Obama picks green advocate as Navy energy chief

The Navy plans to get half its energy from nontraditional sources by 2020. The White House has promoted the Navy's transition to biofuels to power its fleet, and the Navy is also working toward getting 1 gigawatt of power from renewable sources, among other goals.

Some of those goals, however, have triggered GOP criticism. They say renewable energy programs are too expensive in an age of budget sequestration that threatens to chop $500 billion from the Pentagon in the next decade.

The Navy and Defense Department have said transitioning to renewable energy enhances security, keeps spending disassociated from volatile oil prices and reduces the effects of climate change, which the Pentagon has called a national security issue.