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Optical Concentrator To Make Solar Power Cheaper
Al writes "Researchers at a company called Morgan Solar have developed a simple solar concentrator that promises to cut the cost of solar energy. The Light-Guide Solar Optic (LSO) consists of a specially-molded acrylic optic that traps light and guides it toward its center using total internal reflection. At the middle of the concentrator another optic made of glass receives the incoming light, amplifies it and directs it toward a small solar cell at the very center of the device. Unlike other concentrators, the light doesn't leave the optic before striking a solar cell so there's no air gap, and there's no chance of fragile components being knocked out of alignment. This could significantly reduce the cost of manufacturing this type of solar cell."
That's actually pretty cool. By concentrating the light, they need less photovoltaic material per square foot of land used for solar. I'm curious how the efficiency of photovoltaic cells varies with the concentration of light. Will 1 square foot of sunlight concentrated into a few square inches of photovoltaic cells produce as much power as 1 square foot of unconcentrated photovoltaic cells?
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Haven't they been using things like this for decades? Sure, it works, but I don't think it's an original concept, is it?
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Neat idea, but how do they get rid of the heat of 1000 suns? Does the IR escape because it isn't reflected the same way?
This would be great for smaller devices, like mobile handsets because there would be smaller surface area required. I like the idea of walking around with an iPhone for a few days without having to charge it if I'm not near a PC or laptop.
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From the picture, it looks a lot like a fresnel lens.
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... about concentrating solar power.
now we need to go OSS in diesel cars
Watch out for the man with the golden gun...
It concentrates the light, increasing the intensity over a smaller area. I don't see where amplification (creating more light) is involved at all.
And when at last it is time for the transition from megacorporation to planetary government, from entrepreneur to emperor, it is then that the true genius of our strategy shall become apparent, for energy is the lifeblood of this society and when the chips are down he who controls the energy supply controls Planet. In former times the energy monopoly was called "The Power Company"; we intend to give this name an entirely new meaning.
* CEO Nwabudike Morgan "The Centauri Monopoly"
well, does it?
btw, btdt. i believe the name, Ames, is attached to the prior art. it was never commercialised because it was "too hard" to produce at the time.
Does this thing have to be aimed at the sun? In 1D or 2D? If it needs 2 pointing axes, it's too complex. 1D, maybe; there are trough-like concentrators at Mojave which are driven to move with the sun.
My house has an nearly unbeatable infestation of small ants, and I can't help but think just what a magnificent burning lens one of these would make minus the solar chip.
But aside from that, there are some other pretty nifty uses for concentrated sunlight. I am definitely curious whether the lens can be scaled up to a square meter or more, enough to possibly melt glass or aluminum.
I live in LA. To the east of us is the Mojave Desert, and there's already quite a bit of solar power out there right now. The big issue is transmission lines to get the energy from the Mojave to LA. Building transmission lines requires political action, and that's slow and uncertain because of NIMBY. I have photovoltaics on my roof, but objectively, if you look at the price of land where I live versus the price of land in the Mojave Desert, it's pretty clear where you should be building these things.
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This should arrive just in time to recharge my flying car. I can hardly wait!
I am definitely curious whether the lens can be scaled up to a square
You're thinking of solar furnaces, like the one in Odeillo http://en.wikipedia.org/wiki/Solar_furnace (already in production for over 20 years ...)
Yes, I'm left. You have a problem with that?
It's TFA's fault, but even so.
There is no "amplification" taking place at all, merely concentration. Those are two VERY different things.
Neat idea, but how do they get rid of the heat of 1000 suns? Does the IR escape because it isn't reflected the same way?
About 80% of the energy is absorbed across the entire solar spectrum. Yes, it will radiate some heat away as IR, but mostly the heat is convected away by the surrounded air. You're right, though--this is a design concern for these devices, as temperature effects efficiency and lifetime.
