America's Department of Defense has set a bold goal to generate a quarter of its power from renewable energy sources by 2025. That bold goal has the military targeting the installation of solar panels from the likes of SolarCity (NASDAQ:SCTY) and SunPower (NASDAQ:SPWR) on military bases across the country. However, solar is just one of the renewable technologies the military is investing in as it's also pursuing wind, geothermal and biomass technologies.

While most of these technologies are still emerging energy platforms, each is starting to become rather mainstream. That can't be said for some of the other innovative ideas the military is pursuing as it invests to become a lean, mean and green fighting force.

The following slideshow details some of the innovative energy projects that the military is investing in these days. It walks through some of the projects that Solar City and SunPower are working on for the military as well as some of the more unique ideas the military is pursing and why it matters.