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Stanford's New Solar Tech Harnesses Heat, Light
An anonymous reader writes with this excerpt from a Stanford news release:
"Stanford engineers have figured out how to simultaneously use the light and heat of the sun to generate electricity in a way that could make solar power production more than twice as efficient as existing methods and potentially cheap enough to compete with oil. Unlike photovoltaic technology currently used in solar panels — which becomes less efficient as the temperature rises — the new process excels at higher temperatures. ... 'This is really a conceptual breakthrough, a new energy conversion process, not just a new material or a slightly different tweak,' said Nick Melosh, an assistant professor of materials science and engineering, who led the research group. 'It is actually something fundamentally different about how you can harvest energy.' And the materials needed to build a device to make the process work are cheap and easily available, meaning the power that comes from it will be affordable."
The abstract for the researchers' paper is available at Nature.
Can anyone point me to a good cost/watt chart over time? I would love to be able to see how prices have dropped over the past two decades. I keep hearing that solar has to drop in price... but have no baseline to judge our progress.
See my journal for slashdot ID's by year. Mine created in 2005. http://slashdot.org/journal/289875/slashdot-ids-by-year
This is not intended for home/standard use. See below:
From the article:
What I want to know is what mechanisms are causing their Gallium-Nitride junction to conduct more reverse current above 227 C.
They are currently projecting operating at 200 C for max efficiency but if it's as I suspect -- increased current flow with higher temperature -- then they can modify the doping mixture to get even higher temps and therefore higher efficiencies.
This would also boost the Carnot Cycle efficiency limit for the secondary heat exchanger that operates after the GaN primary power generation.
I'm reading from the slides.
pointing a magnifying glass at an ant? I call prior art!
There are 10 commandments: 01)Thou shalt love the Lord Thy God 10)Thou shalt love thy neighbour as thyself.Matt22:34-40
It seems like every 6 months there's some big breakthrough in Solar that will make it many times better than existing technology. As far as I can tell none of it ever makes it out of the lab and into the market.
Compete with oil? I'm going to guess that they mean with coal, as oil is rarely used as a fuel for power generating stations. Coal and natural gas, yeah, oil - not so much. In the U.S., anyway, only around 1% is generated by petroleum, whereas coal is about 45% and natural gas is about 23%.
Continue reading:
Melosh calculates the PETE process can get to 50 percent efficiency or more under solar concentration, but if combined with a thermal conversion cycle, could reach 55 or even 60 percent – almost triple the efficiency of existing systems.
Roof top glass enclosures (solar hot water) nearly achieve this all by themselves in some sunny locations. http://en.wikipedia.org/wiki/Solar_thermal_collector
Its contained in the collector. Its so hot you generally have to mix with cold water for household use.
Sig Battery depleted. Reverting to safe mode.
o still not practical for home roof top deployment. Most people will not want 800C )or anything close) on their roof tops even if it was light and portable.
Are you kidding? Add a couple of rotating mirrors and market it as a death ray. Rabbits getting into your garden? Neighbor's dog crapping on your lawn? Reflect that beam spot around and *poof*, no more problem!
Learning HOW to think is more important than learning WHAT to think.
Call me when I can pick it up at Home Depot.
When Fascism comes to America, it will call itself Anti-Fascism, and tell you to give up your guns.
Impractical for personal residence deployment and use, but I'd certainly call a big solar power generation station providing energy "everyday use". Or at least, I'd like for it to be an everyday use. Much like efficient windmills are much too large for my backyard, yet provide me with clean energy everyday.
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CSPV cells are one of the tech items that do in fact come to market. EMCOR and Spectrolab and others like Ammonix routinely bump their efficiency with new processes -- not just the efficiency of their "champion cells" but of their normal end product. In fact there have been upgrades done to concentrating PV plants whereby just by replacing the cells/heatsink, leaving all the dishes or whatnot untouched, they have increased output of the plant.
I feel like someone let my jet-pack fall out the back of the UPS truck, too, but not in this particular sub-area of solar PV.
Someone had to do it.
