First Solar Inc of Tempe, AZ, USA has raised its world record for cadmium telluride (CdTe) photovoltaic (PV) module conversion efficiency to 18.6% aperture efficiency for a full-size module, as measured and certified by the US Department of Energy's National Renewable Energy Laboratory (NREL).
The firm says that, for the first time ever, a module has been demonstrated that is more efficient than the best multi-crystalline module recorded. The 18.6% aperture-area efficiency corresponds to a full-area conversion efficiency of 18.2%, beating the best recorded multi-crystalline silicon PERC (passivated emitter rear contact) module with an approximate full-area efficiency of 17.7% (based on 19.1% aperture efficiency and published module area data).
This is the First Solar's eighth substantial update to CdTe record efficiency since 2011. In January, it produced a research cell with 21.5% efficiency, certified at Newport Corp's Technology and Applications Center (TAC) PV Lab and confirmed by NREL.
"At one time, we might have been characterized as a low-cost, low-efficiency technology, but consistent with our technology projections we are now proving that CdTe thin film delivers both industry-leading performance and sustainable thin-film cost structures," says chief technology officer Raffi Garabedian, who emphasizes that First Solar's significant sustained investment in development of CdTe technology has enabled it to meet or exceed its aggressive projections for improvements in research cells and modules, as well as commercialized technology.
"While silicon technologies have approached their theoretical efficiency entitlement and leveled out in terms of performance and cost, First Solar continues to harvest the upside available from its superior thin-film technology," Garabedian says. "Our CdTe modules are now more efficient than the best multi-crystalline Si modules, and we still have a great deal of technology head room for further innovation," he adds.
Efficiency, combined with other real-world performance attributes, results in First Solar technology delivering higher energy density than multi-crystalline silicon (m-Si) solar panels, notes senior manager of technology Nick Strevel. Given the same installed nameplate module capacity (Watts) with equivalent ground coverage ratio, First Solar's CdTe product will provide up to 8% more useable energy from the same land area than m-Si, he adds.
"A narrow focus on simple metrics such as standard-test-condition (STC) efficiency or cost per STC-watt obscures the actual value of solar generation technologies," says Strevel. "Customers value energy produced by a solar power plant (kWh), not its nominal STC power rating. Metrics with greater relevance to real-world conditions - including specific energy yield, energy density, cost/kWh and long-term reliability - ultimately tell a much more comprehensive story of real-world performance and are more influential in reducing levelized cost of solar electricity [LCOE]."
Strevel adds that First Solar's modules have also passed the industry's most rigorous multi-stress testing protocols such including Atlas 25+, IEC Long Term Sequential and Thresher Tests.
