Source: SunPower via NREL
Solar inverters, which are used to convert the direct current (DC) power generated by a solar panel into the alternating current (AC) power used on the grid, are one area that hasn’t seen a lot of innovation since the early days of solar power, at least not at a dramatic scale. But that’s changing, as we’ve noted (more than once) since last fall. There are new technologies that improve the system architecture, simplify the phase conversion process, improve reliability and ease of use, and permit better monitoring.
In the last 10 days, we’ve seen some good announcements out of companies working on new inverters (and other electronics) that help solar panels connect to the grid. PV Powered, an established player out of Bend, Ore., raised a “multi-million dollar investment” this week. Echelon announced a partnership with i.LON SmartServer that’s aimed at moving its energy-monitoring and smart meter technology into the solar market. And startup EnPhase says it may soon be embedding its microinverter technology directly into solar panels. (A new report out from Greentech Media looks at some of the coming innovations, as well.)
In part, this spurt of activity is driven by the capital efficiency of investing in inverters rather than panels; but it’s also part of the bigger push to make our electrical grid smarter. Even before the economic stimulus bill accelerated funding for renewables, the U.S. Department of Energy allocated $24 million to a program known as SEGIS, or Solar Energy Grid Integration Systems, for R&D efforts “that will allow PV to become a more integral part of household and commercial smart energy systems,” as well as “to minimize building energy costs and stabilize the effect on the electricity grid.” Many of the innovators making news this week received funding under this program.
While so far, solar integration hasn’t caused major headaches for most utilities, many — including Pacific Gas & Electric here in San Francisco — estimate that it could become an issue. Because renewables have vary output, sudden weather changes can have dramatic effects on the grid. (Wind, so far, has been the major challenge for utilities.) Rachelle Chong, a California Public Utilities Commissioner, posted notes about a recent smart grid workshop to her Twitter feed last week. With 30,000 solar customers currently, PG&E isn’t worried yet, but Chong notes that as more solar comes online, it could be an issue. Earlier this year, when the Florida Utility FPL announced its high-profile smart grid project with GE, Cisco and Silver Spring as partners, one of the key issues the city said it would explore was integrating renewable energy into the grid, as well. (Cisco, specifically, was tasked with addressing this issue.)
Taken together, these improvements in inverter technology and investment in smart grid technology could be the first gusts of a perfect storm that accelerates the use of solar power everywhere.