'll probably make better use of sunlight by planting crops and building a solar power station.
First building a proper and efficient home is extremely hard to do.
1 - they are "ugly" to most people that want the cookie cutter that looks like the other 15 homes in the new subdivision.
2 - They require more land than the typical suburbian/urban lot offers.
3 - Actually paying for low-e glass + correct design + insulation is expensive! They would rather have cherry cabinets, stone fireplaces with a plasma TV above it than energy efficiency.
4 - building from real materials is also insane expensive. I live in a all brick and Stone home now that is from the 1950's It's beautiful and would cost nearly $1,000,000 to build today. The stonework is real the brickwork is real my walls are 2X6 and then have the stonework on the outside giving me 10-12 inch thick walls, new mansions dont have real stone anymore, they have the faux or created stuff that is in reality only an inch or two thick even for their fireplace stonework (I have real marble and limestone) so building the home to have real thermal capabilities is not possible except for the rich.
5 - efficient materials like adobe is illegal most places, an adobe home is incredibly efficient.
6 - efficient designs are hard to get approved by the association... Any home that looks different is considered ugly. Domes are the absolutely most efficient. I had one that during some winters was self heating due to the sliders and skylights to the south. Paying $85.00 a year for propane for heat is really stinking nice(1999-2002)
The common person cant have an efficient home, they cant afford it. Jsut like solar and alternative energy. No average joe can float $5000-8000 for a basic solar install that will pay back in 10 years saving few dollars here and there.
Do not look at laser with remaining good eye.
You forget the five Solar Thermal plants at Kramer Junction which together produce 165 MW. SEGS III - VII, as they are called, have been in commercial operation for around twenty years now. These are definitely utility scale plants, not demonstration plants.
Aren't they the party that proposes setting national policy by a daily horoscope? That would make the United States a Cancer...
(Stop that snickering, you in the back!)
Strike while the irony is hot! -- The Freethinker
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.