Business for a Better World: Solectria building specialty parts for solar arrays

With the nation's growing focus on clean energy sources, Miguel Carrillo realizes the importance of his role at Yaskawa America's Solectria manufacturing facility in Buffalo Grove.

Carillo is a production supervisor at the 140,000-square-foot plant located at 1067 Johnson Drive, which makes, among other things, string inverters for business and commercial solar arrays.

In other words, the facility's products convert the sun's rays into energy that's usable by the electrical grid.

"I came here specifically for the photovoltaic line," Carrillo said. "It's a very unique product, and the people who work on this particular line were selected into the process because of their ingenuity, their charisma and their approach to building these units.

"The people who work on these lines have a lot of pride in their product. They are building a sustainability product."

According to Craig Espevik, Yaskawa America vice president for operations, the Buffalo Grove Solectria facility began manufacturing the company's XGI-1500 string inverter about three years ago.

A string inverter plays perhaps the most critical role in a solar array that might be found on the top of a large retail location or in at your garden-variety solar farm you might see in the middle of a desert. The collection panels that collect the sunlight emits a direct current, or DC, charge, but that can't be used on the electrical grid because power there is alternating current, or an AC charge.

"Our inverters convert the (DC power) to AC and it also phases that power so it blends into the power on the grid," Espevik said. "The grid is a complex mechanism. If you're going to put power on it, the power you put onto it has to dovetail."

A common misperception is that a solar array, including a string inverter, directly powers the building on which it is located. In fact, the DC electrical power harvested from the sun and converted into AC power is placed on the electrical grid, which can power anything. The building owner, in turn, receives credit from the power utility on its monthly bill for the power it generates.

String inverters are rectangular, mounted in on a stand and located in a small enclosure that's about 2 feet wide by 3 feet tall and about 2 feet deep. Since they are almost always located outside, they have to be tough. Espevik said desert conditions are particularly challenging because the inverters go from extreme coldness in the night to the heat of the day, so condensation has to be managed, along with animals like snakes that might try to breach the enclosure.

Mark Goodreau, Yaskawa America's Solectria general manager, said the company's string inverters are sold to companies that develop solar projects, including leasing land or space. They are also sold to Engineering Procurement and Construction companies, or EPCs, which actually install the product.

The Buffalo Grove facility also works in conjunction with another Yaskawa America plant in Oak Creek, Wisconsin, that builds combiner boxes, or wiring boxes that take the power from the solar array and drives it into one cable into the string inverter. Design work for all products is done at Yaskawa America's Solectria headquarters in Lawrence, Massachusetts.

Pardon the pun, the Espevik thinks the future of solar arrays, especially on the business and commercial side of the business, is bright. This is because the overall cost is coming down, and the roof of a building is the perfect place to collect the sun's rays.

"I think people are finding ways to wake solar, and wind, more cost competitive," said Espevik, who noted that Solectria does not make residential string inverters. "The cost curve has declined at huge rates, and it's much more competitive against gas, steam or nuclear generation."

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