SoloPower shoots for another $44M for thin film solar

Solar thin-film startup SoloPower has been raising money in earnest in order to set up a factory to mass produce its panels. And now the Silicon Valley company is aiming for a $43.75 million round and has so far lined up about $15 million, according to a filing Wednesday.

The company develops solar panels using copper, indium, gallium and selenium (CIGS) instead of conventional silicon to convert sunlight into electricity. SoloPower is among a cadre of CIGS solar panel manufacturers who have completed product development and either have recently started or planned to begin mass production within the next year or two. Its peers include Stion, Solyndra, MiaSole, Sulfurcell and Nanosolar. Q-Cells, based in Germany, also is a competitor and announced on Wednesday it has started selling its CIGS panels in North America.

SoloPower, which began raising the new equity round earlier this month, has been busy persuading investors that it’s a good bet. In March this year, it had raised about $13.5 million in equity while gunning for $20 million, according to another filing. In January this year, it also raised a $51.58 million round by selling equity and rights to buy shares later.

The company will need ample cash to build its first commercial-scale factory and boost sales and marketing efforts. It has a pilot line that could produce 10 MW of solar panels as of last fall, and company CEO Tim Harris told us then that the company was planning to add 75 MW within a year. That 75MW line turned out to be part of a plan to build a 300 MW manufacturing center in Oregon.

Soon after announcing its 300 MW manufacturing plan, the company received a loan guarantee offer of $197 million from the U.S. Department of Energy. In its announcement about the loan guarantee offer, SoloPower said it was planning a bigger, 400 MW factory in Oregon instead. The loan guarantee will help the company secure about 54 percent of the $364 million project cost, according to the DOE website. SoloPower has until Sept. 30 this year to finalize the loan guarantee and start construction.

Getting to market

SoloPower launched a set of flexible CIGS solar panels last year. Instead of using glass to protect the solar cells from moisture, flexible panels use special polymer materials to encase the cells. Flexible solar panels are lightweight and can be built into roofing materials. But since glass is such a solid protective material, many CIGS solar panel manufacturers have opted to use glass instead of the newer and more expensive polymer materials.

However, roofing materials with built-in solar cells haven’t taken off in the market yet. The vast majority of the solar panels, regardless of whether they use CIGS or silicon solar cells, are mounted on the rooftop or on the ground.

SoloPower and other CIGS manufacturers do hope that flexible panels will eventually become more popular and allow them to better differentiate their products from silicon solar panels. Silicon solar cells are thicker and more rigid, so they can’t turn into the kind of thin and flexible panels that CIGS solar cells can. But silicon solar cells can convert sunlight into electricity more efficiently.

CIGS solar panels, on the other hand, these days generally convert 10-12 percent of sunlight into electricity while silicon solar panels’ efficiencies are several percentage points higher. Q-Cells said its CIGS panels can do 13 percent.  The most efficient line of silicon solar panels can do 20 percent and come from SunPower (s SPWRA).

Photo courtesy of SoloPower