MIT solar dish holds promise for low-cost energy production

Look out 1366 Technologies, you've got yet another solar-based MIT spin-off company vying for business in the alternative energy sector. The company's name is RawSolar, and in due time it could end up selling solar dish arrangements that could power factories or even heat / cool office buildings. Recently, a team of students and faculty celebrated as a prototype dish proved that it could concentrate sunlight by a factor of 1,000, which obviously bodes well for converting that into useful energy here on Earth. Another standout feature of the dish is its small size, and furthermore, the material required to build it is relatively inexpensive and accessible worldwide. Sounds like all the ingredients for a successful startup are there, now we've just got to wait and see if anything becomes of it. We're watching you, RawSolar -- don't let us down.

[Thanks, Spencer]

[cy21 @ Jun 20th 2008 8:53AM]

promises, promises...
any demo that's going to blow our minds out and show relevant statistics on how they will do as they promise ? no? i thought so....

[Danakin @ Jun 20th 2008 9:36AM]

it's MIT dude, those geniuses are always doing cool stuff and coming up with ideas...it doesn't matter if they demo what they can do to the public, it only matters if it works and they can get the funding to build more...the masses don't matter until they get to selling them.

[OneLove @ Jun 20th 2008 10:53AM]

dude you look like a skin head.

[lawyer bird @ Jun 20th 2008 12:17PM]

serial killer

[Murphy Mac @ Jun 20th 2008 8:57AM]

what's the dude in the picture doing?

[cy21 @ Jun 20th 2008 9:03AM]

he's holding up a very big piece of wood

[natels @ Jun 20th 2008 9:05AM]

He's clearly lighting a big stick on fire to show the practical use of such an invention.

[Don Corleone @ Jun 20th 2008 9:03AM]

This is a giant solar powered cigarette lighter!

So if these things can concentrate power, why don't they aim them at solar panels?

[Mage @ Jun 20th 2008 9:21AM]

Because it would burn a hole through it. This type of solar concentrator is normally used in conjuction with a water/steam generating system. Though I have not seen one small enough that would work with this. However I am sure that is what they would be working on.

[earthling @ Jun 20th 2008 9:17AM]

@Don Corleone

Silicon and heat don't mix all that well. Solar Collectors are used sometimes to make the concentration of a specific wavelength of light more efficient, or to just increase the amount of light avaialble, but a design like this one is probably aimed at generating heat. Heat = energy, energy = power. By superheating something like water you can make steam and use the steam to drive a generator. (for instance).. Or heat a pool, or your office, or the backside of your jeans (remember the magnifying glass prank from grade school)..

[Uejjji @ Jun 20th 2008 9:28AM]

Do you want a burning solar panel?

[Eric @ Jun 20th 2008 9:18AM]

Because the heat generated would reduce the output, and it is likely if you can burn a 2X4, you would destroy the panels.

However, a lot of people are using small lenses on solar panels to get a slightly higher output.

[Jonathan @ Jun 20th 2008 9:27AM]

Let's just say that you wouldn't damage the PV panels you were pointing at...

The efficiency of PV will drop about half a percent (from posted STC rating) for every °C over 25°C.

[dj-kenpo @ Jun 20th 2008 9:13AM]

sell it in kit form or DIY!

too much stuff never gets released... it's the only way any of this is going to get off the ground before 15 years from now

[Ed Hearne @ Jun 20th 2008 9:16AM]

This strikes me as a very bad idea. I imagine any unfortunate bird would be fried instantly should the accidentally fly over one of these things. Not to mention the abundance of "Darwin award" winners should these things ever get out in public. I can already see the headline "Man incinerated while trying to clear dirt off his solar dish".

[Dinosaurus @ Jun 20th 2008 9:21AM]

I think there are enough birds in this world that the occasional cooked sparrow isn't going to threaten the existence of the species. As far as the Darwin award goes, there are a million and one ways to hurt yourself in this world, doesn't mean we shouldn't have things that might be able to hurt us around.

[lowbot @ Jun 20th 2008 5:18PM]

You could make that comment about all our existing technology: trains, cars, powerlines, etc.Idiots and animals, are for the large part, disposable to society. Always have been.

