San Jose, California-based SoloPower – a manufacturer of flexible, thin-film solar photovoltaic (PV) cells and modules for rooftop applications – has raised another $43.7 million in an equity round this month, according to a new SEC (News - Alert) filing. Investors in the round include Greentech Capital Advisors of New York City and Thomas Weisel Partners of San Francisco.

The five-year-old company uses Copper-Indium-Gallium-Selenide (CIGS) and a proprietary roll-to-roll electroplating process to manufacture its flexible solar panels – a technique it has claimed will keep the costs of its products competitive versus other technologies on the market.

In addition, this technology is lighter-weight and suppler, compared to polycrystalline silicon cell solar equipment. It can be installed in where more rigid, heavier options won’t work.

In February, SoloPower locked in a $197 million loan guarantee from the U.S. Department of Energy (DOE) Loan Programs Office to retrofit a facility in Wilsonville, Oregon, “ that, when completed and at full capacity, is expected to produce approximately 400MW of thin-film PV modules annually,” according to a company press statement.  The company expects to spend a total of $364 million on building the plant, and to employ about 500 people, full-time, once the facility is running at full capacity.

“SoloPower’s lightweight, flexible, CIGS modules represent a true breakthrough in the solar industry,” said Tim Harris, CEO of SoloPower. “The SFX1-i3 lightweight module is optimized for commercial and industrial roofs, allowing our customers to increase their profitability and to complete projects that would not have been possible with other technologies.”

While SoloPower has attracted a lot of cash and support, it faces stiff competition from Chinese manufacturers like Suntech Solar and Trina Solar, Germany’s Q-Cell, and U.S. companies like First Solar, also in the thin-film game.

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