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Transphorm and Enphase team up on solar power conversion

Figuring out ways to convert solar power more efficiently is starting to attract significant public and private dollars these days. Google-backed (s goog) Transphorm is teaming up with another startup, Enphase Energy, to develop a solar power conversion device using financial support from the Department of Energy’s ARPA-E program.

The project is set to get $3.64 million from ARPA-E and is one of 60 projects that the DOE announced on Thursday. Transphorm and Enphase will develop a solar inverter using the semiconductor material gallium-nitride. Here’s the project description:

Transphorm will develop a robust, cost effective, high efficiency power transforming device that will be integrated into solar panels. This technology is based on innovative high performance architecture, called a four quadrant switch, enabling a single semiconductor device to switch voltage and current in both directions. It will be made with an advanced semiconductor device material, Gallium Nitride (GaN). The four quadrant design will result in reduced losses and higher efficiency. This “plug-n-use” technology will enable reliable power transfer from solar panels to the grid and revolutionize photovoltaic deployment in commercial establishments and solar farms.

Transphorm and Enphase make an interesting pair. Transphorm made its public debut at Google Ventures’ office in February of this year and claimed its gallium-nitride device can significantly limit power losses that happen when the direct current produced by solar panels is converted to alternating current to feed the grid.

Enphase Energy, meanwhile, has made its name by developing power conversion electronics called microinverters. Each microinverter goes on the back of a solar panel to do the DC-to-AC conversion, and it disrupts the conventional design of pairing an inverter with a bunch of solar panels (this type of inverter is larger and sits in a box next to a solar array). In June this year, the venture-backed Enphase filed for an initial public offering.

Transphorm wants to use gallium nitride to replace silicon, the material commonly used in inverters today. Transphorm executives said silicon has reached its limit in increasing power conversion efficiency, so it’s time to turn to alternative materials.

I asked Enphase’s CEO, Paul Nahi, about Transphorm’s technology a month after Transphorm’s coming-out party. Nahi was circumspect when he dubbed Transphorm’s technology “very interesting” and said Enphase was investigating the use of silicon alternatives as well. He added, “It will be a while before (gallium-nitride devices) can reach volumes and the right price point.”

Improving solar power conversion is a hot field. ARPA-E has created a research program devoted to this field, and its Thursday funding announcement included six other projects. SolarBridge Technologies and Satcon Technology are among the grant recipients.

Power conversion technology has many uses beyond solar, so a startup that can create novel and affordable technology will be able to sell it to many markets, such as data centers and electric cars. In fact, Transphorm caught Google’s attention partly because the startup’s technology could lead to big energy savings for data center operators.

Transphorm isn’t alone in developing an innovative approach. A new venture-backed startup, Array Converter, which we also wrote about on Thursday, is working on a device to use radio wave to carry out the power conversion.

Photo courtesy of Enphase Energy

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