The Army has placed an increased emphasis on the importance of sustainability over the last several years, and California's Fort Hunter Liggett stands as a testament to that. The base is one of several throughout the United States working toward becoming net zero energy and net zero waste by 2020 and it recently took significant steps toward that end, according to the Army's official website. 

One of the biggest construction projects on the base – four solar microgrids – is being led by the Army Corps of Engineers. The hope is that the project will be able to create enough energy to supply power to at least 300 homes by the end of May. Eventually, base officials hope to be entirely energy independent. Not only will it save the military money, but it could also improve training and readiness.

"Prior to the installation of these solar projects, we were susceptible to power outages quite frequently," Bob Roy, project engineer with the Corps' Sacramento District, told the website. "That interrupts the ability to train the troops indoors and outdoors."

Fuel efficiency can save the military a significant amount of money. According to CNN, in 2008 the Department of Defense spent $17.9 billion on energy costs.