Harnessing the Sun’s Power without Solar Cells
William Fisher, a University of Michigan doctoral student, performing research on light-induced magnetism.
Despite the promise of solar power, the technology remains expensive and inefficient. One of the financial impediments is the expense of crystalline materials used to absorb heat and convert it to electricity. A recent study by University of Michigan scientists demonstrates that solar power may be harnessed simply by magnifying the source of light rather than using solar cells. The researchers’ so-called “optical battery” focuses sunlight to an intensity of 10 million W/cm2, which in turn creates a strong magnetic field that generates electricity.
"This could lead to a new kind of solar cell without semiconductors and without absorption to produce charge separation," said electrical engineering professor Stephen Rand. "In solar cells, the light goes into a material, gets absorbed and creates heat. Here, we expect to have a very low heat load. Instead of the light being absorbed, energy is stored in the magnetic moment. Intense magnetization can be induced by intense light and then it is ultimately capable of providing a capacitive power source."
The study proposes using glass lenses and fibers to harness the light, and adds that transparent ceramics may offer even better performance in the future.