So if you could reflect the heat to generate power and use photovoltaics to generate power, could you also create them translucent to some spectrum of light? Then you could grow crops under the solar array, use the array for water capture so the irrigation would hold water better and provide power and temperature maintenance. This idea only works if photovoltaics and plants uses different spectrum to generate power/photosynthesize.
Thermoelectric looks obvious, doesn't it? A few years ago I thought how convenient it would be to use the waste heat from my Diesel boat heater to generate electric power, and I contacted a manufacturer. The reply I got was "we're not even going to quote you because it's insanely expensive". Apparently thermoelectric generators are so expensive they only make sense on things like trans-Siberian or Alaskan gas pipeline monitors, where there isn't enough light for a solar PV supply and the cost of miles of environmentally resistant wiring would be even more prohibitive. Although Peltier generators are cheap, they are hugely inefficient - and even more inefficient in reverse. It would have been cheaper to cover the entire deck in solar panels.
From scarped cliff or quarried stone she cries "A thousand types are gone, I care for nothing, no not one."
I live in one of the better parts of the country for solar power, and an installation would cost more than $15,000 to even begin to be practical.
What part of the country is this where putting 15 grand in to your house is such an outrageous sum? A new roof, HVAC, siding, remodeling a room.. pretty much anything you do to your house is going to have a similar cost. And I guarantee none of them would give you the same return until you sell the house.
Whale
Ditto. I'm getting truly sick of these "improvements in solar technology" stories that turn out to be little more than research lab oddities, penny stock scams, or something so expensive that it will never be commercially viable.
When it looks like Joe-Bob can buy a system for under a thousand at Wal-Mart, and the system is so idiot proof, that even Joe-Bob can plug it in and make it work without killing himself or burning down the trailer, you have something.
Until then, even if it works, solar is still just a rich man's toy.
Solar energy. It's NOT just a technical problem. It's an economic problem.
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This seems to be the new scam for this decade. Your company/university/research-lab accounces a "breakthrough" using commonly available, cheap materials that "somehow" provide energy because the arrangement of these materials is the part no one has thought of before.
We've got: EEstor with their "ultracapacitor", Bloom Energy with the "Bloombox", Stanford's now got their Solar Gen whatever it is, there's the Science Fair Kid that made a 30% increase in PV efficiency, yadda yadda... Hell, a few weeks back even the Chinese announced a "new solar product" that was supposed to be more efficient...
Someone should go through the last 5 years of Slashdot and pull up all the articles about new energy technology and where they announce it will be available in stores in 5 years time, and let's see what the claims are versus what reality has brought us.
Because so far, all I ever see in stores or online is the same old crap that's been available since forever, plain old 12% efficient silicon-based PV panels, where you still need $2000 worth of them to run a fridge.
If telephones are outlawed, then only outlaws will have telephones.
The progress report from March 2010, available at http://gcep.stanford.edu/research/factsheets/petesolor_results.html, provides a more detailed and understandable summary of what they are doing
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Even if the tech gets to a point where Joe-Bob can buy a 5,000 watt solar array at Wal-Mart for $999, he won't be able to install it permanently in a safe manner, because you're still dealing with 5,000 watts. It becomes nothing more than a fuel-less generator. Mounting it permanently on his roof, tying it in to his household wiring and setting up a grid-tie net-metering arrangement will still take the work of professionals.
Of course, we may someday get to a point where the process is simplified and routine enough that installation costs might approach something like putting in a tankless water heater, gas lines or satellite dish.
Not necessarily, parabolic trough concentrators aren't that exotic, there are many DIY examples on youtube.
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Somewhere around 60% of our electricity usage is simply moving heat around. Either producing it where it's cold or removing it when it's hot. There are far more efficient and cheaper ways to do this.
http://www.eia.doe.gov/emeu/reps/enduse/er01_us.html
Stop the heat moving; insulate everything. Internal and external walls. Roofs, floors, refrigerators/freezers. If not vacuum panels, research into the production of really cheap aerogels for building, DIY materials and domestic devices would probably do more to reduce electricity usage and bills than solar panels.
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Hi all. I'm one of the researchers on the project. As they say on Reddit, Ask Me Anything. I'll do my best to answer everyone's questions.