"I zero-index my hamsters" - Willtor (147206)
They keep them in the dark so they don't get hot.
or from wikipedia:
The solar cells require high-capacity heat sinks to prevent thermal destruction and to manage temperature related performance losses...In May 2008, IBM demonstrated a prototype CPV using computer chip cooling techniques to achieve an energy density of 2300 suns.
of this particular solar advance means not only greater efficiency and lower cost, but also MUCH MUCH greater feasability for wider adoption by areas of higher latitudes. In addition, this particular advance would appear to reduce the detriment of partial occlusion by some factor.
This concentrator technology also reduces the manufacturing use of rare metals for these systems and that is another huge benefit also.
Game: Player 'Donald J Trump' now has AI skill level 'experimental'.
That's the thing about alternatives. Storage. Also unlike wind solar panels block the ground underneath big time. One has to wonder about the effect if solar becomes a bigger source.
Shai Schticks:"You don't make peace with friends, you make peace with enemies"
Amplifying light with a glass 'optic' would be quite original. Concentrating it yes, but amplifying it?
I would be very impressed if they have actually achieved it.
> optic made of glass receives the incoming light, amplifies it
I'm sorry, but an "optic made of glass" can not amplify light. All it can do is concentrate it.
In fact the whole this just sounds like packaging a solar cell and an elaborate magnifying glass to me.
No net decrease in surface area. No proven increase in efficiency.
Sig Battery depleted. Reverting to safe mode.
If this material concentrates all of the sunlight onto the PV chip in the center does that mean that NO OTHER light will pass through it? From the description of something that will take (sun)light from any angle and direct it towards the center does that mean someone behind it will only see black?
If not, it might be a good surface to use on the millions and millions of square feet of windows that covers office buildings. You could conceivably generate ALL of a buildings energy needs that way. (The power generated would also be in good correlation with needs, hot day requiring air conditioning would often come with bright sunlight). Admittedly, the fresnel (like) lens might distort the view so much that you can't see anything recognizable outside but having a translucent like screen to the outside could be a lot less claustrophobic than a blank wall.
Interesting to compare this to a holographic concentrator. This optical concentrator has a much higher concentration ratio and thus allows the use of much less silicon, but on the other hand it requires a mechanical tracker and a heat sink, which the holographic concentrator does not.
I hope to see both these technologies in production soon. $/W is the big barrier for photovoltaics.
Your god may be dead, but mine aren't!
There has been so many news about breakthrough in power cells technology... making them cheaper and more efficient... but why the hell are they still so damned expensive?
My first thought was, why are they using a PV cell in the first place, instead of using the heat to drive a turbine?
In other words, a Fresnel lens. Nice!
Didn't Joe DuBois invent this on Medium last season?
Sounds like sugar ants... your exterminator will have ample methods of dealing with those, or read up on it yourself:
http://www.google.com/search?hl=en&q=sugar%20ants&btnI=I'm+Feeling+Lucky&aq=f&oq=
The sugar ants here are real suckers for the bait, it works like magic.
At some point, they'll come up with a good system that uses PV cells to collect light and use the excess thermal energy to drive a turbine.
if you increase the "efficiency" by 3% while doubling the size, is that really "more efficient"? Isn't that just collecting more photons?
Or use the waste heat to drive a stirling engine as a booster perhaps. I know just regular solar panels get wicked hot on the backs of them when sitting in full direct sun, I mean it is black stuff sitting behind a clear surface and stuck on a metal backing, it gets *hot*. Just doubling that heat would turn it into some sort of decent viable optional energy source.
And why PV? Instant electricity from it, solid state, no moving parts, pretty spiffy stuff. Big solar concentrators with turbines are cool too, we have those for giant megawatt scale production now, but we don't have them for joe homeowner yet or joe back packer, PV fits the bill for those purposes.
Neat idea, but how do they get rid of the heat of 1000 suns? Does the IR escape because it isn't reflected the same way?
I would throw out the idea of a "Tri-brid" power solution.
1) Solar arrays using a design like the article.
