Level 3, a US-based provider of communications and data center services, said three of its data centers in Europe were powered completely by renewable energy sources.

Utilities serving power to one Level 3 colocation facility in Amsterdam and two of its colocation facilities in London have issued the company with documentation certifying that the facilities are powered solely by renewable sources, including wind, hydro and solar.

This is a rare move for a company that wants to decrease its carbon footprint. More commonly, companies pay the premium for renewable energy to a utility, which then serves them energy through a shared grid. Electrical grids usually get energy from a mix of sources, including fossil-fuel plants and renewable-energy sources.

Commenting on the announcement, James Heard, president of European markets at Level 3, said: "With three data centers 100% reliant on renewable energy for commercial power, Level 3 ... demonstrates our commitment to achieving excellence in its protection of the environment and sustainability."

In addition to buying renewable energy from utilities, companies that want to offset their carbon emissions also buy carbon credits. Others, such as Google, invested in development of renewable-energy sources or contracted directly for energy renewable-energy producers generate. In such cases, the customers still get their energy from a common grid, with a mix of sources.