U.S. defense contractor Lockheed Martin said it signed a deal to buy enough solar-generated energy to power its entire domestic business segment.

Lockheed signed a 17-year purchase agreement to get solar-generated electricity from Duke Energy Renewables. The company has a new solar facility in North Carolina that, as the largest plant of its kind east of the Mississippi River, is producing 80 megawatts of total energy. Lockheed secures about 40 percent of the total output.

"Signing this agreement for the acquisition of large-scale renewable power is a significant milestone towards our commitment to environmental stewardship" Carol Cala, a Lockheed vice president in charge of energy development, said in a statement.

The Department of Defense has called for the addition of 3 gigawatts worth of renewable energy to help meet the electricity demands of military facilities by 2015. The mandate is part of a broader departmental directive to use renewable energy resources for at least 25 percent of its energy consumption.

For Lockheed, the company has an internal mandate to cut greenhouse gas emissions by 35 percent of its 2010 baseline emissions by the end of the decade. According to information outlined by the company, the U.S. Environmental Protection Agency ranks Lockheed near the top in terms of U.S. corporate users of renewable energy.

Before the agreement with Duke was signed, the company said it was relying on low-carbon sources to meet 16 percent of its electricity demands.

A report Tuesday from the federal government finds the electricity generated from low-carbon resources is expected to increase by 9 percent this year. Onshore wind facilities will account for the bulk of increases, with smaller contributions from new hydroelectric power.