A California startup, with strong venture backing, says it can slash the cost of solar power with its concentrator technology.
Focus enough sunlight on a sheet of paper and you can light a fire. Focus the same sunlight on a solar cell and you can generate plenty of electricity. That strategy for increasing the efficiency of solar power is, as Palo Alto, CA-based startup SolFocus demonstrated last week, one of the hottest trends in alternative energy. SolFocus, which has secured $25 million in venture capital financing to accelerate development of its concentrator photovoltaics, employs mirrors to focus sunlight 500-fold onto high-efficiency solar cells.
SolFocus's second-generation solar panels cut costs by reducing the amount of photovoltaic material needed. They employ quarter-sized mirrors that focus sunlight on photovoltaic "dots" just one millimeter square. (Source: SolFocus)
Concentrator technology to increase the output of solar power is not new. But thanks to high-efficiency photovoltaics and novel manufacturing techniques that create better solar cells, lenses, and mirrors, concentrator photovoltaics systems are delivering more power at lower cost.
At the same time, double-digit growth in demand for solar power systems is outstripping the ability of manufacturers to keep pace, given a tight supply of silicon for conventional solar cells and the high cost of the equipment needed to produce them (see "Large-Scale, Cheap Solar Electricity").
The technology has the potential to lower costs because it uses a fraction of the semiconducting materials that convert light into power in photovoltaics. Most of the cost is in the lenses or mirrors to focus the light and tracking equipment to keep the device pointed at the sun -- elements that are more susceptible to economies of scale than silicon production. "Coming from the semiconductor industry, I knew we could never scale up the amount of silicon we'd need to make a material dent in world energy demand," says cofounder and CEO Gary Conley.
SolFocus' design, for example, uses one-thousandth as much semiconductor material per watt produced as a conventional silicon photovoltaic cell. The technology uses compound photovoltaics such as germanium and gallium arsenide, originally designed for use in satellites, which can capture up to 40 percent of the solar energy hitting them -- more than double the efficiency of high-end silicon cells.
But the bulk of the materials reduction comes from the concentrator, which Conley says resembles the headlight in most modern cars. "Put the cell where the light bulb is and you have our design," says Conley. Mirrors are the key: a primary mirror that focuses sunlight onto a smaller mirror perched above, which, in turn, focuses the light on the solar cell.
SolFocus' current, first-generation design molds an array of 635-square-centimeter mirrors into a glass plate. Secondary mirrors attached above them reflect light through holes in the plate onto one-centimeter-square high-efficiency cells below.
Guest (jonathan)
The technical points kitk mentions are valid. It will be interesting to see how the tracking mechanisms withstand. This company will have to contend with many competitors indeed. Some examples of competing technologies are spray on photovoltaics, nanocrystals, and perhaps most interestingly, quantum dots, which have been reported to displace 6 (or 7?) electrons for a single photon. I imagine that this market is going to heat up like the sun in the next decade. Enough of the bad puns, time to bask in the sweet rays of technology.
Guest (Rob)
One of the big problems with solar power besides cost is the physical space needed. I don't know the figures for W/m^2, but I know that a Gigawatt installation would be pretty big. However after reading the article about cheaper IR detectors, I wondered if quantum dots might make cells more efficient and thus smaller but reacting to a broad spectrum of photons, rather than a narrow band. Thoughts?
Thanks,
Rob
Guest (dennis)
QD enhanced solar cels are already under development and showing promise.
Guest (Amulek)
Solar power is still for suckers, and will be for a long time.
Guest (Bravid)
Yes, very good point. I particularly like the way you have explored the point in such detail leaving little for anyone to disagree with. I think we need more explainations like yours. Have you considered a career in teaching or diplomacy?
Guest (Tysto)
...told Henry Ford to give up. After all, no one would want an expensive, dangerous, and dirty vehicle that you have to crank to start. Thanks, Amulek, for reminding us that no one should try to invent anything.
Guest (Sean)
I agree. In fact *infinitely* long, if no one persues it.