2) Steam plant, using the heat byproduct of the arrays.
3) Wind turbines, married to the distribution system with the first two.
My thoughts on this were concerning the land use efficiency. The Southwest U.S. is ideal for all three in many areas. By co-locating and combining the technologies, you get a near 100% output cycle, assuming you don't get the magic trifecta of no sun, no wind, and insufficient IR through clouds to kill any heat input to the steam system on a regular basis.
Design and unit placement would be critical to success, but this is easily doable. Plus you upgrade as needed without losing all of the output during conversion to newer turbine blades or even more efficient PV cells, optics, and so on.
I sent this to T. Boone Pickens' wind power site, urging them to consider high-efficiency solar arrays at the wind turbine installations, where feasible. I've since thought about the waste heat component on the solar arrays, and now think some design consideration should be done about adding that to squeeze out some more juice.
I'd truly like the folks here to blast holes and/or offer suggestions to improve, augment, or modify a CETOS (Combined Energy Technology Output System) like I've described.
Feel free to rename it as well!
So, that's a REAL long answer to what to do with the heat!
I am my own gestalt.
This is dependent on unobstructed sunlight and a properly aligned receptor. Which means tracking systems, which add cost. Perhaps at some point thin film PV will simply become cheaper than the lens system, because although a bigger total area will be needed, tracking will be a lot simpler or unnecessary.
From scarped cliff or quarried stone she cries "A thousand types are gone, I care for nothing, no not one."
or a stirling engine.
These comments are my personal opinions and do not necessarily reflect the opinions of the other voices in my head.
A flat panel can be pointed at the position of the midday sun, and left stationary would have a reduced aperture to the sun as a result of the angle in the morning and evening. Turning the whole assembly helps. But, if there are many panels, they would have to be spread out or else some will shadow parts of others. Basically, it comes down to capture area. If you have a 10 meter by 10 meter area, there's only so much sun that enters it. In the morning and evening, there is less sun entering that area because of the angle. If you have one giant 10m by 10m panel that in there that gets tilted, its shadow will be outside the area, and you're actually capturing sun that would go outside. If you are have lots of small 100cm x 100cm panels, tilting them doesn't help because of the shadows. Remember, there's less total sunlight to get at an angle. Tilting is only an advantage when you have less than 100% coverage, and are willing to lose sun at midday.
Tilting is also a mechanical thing which means some kind of control mechanism, more exposure to failure, and greater maintenance costs.
An optical structure that would funnel light from any angle over a reasonably wide angle range would be the ideal solution. It would handle the change from morning to midday to evening, and would handle the diffuse light of cloudy weather. That's the thing to work on.
now we need to go OSS in diesel cars
Heat water with the waste heat.
When the water tank gets too hot you heat the house with it (or dump the heat outside).
I'd use an oil loop between the collectors and an over-sized water tank.
John McAfee 'It was like that time I hired that Bangkok prostitute; to do my taxes, while I fucked my accountant'
If it effected efficiency and lifetime, the situation would be pretty positive.
What you mean is that it affects efficiency and lifetime.
2) Steam plant, using the heat byproduct of the arrays.
The efficiency of heat engines is governed by the temperature difference between the hot and cold side. Coal and nuclear plants typically have a hot side at around 600 degrees Celsius and newer designs are pushing that higher for greater efficiency. Common glass stats to soften at around 550 degrees Celsius and solar cells start to lose efficiency even at 50C.
The solar array and concentrator would have to maintain a temperature well below 600C just to avoid melting, so any heat engine run from their waste heat would be inefficient.
This is, of course, just the same problem solar has had all along: It's just not efficient enough to compete with other power sources. Coupling inefficient heat engines to inefficient solar arrays only increases the extracted-energy density of the land, not efficiency.
By co-locating and combining the technologies, you get a near 100% output cycle, assuming you don't get the magic trifecta of no sun, no wind, and insufficient IR through clouds to kill any heat input to the steam system on a regular basis.
