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venerdì 20 maggio 2011

By 2015, we could see a new generation of photovoltaic technologies, including 3D solar cells


Solar photovoltaics (PV) is one of the hottest high-tech areas around.
For instance, 3-D technology is all the rage these days.  Now, one company thinks it can bring the concept to solar too.
Santa Barbara-based Solar3D is working on a silicon “microcell” at the nano scale that uses an optical element to direct sunlight into a walled-in structure, thus capturing more photons and increasing the amount of electrons that are discharged. If a traditional solar cell is the ceiling of a room, the 3-D solar cell would be the room itself with the optical element acting as a skylight.
Jim Nelson, the CEO of Solar3D, says the cell could theoretically be 25% efficient. (A traditional silicon-based cell is usually in the 12-15% efficiency range, meaning that 12-15% of the sunlight hitting the cell will be turned into electricity. High efficiency cells are now reaching above 19%, with record cells hitting over 24% in the lab.)
But let’s acknowledge the key word here for the 3-D solar technology: “theoretically.”
Although Solar3D says it is ahead of schedule in development of its cell, it won’t be done with its working prototype until later this year. And it won’t be until 2012 when the company actually plans to ramp up production – assuming its prototype works as expected.

Nelson, who stopped by our office this week to chat with Climate Progress about the company, is a firm believer that next-generation technologies are the key to scaling solar photovoltaics. He doesn’t see the current crop of conventional thin films and silicon-based panels as adequate. And, like the leaders of many early-stage companies, he would shift resources from the government’s project development incentives (grants and loan guarantees) to its competitive research and development programs.
His view is representative of a common debate in renewables generally and solar PV specifically: Which is better – focusing on R&D, manufacturing, or project-level deployment to bring down costs?
“In an ideal world, we’d have an appropriate amount of all three,” says GTM Research Senior Solar Analyst Shyam Mehta. “You need all three for different reasons. Spurring innovation is a combination of focusing on existing technologies and coming up with new ones – but clearly deployment-based incentives give early-stage companies a chance to scale.”
One of the world’s largest solar manufacturers, First Solar, is a great example of this. The company began working on cadmium-telluride thin film modules in 1984. But it wasn’t until the 2000’s, when Germany implemented a feed-in tariff to encourage rapid solar development, that First Solar was able to scale manufacturing to dozens of MW of capacity. A couple years ago, the company became the first ever to manufacture a module below $1 per watt and reach over 1,000 MW of production capacity.
“First Solar’s success had a lot to do with factors outside the company’s control. Had there not been robust demand for projects in Germany, they wouldn’t have been able to scale up like they did,” says Mehta.

to be continued