At the federal level, the IRS's Investment Tax Credit (ITC) is still considered the big dog among incentive programs for using renewable energy. While not specific to renewable energy, the ITC offers companies a 30% tax credit for renewable power investments.
Just seven years ago, deploying a one-megawatt solar array was considered a huge accomplishment. Companies today, however, are regularly deploying systems that 100 times larger, according to the Shugar.
For example, Apple last year completed a 100-megawatt solar farm for its North Carolina data center. A fuel cell facility capable of storing five megawatts of electricity will support the solar farms.
At full capacity, Apple's data center will draw about 20 megawatts of power.
"While we'll produce 60% of the power used by our Maiden data center onsite, we'll meet the remaining 40% of our energy needs by directly purchasing clean, renewable energy generated by local and regional sources," said Apple spokesman Nick Leahy.
Apple rival Microsoft is one of the largest purchasers of green power in the U.S. The EPA recently recognized it as the third largest purchaser of green power in the U.S., buying up more than 1.1 billion kilowatt-hours of green power a year.
Microsoft has been dabbling in renewable energy for more than a decade.
In 2004, it installed what at the time was Silicon Valley's largest solar power system, which produced 480 kilowatts at peak capacity. The solar farm was composed of 2,288 tiles, and today offsets as much as 15% of Microsoft's energy needs at a five-building campus with about 1,800 workers, according to Microsoft spokesman Doug Free.
An engineer inspects solar panels in Apple's Maiden, N.C. solar power array (source: Apple)
The company is now exploring using biogas from landfills to power its facilities. Last fall, Microsoft's Global Foundation Services Group, which runs the company's cloud services and data centers, unveiled a data center that will run on biogas produced by a local Wyoming landfill and water treatment facility. The "mini-data center" will use 200 kilowatts coming from the biogas facilities, said Henretig.
But Microsoft's largest investment has been in hydroelectric energy because the company's headquarters, and 60% of its operations, is located in the Puget Sound region of Washington state.
About 46% of the energy used by Microsoft's Redmond, Wash., campus comes from hydroelectricity, and most of the power for its data center in Quincy, Wash. is from hydropower generated in the Columbia River Basin. That alone put Microsoft in the No. 3 spot on the EPA's top 50 green companies in 2012.
At the top of the list was Intel. Officials there declined to speak about Intel's renewable energy program.
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