Guiding light: Morgan Solar’s high-precision optic--part acrylic and part glass--is molded so that light is trapped and bounces toward its center. A secondary glass optic concentrates the light to 1,000 suns and directs it to a tiny, high-efficiency solar cell. The low-profile design promises to reduce the cost of manufacturing and transportation.
Morgan Solar

Energy

A Cheaper Solar Concentrator

A new light-guiding optic combines low cost with high efficiency.

  • Friday, February 20, 2009
  • By Tyler Hamilton

Nicolas Morgan holds up a square piece of clear, molded acrylic about a centimeter thick and shines a penlight directly at its flat surface. A green beam enters the acrylic and bends toward the center of the square. Morgan repeats the process at different points on the surface, and each time, the beam darts toward the center.

The acrylic component--called a Light-Guide Solar Optic (LSO)--is a new type of solar concentrator that could significantly lower the cost of generating electricity from the sun. Unlike existing designs, there's no need for mirrors, complex optics, or chemicals to trap and manipulate the light. "It's pure geometric optics," says Morgan, director of business development at Toronto-based Morgan Solar.

Solar concentrators have emerged in recent years as a way to intensify the amount of sunlight hitting solar cells, which are the most expensive part of solar panels. To make solar power more affordable, engineers have sought to use less solar-cell material by concentrating sunlight onto much smaller spaces.

But this approach has its own challenges. Most concentrators tend to be complex systems that use special lenses, curved mirrors, and other optical components with a "nonzero" focal length. This means that there must be enough distance--an air gap--between the solar cell and the optic to properly focus the light. As a result, concentrator-based systems are usually packaged within bulky enclosures, with enough depth to accommodate the focal length and protect all components during shipping. This means higher material and assembly costs and more expensive shipping.

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A couple of years ago, Nicolas's brother John Paul Morgan came up with the idea of a solid-state solar concentrator system: a flat, thin acrylic optic that traps light and guides it toward its center. Embedded in the center of Morgan Solar's concentrator is a secondary, round optic made of glass. With a flat bottom and convex, mirrored top, the 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.

Unlike other concentrators, the light doesn't leave the optic before striking a solar cell. Instead, a high-efficiency cell about the size of an infant's thumbnail is bonded directly to the center bottom of the glass optic, where it absorbs the downward-bent light. There's no air gap, and there's no chance of fragile components being knocked out of alignment.

"It's all about critically controlling the angles once the light enters the first optic," explains Nicolas Morgan. The design takes advantage of a phenomenon called total internal reflection--the angle at which a beam of light inside an optical material will reflect back into the material rather than escape.


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phoenix

172 Comments

  • 1089 Days Ago
  • 02/20/2009

A Brief History of Solar Power Part 3

[Removed by moderator]

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ian807

1 Comment

  • 1087 Days Ago
  • 02/22/2009

Re: A Brief History of Solar Power Part 3

Anyone can have a PV array?

Yeah, sure. Anyone with 25K to spare. Say, what's it like on your planet?

Seriously. PV is a rich man's indulgence. A way of assuaging their little consciences by pretending to be "greener than thou."

Until the average couple collectively pulling in $70-80K a year can get one, it's just delusion and fantasy. Call me when I can get a unit for under $2K.

Reply

TooMany

125 Comments

  • 1087 Days Ago
  • 02/22/2009

Re: A Brief History of Solar Power Part 3

You have a point about the costs, but that's not a good reason to be rude. It seems to me that we have lost respect for one another if we respond in that tone. No energy engineering revolution can come about without cooperation or without the enthusiam of people with optimism that something can be done.

The article you are responding just might solve that cost problem. Contribute; being cynical is easy.

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phoenix

172 Comments

  • 1086 Days Ago
  • 02/23/2009

Re: A Brief History of Solar Power Part 3

[Removed by moderator]

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Siphon

152 Comments

  • 1080 Days Ago
  • 03/01/2009

Re: A Brief History of Solar Power Part 3

Ian's basic factual problem is that he ignores learning curves. PV has a very good and consistent learning curve. Since PV is growing from a small base, it's easy to subsidize production (ie relatively tiny amount of money compared to revenues in the world of energy generation).

Enough reasons to accellerate development through subsidies, can't we agree?

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flataffect

3 Comments

  • 1083 Days Ago
  • 02/26/2009

Re: A Brief History of Solar Power Part 3

What the deal, Phoenix?  You couldn't get your article published so decided to put it in the comments?

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Brittany Sauser

46 Comments

  • 1079 Days Ago
  • 03/02/2009

Re: A Brief History of Solar Power Part 3

I have removed the postings that were not fit or appropriate for the comment section. Any questions or concerns please contact me--send me a message through the TR community or via email (brittany.sauser@technologyreview.com). Also, please remember to review our "Terms of Use" before posting a comment.

Thanks,
Brittany Sauser

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ultron07

3 Comments

  • 324 Days Ago
  • 03/27/2011

Re: A Brief History of Solar Power Part 3

Let us remember when one has made over $1 billion in 1900 and has successfully resisted anti-trust breakup legislation, successfully manipulated the stock market, avoided the payment of 945,000,000 in income taxes, manipulated the market in 1928, shorted his competition, profited from all wars and banned competitive practices, the poor startup does not do well. The Pentagon drives ALL research for military purposes and deprives the commercial markets and humanity of the benefits, only for the benefits of the few. Flash crashes can destroy all the shareholder's liquidity of ANY company in less than 4 hours. Look around you, above you and below you, and you will see the benefits of the greatest inventor of all time and also remember he died in absolute poverty. MIT is a great school.

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terryshook

1 Comment

  • 539 Days Ago
  • 08/24/2010

cheaper solar concentrator

Brilliant!  Would love to get my hands on one to play with.  i love to experiment with solar on my pool and hot tub.

Keep up the good work.  It is inspiring.

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DWagner

3 Comments

  • 307 Days Ago
  • 04/13/2011

Optics durability

This sounds like an interesting idea, but I believe it would be similar to a grooves out Fresnel Lens.
This may cause difficulty with dust.  I am really eager to see details.  Different optics have been used in other concentrators.  Look at www.Sol-Solution.net for a description of a Rainbow Concentrator which separates and concentrates the sunlight with one cheap lens.

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DWagner

3 Comments

  • 307 Days Ago
  • 04/13/2011

Patent application for this


Application number: 12/554,481
Publication number: US 2010/0126554 A1
Filing date: Sep 4, 2009

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