That trifecta would only require no wind and nightfall, so it would probably happen quite a lot. The low energy density of the IR radiating from the upper atmosphere makes collecting it inefficient. Coupling widnfarms to even out production also has the problem of transmission loss.
Wind, solar, geothermal and hydro are all good supplements where they work, but there's really no substitute for traditional power plants. There are really only two choices for power production today: coal and nuclear. It's either one or the other.
you can already buy big huge fresnel lenses cheap and then use an array of them to do all kinds of solar concentration.
"You're right," Fisheye says. "I should have set it on 'whip' or 'chop.'"
The plastic is the problem. Can't we do it with all glass? If you use a solar furnace you can make it with solar energy. Alternately, if you get enough PV, you can run an electric furnace. Either way, plastic is nasty and sand is everywhere. (Some of the additives in glass are nasty, to be fair. But not all glass is nasty. All plastic is either nasty or has a short life when exposed to UV. Much is nasty AND has a short life.
"You're right," Fisheye says. "I should have set it on 'whip' or 'chop.'"
For a simple lens...
---- Booth was a patriot ----
I saw a system recently which massively concentrates sunlight onto high efficiency PV cells, which are actively cooled, I think by a mixture of gas and liquid coolant. In other words they are cooled like any other type of engine.
http://michaelsmith.id.au
In the places where you would install a solar power plant hot water is probably not a rare commodity.
http://michaelsmith.id.au
Well, if this outfit truly manages to achieve that one dollar per watt figure, it will cause something of a revolution in solar applications. Furthermore, if they can do a buck a watt, odds are that with increased production they can do much, much better.
If an investment of ten grand can buy me ten kW's worth of solar panels (not counting ancillary physical plant and energy storage) I'd consider putting up a small solar farm. Hell, forget the storage system: just buy a synchronized inverter and feed it back into the grid. Let the power company buy it from you.
The higher the technology, the sharper that two-edged sword.
I have a $9.99 solar powered battery charger from Crappy Tire that charges 4 NiMH AA's in about 3 days. It has a little watt meter thingamajig on it that shows watts or rather, the amount of energy being pushed back into the batteries. It takes about 3 days to charge them.
By using a couple of bits of broken mirrors on either side of this gizmo, increasing the amount of light hitting the solar cell, the needle on the watt-o-meter is pegged and the batteries charge in one day instead of three.
So no, the idea of concentrating light to improve the efficacy of solar cells isn't new, just this way of packaging them is. And it's clever.
Need Mercedes parts ?
" Neat idea, but how do they get rid of the heat of 1000 suns? Does the IR escape because it isn't reflected the same way?"
(Looks outside at the grim February bleakness laughingly referred to as "winter")
I can not answer your question. But as a Canadian I have some suggestions as to where you might send some extra heat.
Need Mercedes parts ?
Yes, we need a way to get rid of all that heat. After all, heat is the last thing we need when generating electricity; just look at any typical conventional electric generator plant .
Acrylic rapidly becomes yellowed when exposed to ultraviolet, and especially under very high-intensity light, even if it has anti-yellowing chemicals added. This article, Applications and Limits of Polycarbonate and Acrylic Lenses, explains "... yellowing is a sign of degradation of the plastic molecule. Heat and ultraviolet act to break the molecules. This surrenders the intrinsic strength of the material as the molecular structure no longer consists of long intertwined chains but fractured segments. This may be reflected in reduced strength of parts with formed surfaces as these surfaces tend to localize stresses."
The article, A Cheaper Solar Concentrator, referenced in the Slashdot story says, "With a flat bottom and convex, mirrored top, the [Morgan Solar] optic receives the incoming barrage of light at a concentration of about 50 suns and amplifies it to nearly 1,000 suns before bending the light through a 90-degree angle."
The article does not explain how there is a concentration of 50 times before the light reaches the optics. The article is wrong in using the word "amplifies". The correct word would be "concentrates".
