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

Ucilia Wang, Contributing Editor
June 06, 2011 | 12 Comments

Enphase Energy launches its third-generation microinverter today. The company hopes this will keep it ahead of its competitors in an increasingly crowded market.

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.

12 Comments

Kevin Wang
June 20, 2011

To gary-tulie-73445:

Yes I also think the product is quite interesting, and the most fascinating thing is that Aerofortis claim even with 1-2 panels of the 4 panels not working, you can still have constant 400VDC output, unlike in conventional string connection. I think I will test the DPC and see how it performs.

Ray Boggs
June 20, 2011

'The only problem with products like SolarEdge are you still rely on a single point of potential failure' We've been a factory authorized inverter repair center for over 10 years and have a lot of experience repairing inverters at the component level not just board swapping. One thing I know to be true is that circuit simplicity is the key to reliability. With multiple microinverters you not only have a more complex device with a higher parts count attached to each module but now you're dealing with far more potential points of failure. Enphase may offer a 25 year warranty but somebody will have to pay an installer to replace those inverters once they've failed because the warranty does not cover product replacement labor. That somebody obviously will be the homeowner. 40 micro inverters means the potential for 40 paid potential service calls over the product's 25 year warranty period.

SolarEdge's power optimizers have a much lower parts count which potentially make for a more reliable device. Also when you consider SolarEdge's lower system cost per Watt, higher wattage capacity per solar module, higher rebate per Watt and the highest 97.5% CEC weighted efficiency rating for any 240 volt single phase inverter for a higher potential power yield, SolarEdge's increased savings and yield will probably pay for that replacement inverter down the road anyway. Keep in mind that many customers are installing solar modules with a higher output rating than what these Enphase inverters are rated for. Search the Internet and you'll find consumers who are questioning why they installed 230 watt or larger modules on M190 inverters, only to have the potential power from their 230 Watt modules maxed out by their microinverters at 199 watts. With SolarEdge you get a full 250 Watts or 350 Watts of inverter capacity per module. There's no compromise. Again I am sold on SolarEdge. After 13 years in this business, it's what we're going to install on our new sales office.

Gary Tulie
June 20, 2011

Thanks for the link, the aerofortis product looks very interesting as a way of maximising yield and easing design constraints.

The product uses a DC to DC converter which as you say manages 4 panels with maximum power point tracking. Several strings can be combined onto a central inverter which receives a constant voltage input. The inverter does not itself have to contain a maximum power point tracker, so can be of simpler lower cost design.

As strings are short, and independently managed, it does not matter if each string has a different orientation, or if the panels are a different size or from a different manufacturer, so eliminating much of the complexity of array design and reducing concerns regarding array losses with partial shading or panel mismatch.

Kevin Wang
June 20, 2011

I attended the Intersolar in Munich earlier this month and I came across a Taiwanese company that provides micro-inverter similar to Solaredge and Enphase. However, their product called DPC connects to 4 panels instead of 1, and the output becomes 400VDC. They claim to increase the efficiency by 10%, has anyone heard of such product? Their website is www.aerofortis.com.

ANONYMOUS
June 8, 2011

The only problem with products like SolarEdge are you still rely on a single point of potential failure in the central inverter used, and it only includes a 12 year warranty. It's great to save some money up front, but what happens in 12.5 years when it goes out and needs to be replaced at a cost higher than the difference between a central inverter and micro-inverter? For small residental systems, the Enphase system can't be beat. The article from June 2 shows a study of Enphase being much more reliable than central inverters. I've sold both, and now I only sell Enphase.

Sam Harriman
June 8, 2011

Yes,
Reliability is clutch. That's one thing i like about the enphase product—especially now that their enlighten monitoring package comes free. Isolating and trouble-shooting faulty array components is a breeze when there is a performance record for each individual module. We quickly identified a faulty SolarWorld module in one of our first Enphase installations out here in Portland, OR. The irony of the situation: it was on a system we had installed for a SolarWorld executive! ;D We were able to bring a spare module from our shop to the client's house, hop up on the roof (it was a 16/12 A-Frame so we had to, ya know, know what we were doing up there) and have the issue resolved in a couple hours. Like i said, bravo Enphase.

SolarWorld, of course, shipped a replacement module in a matter of days. Enphase doesn't pay me anything, but i know why they're product is worth more in the market place. And now that their warranty exactly equals a standard module warranty, it's a slam-dunk.

Gary Tulie
June 8, 2011

With micro-inverters, the biggest area for caution is reliability. While I would not wish to discourage their use or champion any one brand, a micro-inverter - even for domestic use has to be reliable for around 25 years whilst exposed frequently to high temperatures, possibly up to 90C for on roof and 110C for in roof arrays - harsh conditions for any electronics. The cost of identifying a failing inverter, getting up on the roof, getting to and lifting the affected panel and replacing the inverter will be very high, so lack of reliability will carry a large cost penalty - only part of which (the cost of a replacement inverter) is likely to be covered by any inverter warranty.

Sam Harriman
June 7, 2011

Bravo! Enphase makes good stuff. I spec their micro-inverters all the time up here in Oregon. Their product line, and customer service, is quite good. I look forward to milking more power out of high-power 60-cell modules with STC DC output over 230W.

Dave Merrill
June 7, 2011

I echo your thoughts on the welcoming of competition. I have installed (12) Enphase systems - mostly small 1.5 Kw school systems - and find them economical on a small, 7 module arrays.

I have also just installed a larger 6 Kw Solar Edge system and find it superior in many important ways (cost, safety, ease of installation and the better efficiency...).

Ray Boggs
June 7, 2011

I'm still sold on SolarEdge with its much higher 97.5% CEC weighted efficiency, individual module monitoring, shade mitigation, communications over the DC lines rather than the noisy AC lines, higher powerbox capacity,(250 Watts versus Enphase's 215 Watts) and lower price per Watt.

Ucilia Wang
June 6, 2011

@theBike: you are right, the cabling method is Enphase's own design and meant to be sold as part of its microinverter/monitoring service. I've added a line in the story to make it clear.

kent beuchert
June 6, 2011

Now we can finally see some competition in this field, which has been controlled by Enphase as a monopoly until now. Note that Enphase never produced 25 year quality inverters until competitors did so, although the technology to do so jhas been
known for years. Also we will undoubtedly see some price discounts now. Enphase was pricing its converters about double their value. I have suspicians about "new cabling methods" which sounds like something proprietary, used to lock the user into using only Enphase converters. That is a typical company strategy
to reduce consumer choices, raise prices and eliminate competitors. Unfortunately for Enphase, no one looks to them as leaders anymore and everyone is eager to switch to one of its many competitors offering better products.

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Ucilia Wang

Ucilia Wang is a California-based freelance journalist who writes about renewable energy. She previously was the associate editor at Greentech Media and a staff writer covering the semiconductor industry at Red Herring. In addition to Renewable...