New Solar Thermal Technology in Tokyo
New solar thermal advances in Tokyo. Photo Credit: JapanFocus
Researchers at the Masdar Institute in Tokyo have developed a new variation on concentrating solar power (CSP) technology. Power towers (CSP plants in which flat, heliostat mirrors concentrate sunlight onto a central tower filled with water) are receiving a lot of attention right now because they require less land area than parabolic trough designs. Power towers stand out because of their height, reaching hundreds of feet into the air, but Masdar researchers plan to save energy and cost by greatly reducing that height and adding one more relay of mirrors.
Rather than pumping water or molten salts to and from the high receiver tower, the idea is to keep it close to the ground, where less energy is needed to pump water and less material needed to build the tower. So a tall tower filled with water is replaced by a much shorter tower with mirrors mounted to it, creating highly pressurized steam to drive an electricity-generating turbine.
The upside to the Masdar design is energy- and cost savings. Instead of the laborious process of building an incredibly tall tower and a pump system to circulate water, you build a cheaper, shorter tower; a current prototype is only 10 meters tall. The downside is that in adding an extra step - forcing sunlight to be reflected twice - you lose some efficiency. Typical solar thermal power plants have efficiencies well over 20 percent, while the Masdar version is reduced to 15-19 percent, a loss that proponents say is made up for with other savings.
Masdar Institute hasn’t even finished building their prototype, with water tanks yet to be installed, but they estimate that the finished product should produce about 100 kilowatts of solar power. This sort of thermal technology has been experimented with in the past, but no one outside of the Masdar Institute is working on it now. The 100-kW prototype is obviously a test model, and depending on how well it works, researchers say larger versions could generate 10 megawatts. Fields of these reflective towers could generate 50-100 MW of clean solar thermal electricity.
Via Greentech Media
Interested in Home Solar Energy?
Remodeling tweets and photos posted daily. Join Us on Twitter