Researchers at the University of Michigan have taken a second look at a long-overlooked rule of physics, and the results could send shock waves through the solar power industry. The team found that a magnetic field could harvest solar energy directly, without the absorption mechanism required by conventional photovoltaic cells. Instead of semiconductors, the magnetic solar cell would consist simply of a long magnetic field contained in a fiber, with a focusing lens to get the right intensity of light.
Magnets and Renewable Energy
The latest breakthroughs in photovoltaic materials, biofuels, wind turbines and geothermal power have been grabbing a lot of headlines lately, but magnetic energy has been quietly emerging as the workhorse of the clean energy world. Magnetic energy can combine with motion to recharge batteries for handheld gadgets, it can eliminate the need for lubricating oil in the design of high tech flywheels, and it can stand in for solder to make a more energy efficient computer chip. The U.S. Navy is also experimenting with a new system that uses magnetic power to recover waste energy from lighting.
Magnetic Solar Power Cell from the University of Michigan
The Michigan research paper is a mouthful — “Optically-induced Charge Separation and Terahertz Emission in Unbiased Dielectrics” — but the basic idea is simple. Given light at the right intensity, you can create a magnetic effect that is as strong as electricity. To collect solar power, this energy would be stored in the “magnetic moment” instead of being absorbed by a material to create heat. The effect, called optical rectification, was previously known to exist only in a far weaker form, in certain crystalline materials.
Better, Cheaper Solar Cells
According to the Michigan team, a magnetic solar battery would involve far less engineering than conventional semiconductor-based solar cells require. The materials would also be relatively cheap, because the focusing lens could be made of glass or transparent ceramic. The leap from research paper to your neighborhood home improvement store is likely to be many years in the future, but there’s no need to wait around for cheap solar energy. The solar power industry is breaking one energy efficiency barrier after another, and cheap solar materials like aluminum are already in use. Even if the Michigan breakthrough never achieves commercial development, the price of solar energy is already competitive with natural gas and coal in some areas, so it looks like the era of fossil fuels is rapidly drawing to a close.
Image: Magnets by TheodoreWLee on flickr.com.
- Solar-Thermal Innovations at Wake Forest (cleantechnica.com)
Tina Casey specializes in military and corporate sustainability, advanced technology, emerging materials, biofuels, and water and wastewater issues. Tina’s articles are reposted frequently on Reuters, Scientific American, and many other sites. You can also follow her on Twitter @TinaMCasey and Google+.