Micro inverters have quickly become mainstream on solar panel home installations. The idea is simple: you change the DC power to AC power right at each individual module, so you no longer need a central inverter. Enphase Energy brought the micro inverter to market the quickest, but now competitors are cropping up left and right. Installers and consumers seem to like the fact that you don't have to work with high voltage DC power and Enphase has reportedly captured 13% of the small scale solar home market. A number of competitors, including Petra Solar, SolarBridge, Enecys, Sunsil, GreenRay, are bringing their products to market, trying to catch up in this quickly expanding market.
In a recent report, Renewable Energy World summarizes the many advantages of micro inverters:
Micro-inverters are not new, but advances in electronic components have made them commercially viable for the first time, enabling manufacturers to penetrate lower-end markets while addressing some of the challenges associated with standard central inverters. A distributed approach to inverter technology reduces the effect of dust, debris and shade on the array. As the modules are installed in parallel via the AC connection only, any issues with a single module no longer disrupt the rest of the array as had occurred in previous designs using a central inverter. As a result, the solar installation is no longer subject to the 'Christmas light' effect in which shading or failure of a single module affected an entire string.
Based on these advantages, it should come as not surprise that Enphase is quickly being challenged in the marketplace for micro inverters. As reported in Renewable Energy World, "The Enphase foray into micro-inverters has reignited interest in the sector, with several companies about to offer commercially available devices." SolarBridge Technologies earlier this month announced "a complete microinverter solution that enables the industry's first integrated AC modules with a full 25-year warranty." And just yesterday, the Kansas City Star reported that Petra Solar, which is known for its smart pole mounted solar power systems, has unveiled its SunWave Smart Energy Module. According to the report, "Unlike conventional micro inverters, which primarily implement a maximum power point tracking (MPPT) algorithm and comply with the UL1741 grid-tie requirements, the new SunWave SEM incorporates many advanced smart grid and microgrid capabilities."
Enphase is not sitting on its hands or waiting for these competitors to overtake it in the marketplace. Enphase recently announced its fourth generation of micro inverters, introducing a new platform, According to the Company, this new generation of micro inverters achieves 96% efficiency.
How many of these new companies' products can the solar market absorb? Eric Wesoff at Greentechmedia is skeptical, contending that there are simply too many micro inverter companies for the solar industry to support. In an article entitled "Microinverter and Solar Electronics Bubble Soon to Burst," he argues that "20 VC-funded distributed electronics startups is too many for the market to bear." According to his commentary,
The concept of distributed electronics, whether DC or AC, has been accepted in the marketplace. The innovators, entrepreneurs and their investors have essentially created a new market sector. . .But now that the concept has broken through, we have a market developing multiple sources with soon-to-be standardized attributes. Critically, the idea of an AC module subsumes the electronic device's brand and makes it a support component and no longer a stand-alone product. And if the performance and reliability meet spec, then the differentiator becomes price more than anything else -- with vendors at the mercy of the solar module manufacturers...In other words, these products are undergoing rapid commoditization ...The race is on now to scale large, win print position on as many designs as possible, and buckle down for a bit of a price war. The end result is good for the consumer but will be painful -- and likely fatal -- for all but a few of the players in this market.
Wesoff concludes that: "The solar electronics/balance-of-system startup bubble is currently in full-inflation mode, en route to bursting." The market for micro inverters seems to be on target to overtake central inverters on residential PV installations. We will see which of the micro inverter companies will still be in the market in a couple of years.