The race for bragging rights for the world’s best rooftop solar module has been heating up in the last several days, which three different manufacturers asserting that their design is the most awesomely efficient of them all at converting sunlight to electricity.

Earlier this week, Panasonic claimed 22.5% for its new HIT N330 module, a 72-cell, 270-watt prototype that it plans to introduce in the UK. “The panel’s 22.5% conversion efficiency was verified by Japan’s National Institute of Advanced Industrial Science and Technology (AIST), and builds upon the 25.6% efficiency record the company set in 2014 at cell level,” PV Magazine reports. At mass production volumes, the modules are 19.7% efficient.

But two U.S. companies are also in the race, Greentech Media reported last Friday. SolarCity, which acquired solar module start-up Silevo in June 2014, is reporting 22.04% efficiency for modules assessed by the Renewable Energy Test Center in Fremont, California. Co-founder and Chief Technology Officer Peter Rive “acknowledged that the 22% panel is ‘on the high end,’ but also noted that a majority of panels are hitting 21.8%,” writes Greentech Editor in Chief Eric Wesoff.

The company says the module will be “the highest-volume solar panel manufactured in the Western Hemisphere,” with 9,000 to 10,000 panels rolling off assembly lines each day once its planned gigawatt-scale factory in upstate New York reaches full capacity.

Meanwhile, San José-based SunPower calls its X-Series panels the “most efficient panel on the market today,” with average efficiency in the 22 to 23% range and production volumes set to triple in one year.

“As a company that is leading in providing customers around the globe with the world’s most efficient solar panels, SunPower always welcomes others to the efficiency race,” a company spokesperson said. “It’s great that we all agree—efficiency matters.”