To have a 1,000 times concentration, the area of the optics must be 1,000 times larger than the area of the solar cell. That delivers 1,000 times the heat, also.
Morgan Solar's investors page says, "Morgan Solar was incorporated in June 2007 and is currently well funded by a start-up investment from our angel investor and Chairman, Eric Morgan." Apparently the company was funded by the inventor or someone in his family. It says, "Our plans call for securing our next round of investment funding by Q1 2009. If you are a venture capital company or a potential partner-investor interested in exploring investment opportunities with our company, please contact us."
Was a Slashdot editor paid to allow this story? Did Slashdot profit? Was Technology Review paid to run the story? I think that articles about companies that are soliciting investments should have a statement about whether or not someone was paid.
I'm fully aware about how PV degrades with temperature rise, I own some solar PV and use it (since 99 actually), I just noticed a long time ago the backs get really hot. I haven't done it yet but I think you might be able to integrate a built in fluid radiator to the backs of them and remove heat that way and use it for hot water or additional space heating perhaps. Or something, that's the thing, you are gathering it, it is waste, it needs to be removed, so why not figure out what useful purpose it could be put to? Maybe as a preheater to a solar still, to make the distilled water for the battery bank? I don't know, but *something* can be done with it. As soon as I have the scratch for a "spare" one I wanted to try some experimentation on it, as it is now I don't want to chance destroying a multi hundred dollar PV panel, and I don't want to experiment on some cheap little bitty hardly useful one, I want something that is actually worthwhile to use and would give me real world results.
Just another one of those projects for the future, add it to the list.....heh, ya never run out of projects!
There's a system being deployed in Australia called Combined Heat And Power (CHAPS), that uses curved mirrors to focus the sun onto what is essentially a pipe covered in photovoltaic cells. The PVs convert some of the energy into electricity and are cooled by water flowing thru the pipe, which then feeds the hot-water system of the building they're mounted on. Total claimed efficiency is up to 60%. The system is currently installed ont he roof of one wing of Bruce Hall, a residential college at the ANU.
Linkies:
http://solar.anu.edu.au/projects/chaps_proj.php
http://abc-webdesign.com.au/examples/solar/pages/chaps.html
sustainable living
Well, if you attach your solar cell to a heat sink the same size as the concentrating surface (lens), then you have as much area to dissipate heat over as you have for a normal, non-concentrating panel.
In other words, the ratio of light collecting area to heat emitting area is the same in both cases.
Isn't heat a form of energy? There must be a way to convert it to electricity.
Optical concentration for solar cells using lenses or mirrors is of course old news. They work dandy except for the problem that the more you concentrate the more you have to track the sun's position. Tracking solar cells are an economic non-started except in certain applications.
Now classical optics says you cannot compress phase space with refractive or reflective optics. Ergo the claim being made is impossible unless they are
1) relying on non-refractive optics (e.g. scattering)
2) only gettin a boost no larger than the index of refraction of the material (i.e. immersion lenses can concetrate by a factor equal to the index of refraction as long as the absorption occurs inside the medium.
otherwise this is just back to tracking and thus useless.
Some drink at the fountain of knowledge. Others just gargle.
My house has an nearly unbeatable infestation of small ants
I got rid of a nasty colony of Pharoah ants with the Terro sugar/boric acid liquid bait, drizzled on the outside walls, they came and ate in droves and just vanished within a week.
Or, you could just demolish the structure and burn it, but I bet the ants would actually survive that and just move away.
Neat idea, but how do they get rid of the heat of 1000 suns? Does the IR escape because it isn't reflected the same way?
No problemo. Once it hits 6000 Kelvin, it will be in equlibrium with the sub blackbody and not get any hotter.
Some drink at the fountain of knowledge. Others just gargle.
With the weekly, and sometimes daily, promises for cheaper solar panels, when am I going to be able put them all over my roof for less than $10,000? $1,000?
