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America's 'greenest' big companies and institutions

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Whether it's carbon neutral office blocks, automated lighting systems or a commitment to plant thousands of trees, governments and businesses all over the world are always keen to trumpet their green credentials.

In 2001, the United States Environmental Protection Agency (EPA) established the Green Power Partnership as "a voluntary program that encourages organizations to use green power as a way to reduce the environmental impacts associated with conventional electricity use."

Here, takes a look at the Green Power Partnership's National Top Partner Rankings, which detail and rank the green energy use of the scheme's partners.

By Anmar Frangoul, special to, on Wednesday March 4, 2015.

Isaac Brekken | For The Washington Post | Getty Images