Enphase Energy Launches Third-Gen Microinverters with 25-Year Warranty

The California company pairs the microinverter, the M215 Series, with a new cabling system and a 25-year warranty designed to match the lifespan of a solar panel. Enphase previously offered a 15-year warranty. It’s already lined up manufacturers who will attach Enphase’s microinverters onto the back of their solar panels and sell them as integrated products starting in the first half of 2012, said Bill Rossi, chief marketing officer of Enphase.

The company also will no longer charge a recurring fee for its monitoring service, something that it did to recoup the cost of developing the software and providing real-time data about the performance of its microinverters and the solar panels they serve. This change reflects the practice of some of its competitors to not levy any monitoring service charge.

Enphase executives provided an advanced look at the M215 back in March, when they hosted a media day at their headquarters in Petaluma. They touted the improvement of efficiency from 95 percent to 96 percent, which is the highest for microinverters and among the highest for any inverter, according to a list by the California’s solar incentive program.  Efficiencies shown on the list came from tests that used criteria developed by the California Energy Commission (CEC); the benchmark is often referred to as the “CEC weighted efficiency” by solar industry people. Given California is the largest solar market in the country, the list provides a good rundown of what inverters – central inverters or microinverters – are available in the North American market today.

“We are setting the bar for efficiency,” Rossi said. “Every point of efficiency improvement translates into a lot more energy production and a better return on investment for system owners.”

The concept of microinverters isn’t new. Some companies tried to popularize it 10-15 years ago, but they couldn’t develop microinverters that had high enough efficiencies and reliability to compete with central inverters. Microinveters are so called because each of them is responsible for converting the direct current (DC) from a solar panel into alternating current (AC). Each central inverter does the job for a whole bunch of panels.

Microinverter’s big selling point is its ability to calibrate and ensure the optimal energy output of each solar panel. A central inverter can do that, too, but because it is in charge of a bunch of solar panels, its calculations are influenced by the lowest-performing panels. If an array is partly in the shade, for example, then the optimal energy output of that entire array will be more on par with the output of the lower performing panels.

The new Enphase, M215 microinverter is designed for a solar panel that can produce up to 230 watts of DC power or 225 watts of AC power (the “215” in the name refers to the average AC power that the microinverter can support), Rossi said. The new cabling system, which Enphase designed to sell as part of its microinverter hardware and softare bundle, is set up to eliminate some bulk and speed up the installation time.

Microinverters have a way to go to compete in price, however. In the past, Enphase executives said their products commanded a 15 percent premium over central inverters for a same-size array. That difference can be twice of that, Rossi said, and depend on whom installers buy the microinverters from. Enphase sells its products to distributors and some installers. Microinverters are largely used in residential and small commercial installations.

Enphase, founded in 2006, has led the microinverter market so far. The company launched its first product in mid-2008 and has since shipped over 750,000 of them. Established inverter makers naturally weren’t optimistic about Enphase’s chance of winning over customers, having remembered the last time some of them tried to carve out a market for microinverters.

Enphase’s fortune has risen along with the growth of the U.S. market, where federal and state incentives have boosted consumers’ interest in solar. In February, Siemens announced it will start selling Enphase’s microinverters through its U.S. distribution network. Siemens is carrying the product and related software and cabling system under its own brand.

Enphase may have led the way in the microinverter business, but it’s now being chased by a growing number of competitors, including Enecsys, Direct Grid, SolarBridge Technologies, and Power-One. Power-One, mainly a central inverter maker, presents a particular threat to Enphase because Power-One is among the top three inverter makers worldwide and therefore already has an established network of distributors and customers in key solar countries. The company announced the launch of its microinverter only last month.

Competition is going to heat up when the world’s largest inverter maker, SMA Solar Technology, launches a microinverter. The company bought a microinverter technology from OKE-Services in 2009. It has stayed mum about when it will start selling microinverters. Dave Wojciechowski, senior director of sales for SMA’s American operation, told me in April that the company saw microinverters as a niche market product and for residential installations only, but that the company planned to introduce a product “shortly.”

Enphase is now eager to conquer the European market, where it will perhaps face even more skepticism from installers; many of them have been in the business for far longer than many U.S. installers and are set in their preferences for central inverters. The company plans to start shipping products to Europe later this year, Rossi said.