San Francisco — The vertical extension of SunPower’s towering corporate structure with the November 10 addition of SolarBridge’s AC inverters signifies one defining feature for the half dozen solar companies that will survive in the future.
The move has been acclaimed for its expected help in building SunPower’s residential business, since statistics for first quarter 2014 indicate more MWs of PV were installed in residential systems than in commercial systems since 2010. The acquisition was also praised for being an investment aimed at bringing more downstream electronics into the panel, and for being a panel development improvement outside of traditional research directions.
But of perhaps of greater significance to the residential solar industry as a whole is the soft cost savings advantage of the SolarBridge TRUEAC system, which the manufacturer announced in a study, on October 15, with a cost savings of 33 percent over string inverters, according to Bryan Thomas, SolarBridge’s director of product management, and the author of the study.
The SolarBridge study goal was to build on recent balance of system soft cost analysis by Rocky Mountain Institute and Georgia Tech Research Institute, which compared soft costs in the United States to those in Germany. That analysis revealed that German costs are 73 percent lower than those in the United States.
But since the RMI and similar U.S. National Renewable Energy Laboratory (NREL) focused only on string inverters for the basis of their comparison, SolarBridge did its own survey, also comparing the cost when SolarBridge TRUEAC modules were used, when detached microinverters were used, and when a combination of string inverters and DC optimizers were used.
SolarBridge surveyed “32 installers in 16 key solar states across the country” and found that “for an average 5 kW residential system, TRUEAC module use reduced total labor costs by 33 percent compared to a string inverter, as well as by 35 percent compared to an Enphase detached microinverter, and by 48 percent compared to a SolarEdge power optimizers,” according to Bryan Thomas, SolarBridge’s director of product management.
Employing a team of four — including two non-electricians and two electricians — the average installation time for a string inverter based residential system is 2.4 days, the study indicates. Survey respondents with relevant experience said using SolarBridge TRUEAC modules reduced their installation time by an average of 24 percent compared to using string inverters in the same installation, it concludes.
SunPower had already utilized SolarBridge’s AC inverters for several years prior to the acquisition, and now the AC inverters are expected to be tailored to the former’s top-of-the-line X-Series residential panels.