Amonix, which makes concentrating photovoltaic (CPV) systems, has once again broke a world record for real-world efficiency testing. In real-world testing, the company’s latest CPV technology reached a peak conversion efficiency of 36.2 percent at the National Renewable Energy Laboratory (NREL) in Golden, Colorado. The new record broke Amonix’ former world record of 34.2 percent by 2 percent.
The new technology tested higher during the whole testing period from February to April. “Over the entire testing period, the Amonix module earned a National Renewable Energy Laboratory outdoor efficiency rating of 34.9 percent, a new world record, under international standard operating conditions for concentrator photovoltaics,” Amonix said. The testing module used Boeing Spectrolab’s 40 percent high efficiency solar cells.
“Amonix’s proprietary technology platform allows us to continue driving rapid performance improvements in our CPV system,” said Vahan Garboushian, Amonix founder and CTO. “The advances we have demonstrated over the last two years have all been with the same generation 40 percent cells, demonstrating an unprecedented cell-to-module conversion efficiency of greater than 90 percent,” he said. The advances show that the efficiency growth has come from Amonix’ innovations rather than more power multi-junction cells.
“With improvements that are underway in cell efficiency and additional advances in our module technology, we will continue to drive efficiency higher over the coming years,” Garboushian said. To help drive that efficiency, the company is making partnerships with companies like Solar Junction to help bring down the costs of the advanced cell technology.
While most commercial photovoltaics (PV) are silicon-based, Amonix and some other companies are using specialized, multi-junction PV cells, like gallium arsenide (GaAs) PV cells. These specialized cells are able to convert more of the sun’s light into electricity on various layers of the cell. The theoretical conversion efficiency limit for a single-junction silicon PV cell is around 33 percent and the most efficient silicon PV cells on the market are able to convert about 24 percent of the sun’s energy into electricity. However, Amonix partner Solar Junction’s cells have converted 44 percent of the sun’s energy into electricity.
Most multi-junction PV cells are much more expensive because of the rare material they are made out of. Therefore, these specialized cells are not really suitable for modules on rooftops. In fact, their primary use has been for space applications. Now companies like Amonix are concentrating sun on these multi-junction cells to get the most out of them. For instance, Amonix’ previous generation MegaModules concentrated the sun on each small PV cell over 500 times. One MegaModule consisted of 36 sets of lenses and receiver plates that were assembled into the larger 7700 MegaModules, which—at 77 feet by 49 feet—were larger than an IMAX screen.