By Rebecca "Becky" Halstead, Brigadier General (retired)

The U.S. Department of Defense (DoD) has a long-standing tradition of accelerating technological innovation, serving as early adopters and impacting the broader commercial market in such areas as aviation, computing and global positioning systems (GPS).

For the past several years, the DoD has been playing this same role in the renewable energy space. In fact, the Pew Charitable Trusts reports that DoD clean energy investments increased 300% between 2006 and 2009, from $400 million to $1.2 billion.