From 40.7 to 42.8 % Solar Cell Efficiency

[jpak]

http://www.renewableaccess.com/rea/news/story?id=49483

Using a novel technology that adds multiple innovations to a very high-performance crystalline silicon solar cell platform, a consortium led by the University of Delaware (UD) has achieved a record-breaking combined solar cell efficiency of 42.8 percent. The current record of 40.7 percent was attained in December 2006 by Boeing's Spectrolab, Inc.

The research was led by Allen Barnett, principal investigator and UD professor of electrical and computer engineering, and Christiana Honsberg, co-principal investigator and associate professor of electrical and computer engineering. The two direct the University's High Performance Solar Power Program and have been working to achieve the 50 percent efficiency goal set by the Defense Advanced Research Projects Agency (DARPA).

Barnett and Honsberg said that reaching the 42.8 percent mark is a significant advance in solar cell efficiency, particularly given the unique small and portable architecture being used by the consortium and the short time—21 months—in which it was developed.

Honsberg said the previous best of 40.7 percent efficiency was achieved with a high concentration device that requires sophisticated tracking optics and features a concentrating lens the size of a table and more than 30 centimeters, or about 1 foot, thick. The UD consortium's devices are potentially far thinner at less than 1 centimeter.

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[Trillo]

1. Are the developers concerning themselves too much with 'perfection'?

When scientists finally attain the 'perfect' solar cell, how are poor people going to afford them? Regardless of cost, where will the royalty money go? To one particular consortium that finally developed the perfect solar cell?

I keep marveling at these advances through the years, but I still keep remembering the university professor on the TV science show back in the late 70s that claimed the new (at that time) laser manufacturing process meant solar cells could be made for pennies per square foot.

The corporatist with its distribution network never allowed that technological advance to retail to folks with a reasonable markup, only an unreasonable one.

I guess it's wonderful that there are grants for a few folks to keep perfecting these unaffordable energy devices. Nice jobs program!

[gravity]

2. Cost is a more important factor than effeciency

These ultra effecient solar cells are probably aren't going to be economical except for some niche applications.

Most solar companies right now are more concerned about getting the best price per kilowatt compared to overrall effeciency. Effeciency plays a part in this especially when space for the cells becomes limited, but it all really comes down to the bottom line.

[skids]

4. Actually these cells are important for cost reduction...

...in areas with low cloud cover.

The cells in this series have been selling for $10 per square centimeter (not the 42.8% efficient ones but the ones in the high 30s), and take 200 to 300 suns worth of illumination (some of them up in the 500s and 600s.) So you multiply that 1 square centimeter out to 200 square centimeters, and come up with 1/50th of a square meter. A square meter gets 1000 watts from direct sun, so divide that by 50, and you see that you can shine 20 watts worth of power onto these babies. 40% of that is 8 watts of usable power.

So that $10 per 8 watts, or $1.25 per peak watt.

Si panels cost $4 and change per peak watt. Thin film (the best alternative for cloudy areas) panels cost $3.50ish per watt.

So the final cost all depends on how much the concentrator costs, but the cost of the cell is less than half that of the other technologies, and likely produces a lot less waste.



However, you can also concentrate 3 to ten suns onto some of the less efficient panels. The question is which will end up being less expensive -- low concentration onto cheap cells, or high concentration onto premium cells? There are close to a hundred companies all with their designs at various stages -- only a handful actually shipping product at present, but things should be getting much more interesting much more quickly.

[Dogmudgeon]

6. I'm lost on some of that

What is a "sun" in the context you are using it? Light intensity?

Even 100 times the intensity of the sun would cause some serious heating to an exposed surface. This is desirable in solar thermal energy use, but not with semiconductors.

Perhaps I am missing something here. Can you provide a little background?

--p!

[skids]

8. Yep you got it...

These semiconductors are designed for high heat (100C) and actively cooled. Actually single cell systems can get away with passive cooling. In some cases (not in Si cells) the heat actually helps improve the cell efficiency by knocking loose electrons. At the extreme, there's also thermophotovoltaics which operate at some pretty unbelievable temperatures.

http://www.energyinnovations.com/technology/

http://lees.mit.edu/lees/projects/thermophotovoltaics_project.htm

http://www.spectrolab.com/prd/terres/FAQ_terrestrial.htm

[NNadir]

3. Another "innovation" and "breakthrough?"

Man over the years, you've reported breakthrough after breakthrough, a brazillion of them...

Brazillions of megawatts...

Brazillions of roofs...

You still can't report one exajoule though...

You would think that solar wouldn't need so many "breakthroughs." I mean it's the bestest mostest goodest superiorist form of energy there is, no?

Why it the mostest Maine Solar Housest in Maine, no?

How about producing a brazillion links about a brazillion installations? I love it when you do that.

Oh look, 10 kilowatts!!!!!!!:




I was at this particular bestest mostest goodest solarest facility ( http://www.njng.com/conservation/renewableEnergy.asp)

It was producing 4,000 kw, not 10,000 according to the display.

Here's a picture of all the people who came to "dedicate" it.



I wonder how much gasoline all these people burned to come dedicate their new solar facility.

I'll bet that all these people don't come for the dedication of a new substation...

[Bread and Circus]

5. Are you an idiot?

just askin' :shrug:

[Systematic Chaos]

7. No, but he did stay at a Holiday Inn Express with a solar pool heater last night.

:eyes:

[Kolesar]

9. That article does not explain the magnifying technology very well

"By integrating the optical design with the solar cell design, we have entered previously unoccupied design space leading to a new paradigm about how to make solar cells, how to use them, and what they can do."