It seems a day does not go by without a major new solar innovation hitting the market. I just returned from Cleantech Open's Green Building Symposium and discovered three more new technologies. So I've decided to create a bunch of individual posts, each illustrating one new solar technology. In a few months, I'll compile these into the top 10 coolest solar innovations. Today's technology is from Sanyo.
Last year Sanyo wowed the solar world with their HIT panels, breaking the world's record for solar panel efficiency by hitting a 22% photovoltaic efficiency (22% of the sunlight that hits the panel is converted to energy). The technology is called HIT which stands for Heterojunction with Intrinsic Thin layer. That means unlike other photovoltaic cells, the Sanyo combines thin-film technology with a regular crystalline cell by sandwiching the PV cell between amorphous thin film layers.
HIT has the added advantage of giving the cell a higher heat performance, a problem that has troubled photovoltaics since their inception. Normally in hot climates, where you have the best solar access, you also get reduced efficiency of the cell because solar cells perform much better in cold temperatures. The Sanyo HIT panel allows the panels to operate at peak performance up to 115 degrees. This means people in Southern California, Arizona and Texas will be able to see much quicker returns on their solar investment because they will now be able to convert much more energy during those hot summer months.
Sanyo pushed it even farther this year when they introduced the double-sided (or "bifacial" as they call it) HIT panel. By coating the bottom side of the panel, they take advantage of ambient reflected light bouncing off of wall and floor surfaces for use in awnings, carports, walkways, and deck coverings. You wouldn't think that this would generate much electricity, but in fact the 2-sided panels have been showing an astonishing 30% conversion (depending upon location and orientation).