SunPower’s new C7 Tracker uses less than one-quarter the amount of its photovoltaic cells than its flat modules need to produce a roughly equivalent amount of electricity. The net effect is a lower levelized cost of electricity (LCEO). The company unveiled the new device at Solar Power International on Oct.18.
The tracker uses mirrored reflectors to concentrate the sun seven times on rows of SunPower’s Maxeon photovoltaic (PV) cells, increasing their performance while cutting the amount of cells needed to produce the similar amounts of power.
“We can build a 400-MW power plant using less than 70 megawatts of cells,” said Matt Campbell, SunPower’s director of utility products.
Put another way, the C7 system needs less than 17.5 percent of the PV cells compared to a regular module.
It’s another way to squeeze the most out of the smallest amount of silicon as possible.
“We can essentially reduce the amount of semiconductor material to equivalent or less than thin-film. This is less than 1 gram per watt of silicon,” Campbell said. “It allows us to deliver the lowest cost of electricity for the power plants. It’s like a thin-film for material usage but with the efficiency of a SunPower panel.”
The concentrating system uses SunPower’s crystalline-silicon market-leading Maxeon cells, and boosts their efficiency from 22.4 percent.
“It’s the same cell. The difference is that the Maxeon cell, when it has concentrated sunlight on it, it goes up in efficiency to 22.8 percent,” Campbell said. The efficiency of the cells peak at seven times concentration before falling off.
By using their existing cell technology, SunPower’s able to extend the amount of power it can produce from its current manufacturing capacity of 1 gigawatt of cells annually.
“We can use our existing capacity and continue to grow dramatically in the utility power space, without having to build more factories,” Campbell said.
C7 was also designed with the future in mind.
“One of the things we designed into the product is basically a path for future upgrades,” Campbell said.
Since the PV cells are a small part of the system’s cost, it made sense to make them replaceable as future PV cells become more efficient.
“You could turn a 100-megawatt plant to a 120-megawatt plant,” he said.
Such upgrades will help make the system viable for 50 years or more, according to Campbell. This makes it more like conventional power plants which see continual upgrades over their lifespan.
Image courtesy of SunPower.