Concentrated Solar Panels Has Efficiency of 25%

Ammonix received $129 million in venture funding to further its commercialization of concentrated photovoltaic technology.

Ammonix uses 23.5 by 15 meter arrays, covered in plastic Fresnel lenses that concentrate the sun 500 times.   The concentrated sunlight is focused on an ultra-efficient multi-junction solar cell (made by Spectrolab with a 41% efficiency rating in lab tests).   To further enhance performance Ammonix uses a tracking system to keep the lenses pointed within .8 degrees of the angle of the sun throughout the day.

While the efficiency ratings are quite high, there is some concern about reliability given the devices high level of complexity, specifically as the lenses require very precise alignment of the sun to focus light on the solar cells. "The difference between being in alignment and being one degree off is the entire system works or it doesn't," says Johanna Schmidtke, an analyst with Lux Research.

Read the full article and comments here at Technology Review.

Editor's note:   One of the comments to this article suggests that the drop off in efficiency from 41% to 25% ... is caused by the the inefficiency of the flat plastic Fresnel lenses.