Watch out, microinverter startups, a big player has just joined the game.SMA Solar Technology

, the world's largest inverter maker, has bought the microinverter technology from OKE-Services, a developer of electronics for photovoltaic systems based in the Netherlands, SMA said Thursday. The companies declined to disclose the price.

The acquisition would change the dynamics of the microinverter field, which has attracted a growing number of startup companies including Enphase Energy, Enecsys and SolarBridge Technologies (see list).

"It's a absolute threat to startups. SMA has validated the market," said Eric Wesoff, a senior analyst with GTM Research. "Enphase is doing an amazing job, but people would probably rather buy from an established public company."

Microinverters are the miniature version of the traditional inverter that converts the direct current generated by solar panels into alternating current fit for use onsite or for feeding the electric grid.

A solar energy system could make use of a centralized inverter, which comes in a box located close to the panels. A microinverter, on the other hand, is attached to each panel.

A centralized inverter uses what's called the maximum power point tracking (MPPT) algorithm to determine the optimal power output for the entire system. Because the solar panels are typically connected in series, one poor-performing panel could affect the output of the others.

The MPPT could be lowered even if only some of the panels are shaded by trees or buildings, for example. A lower MPPT would result in lower power output by the system.

A microinverter does the MPPT for each panel instead of the entire system. So using it could ensure that a few poor performing panels won't drag down the output of the others.

But critics say microinverters aren't sturdy enough, and replacing them just adds costs.

The concept of microinverters isn't new. SMA thought about developing microinverters about 10 years ago, but decided against it. Since then, other companies have improved the hardware and software to make microinverters attractive.

Enphase, based in Petaluma, Calif., began commercial production last year and has sold "tens of thousands" of them since. Back in May, the company said it had raised $22.5 million from investors including Madrone Capital Partners, Bay Partners and Third Point Ventures.

With the growth of the solar energy market, microinverters could find a wider acceptance. Jumping into this new line of business now rather than later is a good move by the SMA.

"I think it's a game changer. We have the money to all the research we need to do and marketing," said Jeff Kosiniski, business development manager for SMA America.

OKE, founded in 1984, is one of the early developers of microinverters. The company has more than 15 years of developing and making microinverters, SMA said. SMA plans to take OKE's technology and develop its own line of products.