They are calling it the “most efficient rooftop solar module in the world.”

Residential solar company SolarCity announced that its Buffalo, New York “gigafactory” will be producing solar panels that are more efficient — and 30 percent more powerful — than its previous version.

This is good news for customers. Using more efficient, more powerful modules means homeowners will get more bang for their buck, so to speak. Installation costs go down. Hardware costs go down. SolarCity wins, too, of course.

Keith Emery, a scientist at the National Renewable Energy Laboratory, called the announcement a “very significant advancement, which should lower their cost, which should at the very least improve their profit — and I assume they will pass that on to their customers.” The module’s efficiency rate is comparable to other leading modules, Emery said.

Solar prices keep coming down. Average installed costs have fallen 9 percent since last year, according to the most recent report from the Lawrence Berkeley National Lab. The cost of residential solar has dropped 50 percent in the past five years. Economies of scale will also help push costs down, Emery said.

Read full story…