Solar concentrators are nothing new and researchers have long supported their use in an effort to increase the energy produced by a solar cell, without increasing the cost by much. However, most solar concentrating systems rely on expensive infrastructure such as trackers and heavy mirrors that require specialized services for installation and maintenance. Cool Earth Solar is now trying to reduce the cost of solar concentrating systems by developing inflatable solar concentrators that are made using inexpensive and free materials. This unique design approach radically reduces material requirements as well as cost and time required to bring them to use.
The solar concentrators are made using inflatable, tube-shaped plastic film similar to the one used commercially for packaging and shipping. Each inflatable tube, which is about 3 feet in diameter and 24 feet long, contains solar cells running across the length, either in a continuous strip or spaced six inches apart. Once inflated with air, the concentrator naturally forms an ideal solar concentrating surface that directs and concentrates light to the PV cell placed at the focal point. The company claims that a single cell inside the concentrator generates up to 1200 times more electricity than a similar solar cell without a concentrator.
Despite the fact that the concentrating surface is made using plastic, it is claimed to be strong enough to support a person’s weight and is aerodynamically designed to enable it to withstand high speed winds. Moreover, the tube also protects the energy generating surface from rain, snow, insects and dust. To keep the interior temperatures stable, the system includes a simple heat sink and also comes with a small air pump for maintaining the desired air pressure.
The company has now entered a partnership with Sandia National Laboratories to test the new technology over the next five years at Sandia’s Livermore Campus. Only after the successful completion of the tests, the company will be able to verify the cost per watt of solar energy that the system can generate. Moreover, since the system requires adequate air pressure to be maintained at all times, it would be interesting to see what the company has on offer if the system is to be placed in remote locations where maintenance could be a nightmare.