Monday, February 15, 2010

Solar Energy Harvesting Using 1 Percent Of Current Materials

Imagine a world where sunlight can be captured to produce electricity anywhere, on any surface. The makers of thin-film flexible solar cells imagine that world too. But a big problem has been the amount of silicon needed to harvest a little sunshine.

Now, researchers [led by Harry A. Atwater] at Caltech say they’ve designed a device that gets comparable solar absorption while using just one percent of the silicon per unit area that current solar cells need. The work was published in the journal Nature Materials.

The research team tried silicon wire arrays instead of traditional silicon panels. These wires have been shown to do a good job converting sunlight to usable energy on the nanoscale. But the scientists had to create wires a thousand times longer.

Light bounces around within the wires and is eventually absorbed when it hits at the correct angle. But there was a problem: too much light was leaking out. Adding nanoparticles of alumina kept much more of the light scattering until it got absorbed. The result is a system that virtually matches silicon wafer light absorption and may be more efficient at converting light to electricity, while using a tiny fraction of the material.—Cynthia Graber

Source (PodCast)

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Wednesday, July 01, 2009

Solar Thermal Farms

An interesting video about Solar Thermal Farms, on Greentech Media:

Hot Times in Solar Thermal
BrightSource Energy CEO John Woolard sketches out the future of power from the desert.

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Monday, May 05, 2008

Emissions from solar power technologies continue to fall

Emissions from solar power technologies continue to fall

Photovoltaic (PV) technologies which harness solar energy in solar power installations are making rapid progress. The latest life cycle analysis of four current PV systems shows a trend for all of these to have significant and increasing environmental benefits in terms of reducing emissions compared with conventional electricity production.

All forms of electricity generation create emissions at some point during their life cycle. PV systems generate sulfur dioxide, carbon dioxide, and nitrogen oxide emissions, resulting from the fossil energy used in production. The production of PV systems is also responsible for toxic metal emissions, including arsenic, cadmium, chromium, lead, mercury and nickel, as all these elements are present in fossil-fuels.

Full article at environmental-expert.com

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