سلطة الطاقة و الموارد الطبيعية الفلسطينية

Solar Junction is a company that was started a few years ago in 2007 with the intention to design and develop continued and sustained solar technology products for the Concentrated Photovoltaic (CPV) industry. The company is focussed on continuing to develop lattice matching technology for next generation solar cells, and the company has recently achieved what could be called a breakthrough in efficiency for its solar technology products.

The U.S. Department of Energy’s National Renewable Energy Laboratory has recently confirmed a 41.4% conversion rate on a sample from the company’s multijunction cell poduction line. The company’s director of business development, Jeff Allen, said that after after some tests concluded about two weeks ago, the cells exceeded 41% peak efficiency. It seems the company has been continually improving on their product after it had achieved a NREL-verified 40.9% efficiency on the cells tested about one month ago during March 2011.

The cell tested, was taken from their production line and featured an aperture area of 5.5mm × 5.5mm, which is able to be immediately integrated into many of their existing clients’ modules. Larger and smaller cell sizes can also be produced. And, in their most recent tests, the Silicon valley solar company said that it had measured an achieved 43.5 percent peak efficiency rate, toppping all the previous records. To do this, Solar Junction designed a multijunction cell which is basically made up of multiple layers photovoltaic material.

What makes this interestng is that each layer is made so that it converts a different portion of the spectrum of sunlight that reaches it. To further optimize this, the receiving light is concentrated with mirrors to increase the absorption rate. The small cells are only 5.5-millimeter square cells after all. The 43.5 percent was achieved at a rate of 400 suns and maintained up to 1000 suns.

Multijunction cells have been used for a very long period of time, decades in fact, mostly in spacecraft and for electricity generation in desert areas. This company seems to have their sights set on becoming a major player in supplying these valuable components to manufacturers in the solar industry.
Apparently concentrating solar thermal technology is slightly less effective than multijunction cells. If you have more information or want to comment on this subject, please feel free to leave your comments below.

In the image featured above, each one of these chips can produce the equivalent of about 20 watts. Photo credit: Solar Junction