SunPower Corp. will deploy a 1-megawatt solar power plant using its new C7 Tracker concentrating photovoltaic (CPV) technology at Arizona State University’s (ASU’s) Polytechnic campus in Mesa, Ariz. It’s the first commercial-scale deployment for the system, which promises to lower the cost of SunPower’s photovoltaics by using less PV cells.
The array is being designed and built by SunPower, and Salt River Project (SRP) will buy the electricity produced by the system under a power-purchase agreement. It will resell the electricity to ASU under a separate contract.
“Phoenix, Arizona, is an excellent location for a CPV system given its high annual direct normal solar resource,” said SunPower Senior Director of Business Development Matt Campbell. “ASU and SRP are leaders in solar PV, so they made natural partners for the project. SRP was SunPower’s first utility customer for its tracking system, over 11 years ago.”
The system uses mirrors to concentrate more solar radiation on SunPower Maxeon PV cells, which are the most efficient silicon-based PV cells on the market today, operating at 22.8 percent conversion efficiency. The C7 tracker is so dubbed because it concentrates the sun on the cells seven times. Which means the 1-megawatt system will use only 172 kilowatts of SunPower’s cells, thereby lowering the levelized cost of electricity (LCOE) of the system.
However, there is some loss in the system through reflective factors.
“The concentration on the cells is seven suns but the cell multiplier effect is 5.8 [1,000/172],” Campbell said. “The reason is due to reflective losses in the system such as from the glass mirrors.”
The system is being designed based on SunPower’s Oasis power block design, which uses its standard modules and has the highest energy density of any PV tracking system, according to Campbell.
“The C7 trackers are placed slightly further apart which increases the amount of land required by about 20 percent. The C7 requires about 5.2 acres per MW. This is still about 25 percent less than standard efficiency PV,” he said.
Since the system is designed based on the company’s Oasis power block, the installation will be similar, Campbell said.
“The installation time will be similar to the conventional SunPower Oasis power block system,” he said. “The C7 has been designed for very rapid assembly.”
While this will be the first commercial deployment for the C7 Tracker, the company already is working on bigger projects with the technology, according to Campbell.
“We’re talking with major utilities all over the world, with delivery beginning this year,” he said.
Ideal markets will include the U.S. Southwest and parts of the Middle East, Africa, Europe, Asia and Australia.