By Eric Wesoff
While the recent solar market has its dark side (bankruptcies, layoffs, slim profits, and consolidation), the industry continues to innovate and drive device performance ever upward. Some of the following milestones represent "hero experiments", but nevertheless - the numbers keep rising.
That means that when the solar sector makes it through these lean times, it will possess increasingly higher efficiencies and even lower price-per-watt metrics than today's already surprisingly low numbers.
These performance records are occurring across the board in every photovoltaic materials system, from CdTe (Abound) to CIGS (MiaSolé) to CIS (Solar Frontier) to GaAs (Alta Devices) to triple-junction CPV cells (Solar Junction and Semprius) to crystalline silicon (SunPower).
Here are some recent announcements of record-setting results:
Solar Frontier is number two in thin-film solar and number one in the CIGS/CIS race, with 577 megawatts shipped in 2010. The firm just racked up a 17.8% aperture area efficiency on a 30-centimeter-square CIS-based PV submodule. The result was claimed to come on a "fully integrated submodule" performed with processes "very similar to what is in place" in Solar Frontier's factories at commercial production scale, according to a release from the firm. The Japanese firm's Kunitomi factory recently built a champion module at 14.5% aperture efficiency, equivalent to a 13.3% module efficiency.
First Solar (FSLR) hit a new world record for CdTe PV module efficiency with a 14.4% total area efficiency in January. That mark comes six months after First Solar hit a CdTe solar cell efficiency of 17.3%. Both records were set at the firm's Perrysburg, Ohio factory.
Alta Devices' most recent gallium arsenide (GaAs)-based solar panel boasts 23.5% efficiency, as verified by the National Renewable Energy Laboratory (NREL). The firm claims that "this is the highest solar panel efficiency yet achieved." The press release did not discuss the size of the panel and the company has not yet responded to our inquiry.
Alta Devices has won more than $120 million in venture funding from August Capital, Kleiner Perkins Caufield and Byers, Crosslink Capital, DAG Ventures, NEA, Presidio Ventures, Technology Partners, Dow Chemical, AIMCo, Good Energies, Energy Technology Ventures, and Constellation Energy. The firm is still in the pilot manufacturing phase.
Chris Norris, the CEO of Alta, has said that the company's goal is to "compete with fossil fuels without government subsidies" and get to a levelized cost of energy of $0.06 to $0.07 per kilowatt-hour. The epitaxial lift-off technique pioneered by Alta founder Eli Yablonovitch allows the firm to produce layers of GaAs that are flexible and measure only one micron in thickness.
SunPower (SPWR) has been the heavyweight champion of the world when it comes to commercialized cell and module efficiencies for the last half-decade - and by a significant measure. The company's back-contact crystalline silicon cell design, in commercial production since 2005, moves the metal contacts to the back of the wafer, maximizes the working cell area, and eliminates redundant wires. SunPower has been able to achieve consistent improvements in efficiency with each successive generation of commercialized cells, and this has translated to gains in the module arena, as well. The firm's Gen 3 cells have efficiencies in excess of 23%.
MiaSolé, a CIGS thin-film PV manufacturing startup, placed third in CIGS panel production in 2011, behind Solar Frontier (at 577 megawatts) and Solibro (at 95 megawatts), according to GTM Research. The firm just announced a 17.3%-efficient champion device, while the "manufacturing process for 14% efficiency is now in production." The firm is making a rare presentation on Wednesday night in Palo Alto, California to the Silicon Valley IEEE PV Chapter.
Solar Junction, a developer of multi-junction cells for high-concentration photovoltaic (HCPV) applications, is working with Semprius and has inked an agreement to deliver multi-megawatts of epitaxial wafers. Semprius claims to have set the world-record CPV solar module efficiency using Solar Junction's III-V multi-junction solar cells based on lattice-matched dilute nitrides. The firm recorded a module efficiency of 33.9 percent.
Abound Solar, a manufacturer of cadmium telluride PV modules, announced the production of 82.8-watt modules at its Longmont, Colorado factory, representing a 12.2% aperture efficiency that is now being verified by NREL. The units were produced on "existing production equipment," according to the firm's press release. The start-up looks to begin mass production of 82-watt modules in the second half of 2012. Abound claims to have produced its one-millionth module in December 2011.