Guest (Jonathan 2)
We are just reinventing the wheel?
Knock, Knock are there any working brains out there?
Guest (Bill)
Read the article on Geothermal
Geothermal is the most promising alternative source for energy. IT is constant, is virtually inexhaustable, and if not bungled by bureaucrats, can be very inexpensive.
Guest (Chris)
I don’t think the bureaucrats will screw it up (much), but the “Earth Mother” crowd already sees geothermal development as Gaia rape. The myths are out there already, the best one so far; “Using the Earths crust to heat water will cool the core & destroy the planet”. Any large scale geothermal implementation will have to go through the courts.
Guest (Jonathan)
Geothermal is certainly a promising tech primarily due to it's constant energy supply. PV on the other hand, does have some advantages.
One of the strongest advantages of PV is it's distributed energy supply. Already our energy grid is overwealmed with the energy demand. I have been talking with customers throughout the US that are getting blackout warnings due to the large use of air conditioning. The surges of energy use are primarily during the day, when the sun is hottest.
PV technology can suppliment existing energy technologies and is certainly complimentary to existing technology.
Future generations of solar technology are developing rapidly and I wouldn't be surprised to see PV cells getting > 50% efficiency relatively soon.
Guest (kitk)
practically speaking, someone will ALWAYS try to stop any new developement--even if helps us all. Geothermal will attract luddites, and remember this: it requires a large steam plant to run. PV can use inverters to attach to any home's power.
Re: Read the article on Geothermal
This is ridiculous. Solar IS inexhaustible, it is available and predictable worldwide, including oceans, the atmosphere and space, it causes no emissions, it recoups it energy cost in a few months, and it's decentralized, i.e. doesn't need a grid. For all these reasons solar will take the developing world (where 90% of the world's people live) by storm, much like cell phones have. Once again it looks like the US will have to cede leadership of solar to Europe and Japan.
Guest (Frank Carraro)
Solar and geothermal not competitive
I agree geothermal should be the technology to pursue, but for off-the-grid applications solar can make a big contribution. Every home will not have its own geo-well 2 miles deep.
Guest (Bill)
The potential to have geo-wells (given tech advances) in more areas close to off-the-grid locations is very feasible
Guest (Keith)
Re: Solar and geothermal not competitive
I agree that solar and geothermal energy is not competitive in that their are limits as to how much energy transmission lines can carry. Home production of energy from solar during times when its most needed e.g.. "daytime hours" for cooling homes, can complement energy distributed across transmission lines. Solar doesn't seem like it can be a substitute, and at best only complement existing or future systems.
Guest (dmm)
Last paragraph of 1st page reads "SolFocus' current, first-generation design molds an array of 635 one-square-centimeter primary mirrors into a glass plate. Secondary mirrors attached above them reflect light through holes in the plate onto one-centimeter-square high-efficiency cells below." Shouldn't the high-efficiency cells be 1 mm squared?
Guest (Tysto)
I think the mirror array is 635 mirrors, each 1 sq cm, sitting over a PV cell that is also 1 sq cm. If they're 20% efficient at it, that accounts for the 500 suns GC mentioned above.
Guest (Tysto)
I meant the 635 mirrors need to be 80% efficient to focus 500 suns onto a like-sized PV cell.
Guest (Peter Fairley)
Our bad: The size of EACH primary mirror in the first-generation system is 635 square centimeters. My apologies for the confusion.
Guest (william eady)
A look on the sunny side of life
Just in case that any of our fire-loving Neanderthal cousins out there still haven't noticed, we are living in a 'solar system.' As 'Third Rock From The Sun,' our unique position in this relatively modest group of planets allows us to enjoy the virtually unlimited amounts of clean renewable energy that this mid-sized, type GO yellow star is capable of producing completely free of charge. If, in fact, we could harness the amount of energy which falls upon the earth contained in the form of sunlight in just one hour, it would be roughly equal to the same amount of potential energy created by the combustion of 200,000,000 tons of bituminous coal. Embracing the benefits that can result from using photovoltaic technology to our advantage is the wave of the future. Get used to it.
