Green Technology

Here is a new "twist" on the design of solar

cells that allows for a longer "sweet spot" of power generation.

>> The "twist" is that instead of being flat these solar cells are 3-D.

"Solar cells generally crank out the most power at noon, when the sun is at its highest point and can strike the cell at a 90-degree angle. Before and after noon, efficiencies drop off. But researchers [at] Georgia Tech Research Institute ... prototype ... whose surface consists of hundreds of thousands of 100-micrometer-high towers, catches light at many angles and actually works best in the morning and afternoon."

"... When the sun is at a 90-degree angle, the prototype delivers only 3.5 percent efficiency. ... and is actually at its peak efficiency--7 percent--when light comes in at a 45-degree angle. That means the device operates at relatively high efficiencies during much of the day and has two efficiency peaks: one before noon, and one after noon."

"While those efficiencies are too low for commercialization, ...  working on optimizing the size and spacing of his towers as well as their chemical composition. As a first application, his sights are set on powering spacecraft and satellites, which could benefit from solar cells that don't require a mechanical means of moving the orientation of the cell to keep it facing the sun."

More info at Georgia Tech Research Institute Link 

Via:  MIT Technology Review   Link