A Funnel For Sunlight
Without a direct stream of light on a solar panel, the efficiency of a the power generated lets up once the sun does as well. A new invention to fix this is a anti reflective film coating that may help panels collect sun at 96 % efficiency from almost any angle. Developed by at Rensselaer Polytechnic Institute, the film consists of seven layers of nanoscopic silicon and titanium-oxide rods arranged in increasing densities, with the topmost nearly as porous as air. This funnel-like setup captures light from almost every direction and focuses it onto the photovoltaic panel while also inhibiting reflection. The film, which is about one hundredth as thick as a human hair, could easily be applied to any solar panel, says lead researcher Shawn-Yu Lin, and would help collect 20 percent more light while eliminating the need for the expensive hardware usually used to rotate solar panels as the sun moves. Before Lin can sell the film, he must find a way to protect the outermost layers from the wind and heat, a process that he says may take another year.
Turning The Tide
Engineers at the University of Oxford recently tested a 1.5-foot-wide prototype turbine that generates energy by spinning in the tide like the blades of a push lawn mower. The cylindrical turbines could be roughly 10 percent less efficient than fan-shaped turbines, but each rotor’s size—the full-size versions will be 33 feet in diameter and 200 feet long—and the ability to link multiple units means they can harness more energy for less money. Spanning an entire river with the six-megawatt turbines could save 40 percent per megawatt on manufacturing and 60 percent on maintenance. The engineers are lining up funding and plan to evaluate a full-scale device next year.
FRICTIONLESS WIND TURBINES
The problem with wind turbines? Often, it’s just not windy enough to get them turning. It’s not really the lack of wind that is the problem, but the friction in the turbines themselves. Chinese scientists may have cracked this problem with the first “magnetic levitation” (or MagLev) wind turbines, which replace ball-bearings with the technology used in advanced monorails, making a frictionless turbine that can generate electricity from winds as low as 1.5m per second. They’re ideal for low wind areas, such as mountain regions and small islands. The MagLev wind turbines could also use the airflow caused by passing cars to generate roadside lighting.