Guest (Neanderthal)
Did we time warp back to 1960? The technology to harness this "free energy" is not free! There are also those pesky things called clouds, smog and shadows. Oh and by the way photovoltaic technology has been the wave of the future since the 1930's.
How exactly do you figure that PV has been the wave of the future since the 1930's? The first solar cell was created in the mid 50's.
What exactly is your point? When did the Sun send you a bill? And so it takes a century to assure unlimited clean power for everyone. So what??
Guest (Mark Shapiro)
Looks like progress, and let's integrate solar . . .
This is one more line of progress. And the entire PV industry would benefit from 3 dimensions of integration:
1) architectural: PV panels become the roof or skylight, not just an add-on
2) electrical: DC from PV powers electronics directly, instead of converting to AC then back to DC
3) economically: realtime pricing for electricity matches PV supply to power demand. They both peak on sunny days!
Guest (Bruce Considine)
So what? We'll just lose this industry too.
Japan is already in there. With their government industrial policy they'll just muscle any US companies out of the way. One day it'll be just another technology that the US had a lead in but lost the industry due to piss poor or non-existent planning. The acolytes of the market will propagandize it as the best of progress. Meantime the rest of us will have to aspire to scaling the heights of hair styling.
Guest (BBTG)
The "Japan, Inc." argument is SOOOO 1980s.
"The 'Japan, Inc.' argument is SOOOO 1980s."
If that's really what you think, you have not done your homework. Read the recent scholarly work on this topic. The rise and fall of nations grinds out over generations. To assign it to a decade simply because it was a hot media topic is... myopic.
Guest (Mike)
Losing this Industrial Opportunity
This November you can send a message to our leaders that we need systems like this to offset our poor national power grid. As for Japanese (or Asian more correctly) we can stand up to them, organize our bsinesses and make sure US products are used here as opposed to importing them. Afterall. Even if the panel is made overseas by a US corporation, you still need to have a local-boy (or girl) install them.
Lets face it - our US infrastructure absolutely sucks! Its obsolete, over burdened and on shakey ground. Our roads and bridges are buckling, rusting etc. Anything an individual can do to unplug from it will be better for the individual. We need a new political group in Washington that can take the New Deal Approach to building up our Nation again. Oh - I forgot! We already sold our steel mills to the Russians and Chinese and the local-boys really speak Spanish.
Novemeber can't come soon enough.
Re: So what? We'll just lose this industry too.
Totally... well put. But we'll always be tops in the technology of killing. Yell louder than hell and carry a big nuke.. worked for Truman, right? LOL.
Guest (GWB)
can we use it as a weapon to kill people with?
Guest (kitk)
sure, it's done all the time. called skin cancer. seriously, this focusing tech is for very small scale targets. a greater danger is from the electricity, should you get tangled in the wires. but everything is dangerous, so let us be bold enough to embrace our future.
Guest (Ron)
Another company makes Solar roof tiles
Open Energy.(OEGY) makes solar roofing tiles that can be installed by any roofer. They also make the SV panels. Open has a concentrator technology under development but it is for large power generation by heating and should be much better than using mirrors for that purpose.
As far as using solar, it is use renewables, lower CO2 or die. I guess that will make it economical.
Re: Another company makes Solar roof tiles
The pure 1st cost economics must make sense or no one will buy it. 2nd and 3rd level issues like CO2 build up dont factor in unless the primary costs are tied. (By the way, CO2 "global warming" can be very cost effectively controlled by placing a few hundred hectares of Iranian and Syrian soil into the upper atmosphere)
Guest (Ben)
Pictures or diagrams would help
When can I go to Lowe's and buy them? What kind of battery/inverter setup would I need to use them?
Guest (Green-Homes.com)
This technology is advancing quickly, so by combining nano technology with solar concentators, I predict solar will explode as prices drop in half and output doubles.
http://Green-Homes.com
Guest
How does one go about combining nanotechnology with concentrators? What do you mean?
Guest (Ben Wiens)
Concentrators don't work in cloudy weather?
