New Hampshire, USA — Back when silicon prices were north of $400/kg, finding ways to use less material was seen as a keen opportunity, from different formfactors to thinner wafers. One group of efforts centered on “upgraded metallurgical-grade” (UMG) silicon, which was essentially a grade of silicon slightly less than the ultrapurity required by the electronics industry. Those efforts broadly lost their appeal, though, once silicon prices plunged to $20/kg and below, though prices have started showing signs of rising slightly.
Nevertheless, solar manufacturers still need to keep finding ways to reduce costs, and silicon remains the highest cost input into the module manufacturing process. This is why Silicor (née Calisolar, until a 2012 name-change), which itself has had some bumps along the way, is still plugging along, adding $6 million more in funding last week and bringing in a heavy-hitter investment banker to start raising a lot more.
Silicor’s solar silicon-making process involves dissolving ~97-percent-pure metallurgical-grade silicon into an aluminum smelt; from the combined liquid alloy the silicon hardens first and the aluminum is poured out. (This is separately marketed as a “master alloy” additive that hardens other aluminum metal-based components such as auto engine parts.) Most of the remaining aluminum on the silicon flakes is removed by an acid bath and drained out. (That liquid, polyaluminum chloride, is resold to wastewater treatment facilities as a coagulant for purification.) The leftover flakes are then melted and cooled again to skim off the last of the aluminum, leaving the solar silicon with what is claimed to be over 99.9999 percent purity. Wafers and cells made from Silicor’s material are said to average 16.5 percent conversion efficiency, with champion cells exceeding 18 percent.
The company’s proprietary process can produce silicon at around $9/kg as a “drop-in” replacement for electronic-grade silicon, according to Silicor CFO John Beaver, in an e-mail exchange. In a very crowded silicon materials market with GCL, OCI, REC, Hemlock and Wacker, “we will compete initially on price,” he said. Their process is also claimed to use roughly half the energy of the traditional Siemens method of making silicon.
Silicor has raised about $250 million of debt and equity, most of it (and all of this latest round) coming from longtime backer Hudson Clean Energy Partners, Beaver confirmed. Bringing in Baird now “will allow Silicor to reach a number of potential investors, more than the company can reach on its own,” he said.
Beaver also provided an update on the company’s proposed Mississippi manufacturing plant, which originally was on the drawing board as a 16,000 MT production site at a cost of $600 million in Lowndes County with nearly $100 million in local incentives, and much of that output promised to Suntech. Earlier this year, however, the company started looking elsewhere, and Beaver confirmed the company is pursuing a site in an adjacent county to Lowndes. They’re also exploring international sites for a large-scale silicon facility, depending on availability of financing, electricity availability and cost, and available skilled workforce.
[Update 9/18: CFO John Beaver says this is now 17.3 percent average conversion efficiency with champion cells exceeding 18.5 percent. The company made 25 million solar cells between early 2010 and late 2012, all of which have been sold and turned into modules. And the company’s facility in Ontario has been “mothballed” to focus on building out the new one.]
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