Two Birds With One Stone (But No Birds Actually Harmed)
Solar water heaters make a lot of sense. Solar photovoltaic panels make a lot of sense too. But why choose between them? Startup Cogenra is combining the two solar technologies in its solar arrays, increasing the total amount of solar energy that can be captured (and thus reducing reliance on other sources of energy that aren't as clean). It's a very clever system, and if it works well, I hope most solar arrays that are close enough to a user of hot water will be like that in the future (obviously, it wouldn't work if the array is in the middle of the desert).
Here's how it works:
Traditional photovoltaic (PV) systems convert approximately 16% of the sun's energy into usable electricity, discarding the remaining energy as waste, mostly in the form of heat. Solar cogeneration captures this waste heat and transforms it into real value--hot water. This cogenerative solution has the added benefit of cooling the PV components, which boosts the system's electric generation.
Solar cogeneration translates the sun's wasted thermal energy into an asset that generates further savings.
Cogenra has developed an extensive intellectual property portfolio covering its solar cogeneration technology. Cogenra Solar's proprietary technology captures up to 80 percent of the sun's delivered energy and produces five times the energy of traditional PV systems. To achieve these dramatic efficiency gains, Cogenra integrates advanced silicon PV cells, concentrating optics with single-axis tracking and an innovative thermal transfer system in a low-cost and scalable design.
Vinod Khosla has invested $10.5 million in the project via Khosla Ventures. He says that the technology is remarkably cost-effective, which is exactly what it needs to compete the energy market, not only against other solar vendors, but also against other sources that have unfair advantages (coal is cheap because of 'externalities' like air pollution and greenhouse gas emissions).
So far Cogenra has installed one solar array at a winery in California. It can produce 50 kilowatts of electricity and the equivalent of 222 kilowatts of thermal energy.
Via Cogenra, Technology Review
More on Alternative Energy
South-Korea to Invest $8.2B In Massive Offshore Wind Farms
Stirling Engine Made with Soda Cans Spins to 860 RPM (Video)
Algenol's Algae-to-Ethanol Delivers 67% to 87% Reduction in CO2
Dr. Steven Chu Answers Questions from Citizens About Energy Conservation (Video)
Should Energy Conservation be Framed in Terms of What Would be Lost?
2009 Snapshot of U.S. Energy Use by Lawrence Livermore National Laboratory
If you like this article, you can follow me on Twitter (@Michael_GR) and Stumbleupon (THMike). Thanks.