There are two main markets for high quality silicon these days, photovoltaics and computer chips. Luckily there’s enough silicon to go around for both uses. And Intel Corp. a leading computer-chip maker, knows the value of silicon for both purposes. The company recently completed construction on photovoltaic installations at nine facilities.

Intel’s also, according to the Environmental Protection Agency, the nation’s largest voluntary purchaser of renewable energy credits. And it increased its 2011 purchase of energy credits by 75 percent over its 2010 purchase.

Intel’s Director of Global Utilities and Infrastructure Marty Sedler said the company completed the installation of about 3 megawatts of photovoltaics at eight facilities in the U.S. and one in Israel. The U.S. facilities are located in Arizona, California, New Mexico and Oregon.

“We just completed these projects. In addition, we’re looking to take a second whack at the portfolio to put in solar projects,” he said.

In all, the photovoltaic arrays are expected to produce 3.8 million kilowatt hours annually. The photovoltaics represent much less than a drop in the bucket in Intel’s overall purchase of renewable energy—slightly more than a tenth of a percent, actually. The company’s overall purchase of renewable-energy credits in 2011 will total 2.5 billion kilowatt hours. That’s an expected 85 percent of the company’s total electric usage in the U.S. in 2011.

But it’s not feasible for most of the company’s power to come from solar.

“The problem with solar being a big percent [of the power used] is there are a lot constraints,” Sedler said.

Installing solar on large roofs involves making sure the roofs can handle the additional weight. He also said the space requirements for solar was a limiting factor for Intel. For instance, according to Sedler, even the six-acre, 1-megawatt photovoltaic installation the company installed at its Folsom, Calif., location only produces a small fraction of the power used at the facility.

The limitations of solar were part of the reason that Intel installed solar at so many different locations, according to Sedler. The U.S.-based installations were installed under contract with SolarCity. But Intel “Gave a lot of latitude to the installer,” he said.

The installers, he said, were able to choose which panels were the best for each location.

Regarding the company’s commitment to renewable energy, it goes further than just solar, Sedler explained. In its renewable-energy-credit contracts, the company set minimums for each type of renewable energy technology including solar, wind, biomass, geothermal and low-impact hydro.

“We wanted to be technology agnostic,” he said. He could not disclose how much power would come from each source. “It’s a confidentiality issue. Wind will be much higher than solar.”

He explained that there aren’t many solar-based renewable energy credits available on the market at this point—not yet anyway.

Pictured: A mockup of the Folsom, Calif., site, courtesy of Intel.