Not to mention that a solar array is a lot safer than burning coal. If some kid manages to burn his head off once every year then thats a lot better than millions of people eventually getting lung cancer or empheseuma because of pollution.

[srl @ Jun 20th 2008 11:07AM]

Actually for much of the developing world generating heat for cooking is the major problem. I'm sure once their 50" Plasma TVs arrive they will become interested in electricity.

Unlikely to be fried instantly (or even baked instantly) - just as your hand is
not baked instantly if you happen to touch a flame (which has a higher temp than this will generate).

[macserv @ Jun 20th 2008 2:50PM]

So what do you think of wind turbines? THE BIRDS!! THE CHILDREN!!!

[Benson @ Jun 20th 2008 5:35PM]

Awesome; since nobody's pointed out the obvious yet, here's yet another reply...

Well, a bird doesn't have to "fly over", it has to fly THROUGH the volume around the focal point that is intense enough to burn it during a flythrough; so it's sufficiently improbable that it's probably not even worth setting up a webcam for all the more Phoenix footage you'd get in a year...

And when cleaning it, of course... (Did you LOOK at the picture?) The focal point is at least ten feet from the dish; even if you didn't turn it away from the sun to defocus, you'd have to climb that pole in the middle to get out there and get burned; crawling/rolling/whatever around to clean the dish will net you no worse a burn than from laying on your porch in the sun for the same time.

[earthling @ Jun 20th 2008 9:19AM]

Solar collectors/concentrators have been around for many, many years. The innovation here is not the concept, but the manufacturing process and efficiency of light gathered.

You can buy them from catalogs as portable grills, pool heaters, alternative water heaters, magnifying glasses, fresnel lenses, etc, etc,etc,etc,..

[Dinosaurus @ Jun 20th 2008 9:21AM]

I wonder if one of these could heat up a hot water heating system here in the north, the type that runs water tubes through a slab. Heat the water during the day and the slab holds the heat until the next day. My parents have a slab system that runs off of LP and it's about the nicest feeling heat you can get.

[earthling @ Jun 20th 2008 9:36AM]

They are called Thermal Energy Storage solutions or TES. They are used primarily for cooling but conceptually it is similar. You use the off peak power (or free power such as solar) to create energy which is then stored in some container. In cooling systems you literally freeze a large block of typically water and some chemical and then use that block of ice during the day during peak hours to provide cooling. Work is just starting in heating systems but there are examples of this in commercial production as well. BMW had an option in its cars that stored the heat created from the engine in a container filled with I think a brine solution (called a heat battery or heat reservoir) so when you start the car the next day it can warm the interior instantly (or so the plan went)

[kamu @ Jun 21st 2008 2:15AM]

Generally what they do in large scale applications such as Solar One, Two and Tres is melt nitrate salt and store it in tanks, which will last the night.

[strayan @ Jun 20th 2008 9:21AM]

Really not new whatsoever

http://www.environment.gov.au/settlements/renewable/recp/pv/pubs/pv9.pdf

http://www.environment.gov.au/settlements/renewable/recp/pv/images/pv9.gif

[Niallers @ Jun 20th 2008 9:34AM]

I'm glad to see people are still working on death/heat rays!

[Chris @ Jun 20th 2008 9:38AM]

they already have professional companies doing these dishes but their expensive because of the mirrors etc....

my idea would work better and be made for A LOT cheaper...

a properly molded and tuned standard satellite dish..... cover it with laminated 99.9% reflective MYLAR much better than even the best mirrors and 1/1000th the price.

just my 2 cents.

[Iridium @ Jun 20th 2008 9:42AM]

Uh this one looks just like the Archimedes death ray they built on Mythbusters.

[BowserUSC @ Jun 21st 2008 2:55AM]

Well it is the same concept, just a different use of the energy.

[JamesM @ Jun 20th 2008 9:44AM]

This has already been done. If you look at www.cockeyed.com, the site owner did an experiment where he made a dish like this from spare parts

[ma5t3rw1tt @ Jun 20th 2008 9:55AM]

Sweet, now thats one hell of an idea. I would get one for my house if I could afford such a thing. Any way to cut bills and emissions would be someone to be proud about. At least I know I would be doing my part to help fight the cause.