There are multiple ways. One way is with a thermoelectric generator that utilizes the Seebeck effect. There are numerous other heat engines available to carry out the process.
Or you could get hot water as a side benefit of the need to cool the solar cells.
"Is life so dear, or peace so sweet, as to be purchased at the price of chains and slavery?" - Patrick Henry
Stirling engines will never be economical.
Engineering Ratholes.pdf
"there is a key component to a Stirling engine that nobody - but
nobody - has figured out how to build yet. It is called a
regenerator. Any regenerator has to be long and thin and
short and fat. Not to mention being an excellent insulator
and a superb conductor." -Don Lancaster
Also see www.tinaja.com/glib/hack64.pdf for a review of the dismal Carnot efficiency of modest temperature drops.
You can get hot water from cooling PVs, but running heat engines is impractical unless they're really, really cheap.
"Is life so dear, or peace so sweet, as to be purchased at the price of chains and slavery?" - Patrick Henry
Or you could boil water and run it through a turbine and get more electricity!!!!!
Occam's razor is the blind faith in the natural selection of least resistance and in universal oversimplification. -- EF
Stirling engines will never be economical.
[snip]
Also see www.tinaja.com/glib/hack64.pdf for a review of the dismal Carnot efficiency of modest temperature drops.
It's pretty well understood that you need a big temperature drop. That's why they don't use a small temperature drop. If it doesn't work then what are these people doing?
Frankly, solar thermal makes more sense to me (see Nevada Solar One, or the Solel project), but sterling engines work too.
The more people I meet, the better I like my dog.
When did "optic" become a noun?
P.S. Why are you still on my lawn?
Most houses use hot water.
Try bathing some time.
It's not as bad as you remember it.
John McAfee 'It was like that time I hired that Bangkok prostitute; to do my taxes, while I fucked my accountant'
Wow - This is straight from Medium! Allison DuBoise's husband invents just this very thing for the middle daughter's science project.
If it doesn't work then what are these people doing?
Losing money.
http://www.usatoday.com/money/industries/energy/environment/2008-01-20-solar-power_N.htm (worth reading)
"Osborn agrees cost is Stirling's biggest technical challenge. Each hand-built test dish cost $225,000. That needs to drop to less than $50,000, Osborn says."
Let's say that this is a 40ft. diameter dish in 6kWh/m^2 per day, 365 days per year territory with a thermal efficiency of 25%
that's about 63,000 kWh per year, if I've done my math right, which means $6300 at 10 cents/kWh. I think that's a realistic number. But let's say they get $10,000 a year for the power from one dish. The dishes aren't going to cost $50000, it'll be more. Then they'll need land, permits, environmental studies. Then they need power lines, which can't be bought for any price in California, but even if they could, would add tens of thousands of dollars per dish. Then there will be maintenance - the mirrors need cleaning, the moving parts in the Stirlings will wear out, and unforeseen expenses are inevitable. At the end of the day they simply can't make a return on capital that is attractive. If everything goes perfectly, the projections they make to get investors turn out to be correct, there are no expenses other than their $50,000 projected equipment costs (...hell freezes over, monkeys fly out my butt...)they make 20% return. Given the factors mentioned above, it's more likely that the best case is they net $3000 after maintenance and land on $100,000 investment, which means they don't cover real inflation, let alone the cost of capital.
"Is life so dear, or peace so sweet, as to be purchased at the price of chains and slavery?" - Patrick Henry
Neat idea, but how do they get rid of the heat of 1000 suns? Does the IR escape because it isn't reflected the same way?
From their website describing a (not-yet-available) product (http://www.morgansolar.com/sunsimba-features.php):
The materials use block infrared radiation, preventing it from concentrating at the PV cell.
Heating does occur, however the aluminum spine is cooled by convection which allows hot air to escape up and through air gaps in the solar modules.
Somebody call up the guys in pajamas from the Unseen University...
I know tobacco is bad for you, so I smoke weed with crack.