Greenpeace says it is targeting Facebook employees in a renewed campaignthat is urging the world's most successful social networking site to lead an energy revolution.
A local television advert broadcast on Wednesday in Silicon Valley, where many of the company's 2,000 employees live, will urgne the company to "Unfriend Coal".
Since its launch last year, 680,000 people have joined the campaign, which calls on Facebook to stop powering its penergy intensive business with energy from suppliers that use coal by 2021.
Campiagners also want the firm to disclose its carbon footprint and to act as advocates for clean energy.
The environmental group aims to foster change from within by reaching out to Facebook staff, drawing parallels with the role played recently by Facebook in democracy movements sweeping across the Middle East.
Casey Harrell, senior campaign specialist in Greenpeace's San Francisco office, said: "We love Facebook. Its employees are young and share a lot of our values; they want the world to be a better place. But Greenpeace is saying to Facebook employees that you're part of a lot of social revolutions, but you need to help join the energy revolution."
A lot of people assume the internet is clean. They think: 'I'm not printing anything, I didn't even have go to the store, I ordered it online and got it delivered to my door'. They don't always realise how much of the internet is powered by dirty energy," said Harrell.
Last year, Facebook announced plans to build two new bespoke data centres, one in Oregon and the other in North Carolina, to cope with ever growing demand as its 500 million users upload photos, post wall messages and build community pages. Facebook is not required by law to disclose its energy use, or its carbon emissions.
Facebook already accounts for 9% of data traffic in the US and a McKinsey report in 2008 estimated that growth in power demand from data centres in the US alone would be equal to 10 new power plants by 2010. Greenpeace says this boom looks set to continue.
"Data centres and telecommunication networks will consume about 1,963bn kilowatts hours of electricity in 2020. That's more than triple their current consumption and more than the current electricity consumption of France, Germany, Canada and Brazil combined."
Facebook's new data centre in Prineville, Oregon, is set to open next month and will require 30-40MW, equivalent to the electricity used by of 30,000-35,000 US homes, according to Greenpeace. Facebook already plans to double its size.
Power to the data centre will be supplied by PacificCorp, which generates 58% of its electricity from coal-fired power stations, mostly in Utah. PacifiCorp was purchased in 2005 in a deal worth $5.1bn, by Berkshire Hathaway which is owned by Warren Buffett – often cited as the world's richest advocate of clean energy.
Facebook says its new data centre will be extremely energy efficient. A spokesperson said: "The Oregon data centre will use an innovative evaporative cooling system … these investments in efficiency design, planning and technology will result in one of, if not the most, energy efficient data centres in the world."
But Harrell said that Facebook had missed an opportunity to follow in the green footsteps of Google and Yahoo. Google has won praise for investing heavily in clean energy and Yahoo also requires utilities to disclose the carbon footprint for supplying a data centre as part of contract negotiations, he said.
"Efficiency in itself is not enough to equal green considering the power that the internet requires. We're not asking Facebook to power their data centres with rainbows and unicorns, but we want them to ask these questions of the utility companies that power data centres," said Harrell.
But Facebook has claimed that sourcing clean energy is not always that straightforward and has even claimed that Greenpeace's record is not so clean, citing a report last year which found the campaign group's data centre using a mix of "dirty energy".