Isn't it true that concentrators don't work well in cloudy weather. The suns rays are mostly scattered to the side and not on the solar cells? So would such a concentrator cell be only really useable in desert climates? That's a bit of a limited market?
There is also a problem of series resistance in concentrators.... Special care should be taken to reduce the series resistance of concentrator PV cells and modules.....
I created a poster that, among other things (global warming), depicts the Earth as 78 pixels, and the overly large sun, at 100 times that. Nobody can convince me that we have to succumb to post oil crisis. There is more energy in the wind and (feable) sunlight than thousands of fossil fuel supplies. Just one such is overheating the world (4-D glacial observation). It (poster), is only in cyberspace, as the real, more detailed version, I can't yet afford to produce. The text is availabe online and I want everyone who cares about putting a STOP to global warming to do something to spread awareness. Now may be too soon to actually build a full blown RE infrstucture, though. With rapid advancements like mass produced glass/mirror/CPV, like this, An intire infrastructure could be deemed obsolete! A careful gamble should be enacted upon which is the best timing to actually petition governments throughout the world to make laws to build exponential RE farms. Petition them now instead to fund research to advance the cheapest way to collect RE and tell all!
Re: To prove a point or two...
What is "RE"? Also remember that Global Warming can quickly and cost effectively be stopped by placing a few hundred hectares of Iranian and Syrian soil into the upper atmosphere, The increase in global radioactivity would be less per year than one visit to a therapeutic radon cave.
Re: To prove a point or two...
Boy, am I late...
"RE" is renewable energy and I never thought there was a better way to make a global sunshade than by use of the same billion or so mirrors that would generate RE juice... I hear they (OPEC) are going to buy us out...
...in encouraging any new technology should be by providing enough financial incentive (whether it be through direct participation or tax relief...) to cause industry and individuals alike enough empetus to purchase and use the technology. While we may decry our current administration's position on the environment, please consider for a moment that in the case of PV installations, this administration has done something that no other has: 1) removed any potential ceiling or cap, and 2) guaranteed a 30% participation of the RETAIL cost of the project. When married to RE quota requirements imposed by states on utilities (and resulting in additional incentives from those sources...) PV installations are now not only socially viable, but are fast approaching economic viability as well.
Guest (liftedresearch0)
I am enthusiastic about the possibility of the economic feasibly of solar energy not just on a large commercial scale but also for individuals who wish to reduce their dependence ot the evil electricity monopolies. More importantly, I wonder if any of you brilliant tech savvy individuals know of new programs in Europe that provide incentives and tax breaks for use of Solar energies. I realize already that there are a number of programs in place especially in Germany, France and Spain however, this process is ongoing and I’m unaware of new policy. If anybody knows of a website that gives updates on alternative energy programs both in the U.S. and worldwide I’d be forever grateful
Thanks,
Nick
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Guest (kitk)
is this real?
if this is for real, it is perhaps the biggest quantum jump in solar power in years! but how do you keep the cells from burning, or melting, with such an increase in light intensity? and how long can they live, with such wide swings of temperature as from strong sun at a 500 fold increase to a cold night? but if this does work, it is a new world.
Reply
Guest (gc)
too hot?
We selected 500 suns as the optimal between cost-peerformance-reliability and passive cooling. In fact, the cells only heat to 25C over ambient. As the are type III/V, with Ge as substrate, they lose just 3% overall efficiency at 100C, which we should never reach. As to surviuveability, similiar cells used in LumiLEDS, can tolerate junction temperatures of 185C. As to thermal shock, the mass of the solid dielectric prevents rapid transients.
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Guest (gc)
Focus!
sorry for the numerous typos!
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smuie
1 Comment
Re: is this real? sort of
hardly a breakthrough. Boeing has been building the GAs chips for decades for sattelites. Mnay business cases to concentrate were snuffed by investors...until venyure funds declared energy a new technology. Solfocus is merely buying Boeing Spectralab chips and putting them in a small concentrator. $4/watt is hardly compelling.
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