Intersolar wrapped up last week, where inverter manufacturers eagerly showcased new features, new product lines, and even their entrance into the U.S. inverter market. While some conversations focused on increased inverter lead times, most of the buzz was fixated on how new inverter technologies, including micro-inverters, can transform the value and fundamental design of PV installations.
One question in particular stood out: can micro-inverter technology penetrate the growing U.S. utility-scale multi-megawatt PV system market?
During Greentech Media's Utility Growth Opportunities conference, venture capital firm Kleiner Perkins Caufield & Byers, who recently backed Enphase Energy, fired the first volley by asserting that micro-inverters are suitable for MW-scale projects. Aside from Enphase, potential new entrants like Sparq Systems and DirectGrid Technologies are already targeting utilities; the latter is already considering a 1kW unit for new large footprint modules. These micro-inverter companies believe that the fundamental value proposition of increased system harvest is the same from residential systems through multi-megawatt systems and that ultimately, utility owners will not throw away money in the form of precious megawatt-hours.
Although Enphase has sold more than 300,000 units in under two years, centralized inverter manufacturers don't seem fazed. At Greentech's conference, a panel of large-scale inverter manufacturers contended that placing sensitive micro-inverter electronics under the hottest part of a PV system (i.e., the PV module) was a non-starter for utility-scale PV system owners. Instead, Satcon promoted its string-level MPPT Solstice solution, while GE alleged that at the utility scale, good design and quality assurance would eliminate most shading and mismatch concerns. SMA, which recently acquired OKE-Services, and PVPowered, which has partnered with DC-DC optimizers, both stressed that micro-inversion may make sense at the residential and small commercial level, but won't ever threaten centralized inverters at the utility scale.
Discussing micro-inverter reliability, however, seems to be well-worn territory. With millions of operating hours and rising sales, Enphase has certainly convinced many U.S. installers. The bigger challenge for micro-inverters seeking to enter the large commercial and utility market is whether they will be able to provide comprehensive data management and grid support. The consensus amongst centralized inverter companies is that micro-inverters provide too much data granularity: utilities simply don't want to communicate with tens of thousands of units.
Raghu Belur, VP of Marketing at Enphase, retorts, "There is never too much information; you just need to know how to manage it," and points to Google as the prime example of data management. But the question remains whether micro-inverters can provide new utility grid support requirements like low voltage ride-through and reactive power control being pushed by German and pending CAISO regulations.
Regardless, both micro-inverters and centralized inverter technologies will face increased competition in the U.S. market this year as established European inverter manufacturers look to expand their business state-side amidst slowing European subsidies, and as traditional electronic component manufacturers like Siemens and GE look to add solar to their product offerings. Though the U.S. market is on the rise, the inverter space will likely become much more crowded.