[san_terre @ Jun 20th 2008 10:03AM]

Boring....

http://www.cockeyed.com/incredible/solardish/dish01.shtml

[Josh @ Jun 20th 2008 10:13AM]

I'm glad someone mentioned Rob's "Cockeyed" website.

It looks like Life (MIT) Copies Art yet again.

Aside from the 'prior art' I like the form of the MIT dish, it looks very light and still rigid.

[kevjohn @ Jun 20th 2008 10:24AM]

1000X solar power?!?
Fastest. Steaks. EVER!

[Joe in MD @ Jun 20th 2008 10:25AM]

Just looked for more specifications on how this was done without much luck. I then looked for flexible mirrors and found a couple of sources -- funhouse mirrors and children's mirrors seem to predominate. You can buy 24"X48" mirrors for about $50. It would take only a bit of work to compute a cutting pattern to fit the mirror onto a parabolic frame. With about 4 of these sheets one could have a 4'-square (approximately) mirror without having to wait for some special supplier as they (apparently) did. The downside seems to be that these flexible mirrors are not designed for long-term weather exposure. I suspect some UV coating on the front and some epoxy or other coating on the back would make them last a long (enough) time. Having to replace the surface every few years would not be a huge burden.

Another thought -- how about getting an old satellite dish and gluing small mirrors to it? Already comes with the hardware to position it -- just add a tracking module.

[san_terre @ Jun 20th 2008 12:48PM]

Been there, done that...

http://www.cockeyed.com/incredible/solardish/dish01.shtml

[hC @ Jun 20th 2008 10:39AM]

Francisco Scaramanga would approve.

[lesvoirons @ Jun 20th 2008 10:45AM]

I really don't get it, what is 'revolutionary' here???
The idea is not new and has already been applied 1,000 times (to paraphrase the 1,000 suns).
What would be cool is to produce this / market this for couple of 100's or 1,000's $

[OneLove @ Jun 20th 2008 10:54AM]

This would be hot in the Caribbean (and elsewhere)!

[Scott @ Jun 20th 2008 11:43AM]

UNLV in Las Vegas has had two of these operating for years - they move and track the sun automatically, and generate energy by focusing the sun on a Stirling Cycle engine.

This is old news.

[Steven @ Jun 20th 2008 1:18PM]

I fail to see the novelty of this. The principles of sunlight concentration have been known since antiquity, and low-cost solar cookers have been used since decades, esp. in areas in Africa where wood was becoming dangerously scarce.
I would be much more interested to see how the geniuses at MIT are going to convert this heat into something more usable. They're not going to cook their potatoes on it, are they? The Stirling engine comes to mind if you want to convert heat into motion.
Or they could split water molecules into hydrogen and oxygen.
I'm curious.

[toyotaboy @ Jun 20th 2008 1:45PM]

"All you need is a tracking system and a large spinning mirror and you could vaporize a human target from space."

"Kent's tracking system is gone! How could you build that mirror?!"

[real genius]

[Jon Doe. @ Jun 20th 2008 4:57PM]

Gah. Factor of 1000 eh. Now if we could get solar cells above...what are we at now a days? 25% efficiency?

[Tim @ Jun 22nd 2008 8:55AM]

I fail to see how this is particularly revolutionary. They may have efficiently concentrated the sun's rays, but they seem rather unclear about what they'll do with those rays. The article talks about boiling water into steam, which presumably could be drive a turbine to generate electricity. All of this will result in energy losses.

Such a system would also require quite a lot of water, although hopefuly you could condense most of the steam and run it back into the generator. Nonetheless, it's still an extra resource that may not be readily available in the kinds of places where solar power makes most sense.

Sounds to me like you'd be better off just sticking with normal solar cells if you want electricity. They require less maintainance and resources.

I guess you could use it for your hot water, but I'd guess that it'd actually be less efficient than current systems.

[bobw @ Jun 25th 2008 4:08PM]

The point is that it's cheap to build. The parts are cheap to buy and easy to put together. There is the genius. An unlimited budget can build something fantastic. The hard part is to do it without an unlimited budget.