While Google has made a significant dent in its power requirements with renewable energy, green power projects such as the Grand River Dam Authority windmill farm cost more than brown, or polluting, energy resources.
"In places where we're procuring renewable energy through a utility ... we're paying a slight premium for that power, but it's worth it to the company because we've determined that small premium we pay is financially reasonable," Demasi said.
"It's tough to procure renewable energy at equal to or less than what you can buy power off the grid," he continued. "So you've got to have a corporate appetite for that premium. The founders and leaders of the company believe we should do the right thing for the environment. That's definitely a clear mandate."
By pumping money into renewable energy resources, Google also hopes to drive up the economies of scale in order to eventually push prices below that of brown energy resources, Demasi said.
According to the U.S. Energy Information Administration, utility-scale wind projects cost about $2 per watt to install, and solar projects are about $3 per watt. Using those figures, a 100-megawatt wind project would cost about $200 million; a similar solar facility would cost about $300 million.
The median installed price of solar photovoltaics has dropped by 25% to 35% over the past three years, according to a study published by the Lawrence Berkeley National Laboratory in November 2012.
The cost for solar electricity dropped by $2.1 per watt from 2008 through 2011, according to Lawrence Berkeley National Labs.
The study, which includes preliminary data for 2012, included data based on more than 150,000 individual residential, commercial and utility-scale photovoltaic systems, totaling more than 3,000 megawatts and representing 76% of all grid-connected photovoltaic capacity in the U.S.
According to the study, the median installed price in 2011 was $6.1 per watt for systems less than 10 kilowatts in size; $5.6 per watt for systems between 10 and 100 kilowatts in size; and $4.9 per watt for systems offering than 100 kilowatts. Prices for 2012 are not yet available.
But partial data for the first six months of 2012 indicate that prices continue to fall, with the median installed price of projects last year 3% to 7% cheaper than in 2011.