Spectrolab claims record efficiency for new solar cell
Spectrolab has achieved a record 37.8 percent efficiency with a new multi-junction solar cell (not pictured) (Photo: Shutterstock)
Spectrolab, a Boeing subsidiary known for the manufacture of solar cells for satellites and spacecraft, has in recent years turned its attention to terrestrial solar cells to tap into the expanding alternative energy market. Now the California-based company has claimed a new solar cell efficiency record of 37.8 percent for a ground-based multi-junction cell without solar concentration.
While Spectrolab and others have achieved higher efficiencies with multi-junction solar cells, these were done using sunlight concentrated by lenses or mirrors onto the solar cells. The company says it was able to set a new record without concentration using a new class of high-efficiency multi-junction solar cell.
Unlike traditional silicon solar cells, multi-junction solar cells contain several different semiconductor materials. The interfaces between these different materials – which are known as p-n junctions – are tuned to different wavelengths of light to increase efficiency.
It hasn't been revealed which materials were used in this case, with the news release stating only that the 37.8 percent conversion was achieved "using a new class of high-efficiency multi-junction solar cell, created from two or more materials and leveraging Boeing technology that makes semiconductor materials more reliable."
The company doesn’t intend to rest on its laurels, with Spectrolab’s vice president for advanced technology, Nasser Karam saying the company’s technology has the potential for efficiencies of more than 45 percent, even under lower concentrations.
About the Author
Darren's love of technology started in primary school with a Nintendo Game & Watch Donkey Kong (still functioning) and a Commodore VIC 20 computer (not still functioning). In high school he upgraded to a 286 PC, and he's been following Moore's law ever since. This love of technology continued through a number of university courses and crappy jobs until 2008, when his interests found a home at Gizmag.
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Great! But, at what price per square foot ? And what are the relative toxicities of the components or production techniques? How quickly can this be implemented and scaled up? While Boeing is a company with an obviously legendary track record there are technology choices that were great lab toys but that just did not quite make it as products. Multi-junction cells with liquid cooling to both improve the front surface efficiency while extracting useful amounts of useable heat that can be stored or used as process heat should get us to 60 or 70% plus gain but the key question is still at what price per square foot?
Now were starting to get somewhere.
A high quality thermal collector barely achieves 70% eff so I doubt a hybrid PV plus thermal collector could match that overall eff. After your 38% of electricity, you'd be getting less than 32% of thermal at very best.
Generally a joule of electrical energy is considered about 2x as useful as a joule of high grade heat.
You'd be combining a relatively super efficient PV making valuable electricity with an inefficient thermal collector of low grade and dispersed thermal energy that would have limited thermal use.
As for storing heat, you really need the heat to be high grade for storage to be economical.
This is pretty impressive. I have 60 watt solar panels that are about the size of a coffee table (about 0.5m²).
I think sunlight is about 1 KW/m² (@100% efficiency) from memory and if so a square meter of this new material would produce 378 watts which is about 3 times what my panels produce.
there are solar cell in the lab and then there are solar cells that are marketable. how long do these last, is my question.
frogola makes a good point.
What I want to see is a ranking of all existing solar panels on the market with a weighting of efficiency weighted against cost and tolerances to temperature extremes, to expected lifetime before output drops below 80% of factory.
ie - solar panels suffer as temperatures increase, rapidly aging them, causing reduced output.
@ warren52nz the rating given on most panels is under 1kW/m^2 irradience at a temperature of 25 degrees Celsius. The temperature is important as most cells have a derating factor of about .05% per degree increase
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