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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
Bring a product to market with all your so-called cheap abundant technology that never seems to pan out. I'm getting pretty damned tired of hearing about all these "advances" when nothing ever comes of it.
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.
Because PETE performs best at temperatures well in excess of what a rooftop solar panel would reach, the devices will work best in solar concentrators such as parabolic dishes, which can get as hot as 800 C. Dishes are used in large solar farms similar to those proposed for the Mojave Desert in Southern California and usually include a thermal conversion mechanism as part of their design, which offers another opportunity for PETE to help generate electricity as well as minimize costs by meshing with existing technology.
The fact that it is twice as efficient as a PV system is completely irrelevant, given that it will be competing with solar concentrators not PV systems.
Possibly one could try using a small panel surface with a lens pointing to it (if lenses are cost effective in this scenario) so even places up north could benefit. Way interesting.
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
I get the impression from the article that this tech would be impractical outside of situations where parabolic mirrors are not being used to focus the sun's energy onto such a solar cell. That makes it mostly impractical for everyday use.
File under 'M' for 'Manic ranting'
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.
While most silicon solar cells have been rendered inert by the time the temperature reaches 100 degrees Celsius, the PETE device doesn't hit peak efficiency until it is well over 200 C.
Because PETE performs best at temperatures well in excess of what a rooftop solar panel would reach, the devices will work best in solar concentrators such as parabolic dishes, which can get as hot as 800 C.
So 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.
Solar concentration requires big expensive equipment - Mirrors or Lenses.
If they could find a way to push this technology into the 100-150 degree range (thereby eliminating the need for concentration) and STILL maintain the 50% energy extraction the potential benefits are huge.
Sig Battery depleted. Reverting to safe mode.
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%.
With hydrocarbons, energy consumers pay for their energy a little at a time. With clean technologies, a large up-front investment is made, which pays for itself over a period of many years.
Most energy consumers can't afford the initial cost... And if they get a loan, interest costs eat up any savings that they might have gotten.
One small engineering advancement will make the energy companies obsolete.
Learn the rules so you know how to break them properly.
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I agree. I was going to reply and say the exact same thing. I'm sick of hearing about solar breakthroughs because nothing has been done to make this technology both affordable and practical for a homeowner. 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.
I'd love to find a conspiracy theory in this, such as oil companies purchasing the patents and never developing the technology. Sadly though, I suspect much of it can be attributed to overzealous researchers who don't understand practical manufacturing, deployment and maintenance concerns.
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Take a solar cell and slap one of these babies on it http://www.johnsonems.com/?q=node/2
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.
They aren't the only ones working on this process, I know a few others. Also, thermal and PV processes have been combined successfully before, unlike the claim in TFA - my own work centers on CPVT (Concentrating PV/Thermal) collectors. You can reach 40-50% efficiency like that. (Hell, you can get close to 30% just with triple-junction PV).
Look for papers by Abraham Kribus if you're into it.
Reading these stories is like getting my ass beat by a dominatrix, then discovering I've forgotten the "safe" word. Hey, it was cool when you started but it's not fun anymore. Seriously. Please stop.
I swear to God...I swear to God! That is NOT how you treat your human!
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.
Its a new month. Along with the new month comes the "Latest and Greatest" in solar power innovation, this one far far more revolutionary than last months... We had electron dots, last month, we had microscopic cones capturing UV as well as thermal a few months before..... I go to the store and am looking at 25 year old technology. I know 'to market' is the hard part, but at what point will all of this innovation, magic and wonder actually be ready to buy? Is it like Tokamak reactors, 30 years for sure, and at any time in its 60 year history, there wasn't a month that went by when it was only another 30 years or 'just 30 more years for sure'. Unfortunately it was a relativistic estimate. As you get closer to a firm, fixed date, time slows down. In time that can be perceived, its always 30 years. Its almost like one of Zenos paradoxes. Hello solar, we will all be using you, some time in the one-of-many-possible future universes.
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."
Do you mean compete with oil's fair-market price, or the price after all the subsidies that the U.S. government supplies for oil production, including the military cost?
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.
Please do not read this sig. Thank you.
They also don't have to be big. Fresnel reflector for example. Bog standard flat mirrors, arranged such that they reflect onto a focal point. Make the mirrors out of perspex and it's cheap and light as well as easily fitting onto a roof. You get a large mirror with a low profile, and can almost put the focus where you like.
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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
The memories of a man in his old age are the deeds of a man in his prime - Floyd, Pink
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.
just build a hydroelectric dam in your backyard like I did, everyone knows relying on the grid isn't practical for everyday use.
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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To correct the gp : In the Quebec province (Eastern Canada) as of 2008 : 95.6% of electricity is from hydroelectric sources.... and climbing. (Source Wikipedia)
"Solar water heating or solar hot water is water heated by the use of solar energy. Solar water heating systems are generally composed of solar thermal collectors, a water storage tank or another point of usage, interconnecting pipes and a fluid system to move the heat from the collector to the tank. This thermodynamic approach is distinct from semiconductor photovoltaic (PV) cells that generate electricity from light; solar water heating deals with the direct heating of liquids by the sun where no electricity is directly generated."
Basic glass-covered box + copper pipes (flattened inside the black-painted floor of the box) + water collection barrel combo has long been an important alternative technology feature in the developing world.
So soon one could tack one of these new-fangled Stanford solar/heat panels at the bottom of the box and besides photon conversion also harness the high temperatures for increased electricity generation.
I truly hope that this tech doesn't become a patent pissing contest but it is made available and even manufactured around the world without licensing impediments. Maybe the world's governments could step in, enumerate the inventors appropriately and make sure these crucial technology alternatives to fossil fuels become widely available and in massive quantities.
Should invading one's peaceful neighbours be opposed, or rewarded with trade deals?
The solar flux consists of electromagnetic radiation. Electromagnetic radiation is not heat. The sun does not radiate heat.
This novelty looks remarkably like just adding a thermocouple, which has never been any good at turning heat into electricity.
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.