Last week, Facebook became the latest IT company to install photovoltaics at a data center. It follows other IT companies like Google, Amazon, Yahoo and Microsoft, all of which are using solar and renewables to varying degrees.

Still, Greenpeace is stepping up pressure on Facebook to use more renewables and reduce its dependence on electricity sourced from coal-fired power plants.

The company said it is in the testing phase of understanding how photovoltaics will work with its data centers.

“We started the solar project as an opportunity to learn how to integrate onsite renewable energy sources into the complex operating sequences found in data centers,” said Jonny Thaw, a spokesperson with Facebook’s Open Compute Project.

The company will take the lessons learned from this first solar installation to guide future decisions regarding onsite renewable energy generation, particularly solar, he said.

Facebook officially unveiled a 100-kilowatt photovoltaic array on April15 at its new Prineville, Ore., data center, to help offset its energy use.

The system will mainly support office functions at the datacenter.

“In the data center world, 100-kilowatts isn’t much power. By the time the facility is complete, it will be measured in dozens of megawatts of electricity,” said Data Center Knowledge.

“I think it’s an encouraging sign in the bigger scheme of things. In many ways these companies need to get comfortable with any investment in renewable energy. These big data centers are some of the largest energy demand [centers],” said Casey Harrell, an IT analyst with Greenpeace. “We’re making sure they’re plugging in as much as renewable energy as possible.”

“They’ve made some unfortunate decisions, but we see nibbling like this and see there is value here. That should hopefully lead them to do much more at the scale we’re talking about with Google,” Harrell said.

Greenpeace is focusing on Facebook much like it focused on Apple Inc. a few years ago.

“I think that’s a fair assessment,” Harrell said.

The organization ran a campaign protesting Apple’s use of hazardous materials and calling for it to recycle more of its waste. Ultimately, the company responded by developing a comprehensive recycling program and eliminating most hazardous materials from its products.

“Our team is limited in terms of size. We need to take a company that has built its reputation on transformative change. We want to see who has the capital now and has a brand being associated with being transformative, and say, ‘Why don’t you be part of the energy revolution?’” Harrell said. “We’re trying to be encouraging. We’re working with them to try to be solutions oriented.”

It appears that Facebook is on that track.

“Being green is important to us,” Thaw said.

The company recently announced its Open Compute Project, which it said has made its servers 38 percent more efficient than the EPA standard for state-of-the-art data centers and 24 percent less expensive to operate.

The company also said its efficiency efforts have allowed it to cut energy consumption by 2.42 million kilowatt hours annually, reducing its greenhouse gas emissions by 967 metric tons.

“As Facebook grows, we'll continue to invest more in reducing our impact on the environment and sharing more of the efficiency technology we've developed,” Thaw said.