It has been said that solar energy is the future of energy and always will be. But growing concern about climate change and high oil prices is generating new interest in ways to more efficiently capture the power of the sun. Two provocative items on this front recently caught my attention.
One is a joint effort among Stirling Energy Systems, Boeing, and the Department of Energy to capture the sun's rays using a Stirling engine, a device first invented in the 19th century. Stirling engines are powered by the expansion of gas when it is heated inside the engine, followed by the compression of the gas when cooled. The gas never leaves the engine but moves back and forth between the hot side and the cold side, moving a piston. One way to heat the gas would be to use solar power—the goal of the project, which uses solar dishes to focus the sun's rays on the engines. (The following link plays a video of the dishes in action.) As this EE Times analysis theorizes, one day a 100-by-100-mile farm of these dishes could supply all of America's daytime energy needs.
Then there's this recent piece of news from the University of Toronto where researchers have developed "spray on" photovoltaic materials using nanoparticles sensitive to infrared rays. This potentially allows the creation of solar cells that can harness five times more of the sun's energy. As reported in the journal Nature Materials, the substance potentially could be applied to existing surfaces like walls or clothing.
