SolarCity today said it has manufactured the world's most efficient rooftop solar panel.
The photovoltaic panels have an efficiency exceeding 22%, the company said, 7 percentage points higher than the average rooftop panel efficiency rating of roughly 15%.
"The new SolarCity panel generates more power per square foot and harvests more energy over a year than any other rooftop panel in production and will be the highest volume solar panel manufactured in the Western Hemisphere," the company stated in its news release.
SolarCity is headed by Tesla Motors CEO Elon Musk. It was founded by Musk and his cousins Peter Rive and Lyndon Rive.
SolarCity said it will begin production of the new solar panels in small quantifies this month at its 100 MW (megawatt) pilot facility in Fremont, Calif. The company, however, eventually plans to begin mass production of the panels in its 1 GW (gigawatt) facility in Buffalo, N.Y.
The 1 GW facility is expected to produce from 9,000 to 10,000 solar panels per day once it's running at full capacity, SolarCity stated.
According to SolarCity, the new panels were measured as having a 22.04% module-level efficiency by Renewable Energy Test Center, a third-party certification provider.
The new panels produce 30% to 40% more power over the current models, but they cost the same to manufacture -- about .55 cents per watt, according to SolarCity spokesman Jonathan Bass. The panels, which are 1.61 meters or 1.81 meters in size, depending on the model, will have a capacity of 355 watts each.
SolarCity's panel also performs better than other modules in high temperatures, which allows it to produce even more energy on an annual basis than other solar panels of comparable size, the company said.
SolarCity expects to produce between 9,000 and 10,000 solar panels each day when the Buffalo facility reaches full capacity, which should be in early 2017, according Bass.
Tyler Ogden, an analyst with Lux Research, said SolarCity's claim of producing a panel with world-record efficiency of 22.04% "is legitimate."
SunPower, also a manufacturer of high-efficiency crystalline silicon photovoltaic cells, roof tiles and solar panels, had previously claimed the number one spot.
SunPower's X-Series panel have an efficiency of 21.5%, so it falls into second place.
"However, manufacturers continuously improve their production processes and it is likely that SunPower has been able to incrementally improve the initial reported efficiency," Ogden said.
Solar panel manufacturers are pushing the limits of efficiency gains, pursuing improvements and technologies that yield an increase of a few tenths-of-a-percent, Ogden said.
Incremental gains in efficiency increase the value of the solar panel, enabling it to produce more electricity over the panel's lifetime.
"SolarCity's achievement of a 22% efficient panel is significant, but even more valuable is their claim of producing 30%-40% more electricity than a standard panel at the same size," Ogden added.
SolarCity's new panels use the same photovoltaic cells as its previous model panels, but the company's engineering team was able to squeeze more photovoltaic cells into the same area and arranged them to minimize energy loss, according to Ben Heng, SolarCity's senior vice president of product engineering.
"It's all fine and good and fundamental to work on the solar cell technology, but sometimes we forget there is low hanging fruit or less fundamentally challenging methods to improve the overall efficiency of the product," Heng said. "In this case it was the packaging."
SolarCity also claims its panels don't suffer efficiency losses due to increases in temperature to the degree that other panels do.
"That was a claim that had previously been monopolized by thin-film modules, like those produced by First Solar and SolarFrontier," Ogden said. "That could be a key differentiator in hot climates."
SolarCity initially expects to install the new panels on rooftops and carports for homes, businesses, schools and other organizations, but it will also be excellent for utility-scale solar fields and other large-scale, ground level installations.