Survey reveals customers' wish list for PV inverter improvements

System-level monitoring, continued adoption of string inverters for large PV installs, and improvements by Chinese suppliers are among the trends gleaned from a survey of inverter buyers & sellers.

In a survey conducted in 4Q11, IMS Research asked more than 400 PV installers, distributors, and engineering/procurement/construction (EPC) firms about their purchasing habits for solar inverters: brand and product preference, product features, microinverters and power optimizers, service/warranty, and pricing, and what customers want to see improved in inverter technology. The survey covered several major global markets, with responses parsed by country and customer type.
Among the key findings from the survey results:

• Western inverter suppliers are still clearly favored, and market-leader SMA in particular has great brand affinity. But nearly 30 percent of respondents, with an emphasis on Europe (Italy and the UK in particular), indicated they think Chinese products are of "acceptable quality."

• Survey respondents still see room for improvements. For string inverters, they want more MPPT channels and a wider MPP range; for central inverters it's improved system monitoring and fault detection, noted report co-author Cormac Gilligan.

• Also gleaned from the survey: continued adoption of three-phase string inverters for large PV installations. More than 70 percent of respondents said they would consider using a string inverter in >750kW systems, and 30 percent said they'd use them in megawatt-sized projects.

• System-level monitoring is a hot topic. Nearly 70 percent of respondents said they want monitoring diagnostics down to the string level, and 15 percent want the ability for individual panels. That points to an opportunity for firms in offering panel-level electronics, says IMS Research senior research director Ash Sharma. Only 1 percent of PV installations in 2011 used microinverters, but more than 10 percent of survey respondents "are intending to use microinverters for some of their projects in the next 12-24 months, with an even greater number wanting to use DC-DC power optimizers," he says. Still, more than half of respondents cite higher costs for microinverters and hesitation to adopt what they see as an "unproven" technology.

• Even though inverter pricing is expected to fall by 20 percent or even 30 percent over the next three years, "nearly all" expect inverters to incorporate more and improved features and better quality. (More than half, though, indicated they'd pay a premium for just a 1 percent yield gain.) This sentiment is most likely due to customers determining their preferred inverter price based on their overall system budget. "With module and system prices falling rapidly, this inherently puts more pressure on inverter prices to fall too," Gilligan said.