News Picks : Concentrator increases efficiency of solar panels
MIT Technology Review: A novel material could make solar power cheaper and more efficient. Glint Photonics is developing a “self-tracking solar concentrator,” which could obviate the need for the extensive equipment, lenses, and mirrors currently required to track the Sun and focus its rays. Glint’s system uses an array of lenses to concentrate sunlight on a sheet of glass coated with a special, reflective material. The material heats up where the Sun strikes it, which changes its optical properties in that spot so that it ceases to be reflective. As the angle of the Sun changes throughout the day, sunlight can enter the glass at any point, while the rest of the surface remains reflective. The trapped light is redirected to the edge of the glass sheet, where a small solar cell is mounted. Besides eliminating the precise alignment needed by most other photovoltaic systems, the device is inexpensive and simple to manufacture. Work remains to be done, however, to decrease the amount of sunlight that gets absorbed or reflected en route to the device.