Energy Conversion Devices (ENER) has a subsidiary, United Solar Ovonic, that makes the highest efficiency thin-film photovoltaic (PV) cells for solar-generated electricity. Solar modules traditionally are made of polysilicon cells that are mounted in a metal frame, covered with protective glass and wired together for connection to each other in PV arrays. It's an expensive, mechanical assembly process. Combined with a shortage of polysilicon, it has kept the cost of generating solar power about five times as high as the petroleum-based alternatives.
In the mid-1990s, AstroPower developed a continuous film coating process to put the polysilicon on films that could be attached to a prewired frame and shipped as a module. I had these modules in an array on my ranch in Half Moon Bay, and they worked great. But they were still about triple the cost of conventional electricity, and if it hadn't been for a 70% co-payment by Pacific Gas & Electric and the taxpayers of the State of California, I wouldn't have done it.
United Solar Ovonic takes that idea a step further to deposit a thin film of amorphous silicon, not the hard-to-get polysilicon, in a continuous process that produces a roofing material usable in new or retrofit construction. It has about 16% efficiency these days, and it is cost-effective under the current Energy Bill tax incentive of 30% of cost.
The reason I brings this up is because recently, I've had a couple of questions about nanosolar, applying nanotechnology to greatly reduce or even eliminate the need for silicon. The other week, a technology breakthrough at an Israeli nanotechnology institute caught my eye. They used conductive glass -- no silicon -- and nanodots of platinum to produce PV cells 100 times as large as current cells. They reduced the amount of expensive platinum needed to make a solar cell function by 97.5%.
The institute is working with a private Israeli company, Orion Solar, to develop the technology. This is just one of hundreds of similar innovative programs at research institutes, universities and private companies happening today, all around the world.
