High Concentration Solar PV Module ( Solar Thermal Magazine) – We thought it would be interesting to take a deeper look at one high concentration solar PV technology company that has been making headlines for the very high average efficiency that they report. The company is Semprius which is located in Durham, North Carolina and they claim to have the highest solar module efficiency of 33.9%.
Here is their statement on efficiency.
Our approach delivers two to three times higher efficiency than traditional solar modules, superior performance in hot climates, industry-leading capacity factors and the highest energy density in the world – all while driving down the cost of electricity and minimizing the impact on the environment.
Concentrating photovoltaic (CPV) modules work in much the same way as traditional PV modules, except that they use optics to concentrate the sun onto solar cells that do not cover the entire module area. This concentration factor for the Semprius model according to the company is over 1,100 times. This magnification dramatically reduces the amount of semiconductor needed (<0.1 percent) and opens up the potential to cost-effectively use very high-performance multi-junction cells with efficiency levels greater than 41 percent.
In order to work properly, however, CPV modules must accurately face the sun. Therefore, CPV modules are used in conjunction with high-performance trackers that intelligently and automatically follow the sun throughout the day. Other than this, CPV systems are built and operate much like traditional PV systems.
Recently, the company claims a new breakthrough in stacked cell design is allowing ever greater levels of efficiency.
The new stacked solar cell is comprised of a three-junction microcell that is stacked on top of a single-junction germanium microcell using Semprius’ high-speed micro transfer printing process, which enables the simultaneous formation of thousands of stacked microcells with very high yields. By using four junctions, the stacked cell is able to capture light across a broader portion of the solar spectrum and therefore achieve efficiencies much higher than conventional silicon and thin-film single-junction solar cells. Initial trials yielded solar cells with measured efficiencies up to 43.9 percent.
This process is capable of achieving solar cell efficiencies greater than 50 percent in the near future.
Yes, you did read it right. 50 %!
A key achievement of this project was the development of a new interfacial material that is placed between the top and bottom cell to minimize optical losses within the stack and thereby optimize overall conversion efficiency. In addition, the new stacked cell has four terminals, rather than the standard two. This reduces the spectral dependence of the solar cell and increases the solar cell’s energy yield under normal operation in the field.
We have added a video of the Joe Carr, CEO of Semprius talking about their technology and it potential to be disruptive to the energy sector coming in at less than 10 cents per kwatt hour.
Just what we need, right?
Gordon's expertise in the area of industrial energy efficiency and alternative energy. He is an experienced electrical engineer with a Masters degree in Alternative Energy technology. He is the co-founder of several renewable energy media sites including Solar Thermal Magazine.