Military bases are huge. And they have lots of open space. So much open space, in fact, that bases in Southern California could become solar power generators - contributing up to $100 million per year in revenue to the federal government, according to a new study commissioned at the request of Congress.

The Department of Defense has a huge power bill, some $4 billion per year, according to this story in CleanTechnica that sums up the findings of a year-long study for the military by Virginia-based analytical firm ICF International. Even though 96% of the open space would be considered off limits, the remaining 4 percent is enough to generate 7,000 megawatts, which, CleanTechnica states, is 30 times more power than the bases consume.

The government could receive $100 million in rent payments, reduced cost power, in-kind contributions or some combination thereof, the study states. The military solar could generate enough power to supply 1.75 million homes, according to industry estimates.

However, it's unlikely that all of that 4 percent would be claimed. Much of the land is remote and access to the transmission grid poses significant challenges. That said, about 25,000 acres at military bases in Southern California are "suitable" for development, and about 100,000 acres are "likely" or "questionably" suited for solar development. The researchers assumed 100 percent of the 25,000 "suitable" acres and 25 percent of the "likely" and "questionable" land could be turned over to private solar developers.

Most of the installations already contain one to two megawatts of solar power - and large chunks of property that can't be used for solar. Modern weapons systems and other issues - flash flood hazards, steep slopes and conflicts with native habitat - prevent development of the overwhelming majority of the land.

But covering just 6 percent of the potentially available land would generate enough power to meet the military's 2005 renewable-energy goals, the report states.

Five types of solar projects were considered: rooftops, shaded parking lots; shading structures over unpaved parking lots; and ground arrays.

As CleanTechnica notes, "military bases occupy more than 30 million acres of land, much of it in areas with lots of sun, and they need a secure supply of electricity as a matter of security..."

So, why not use solar? The clean energy would help California reach or exceed its ambitious 33 percent renewables mandate and, when combined with other innovative programs (such as using rights-of way under transmission lines; More on that here,), would put otherwise waste land to productive use.

To unlock that potential, the authors put forth the following recommendations for the Department of Defense:

Work with stakeholders to accelerate construction of transmission lines; develop microgrid technology on the military bases (like this project) and further refine its energy-security goals; provide incentives for military installations that invest in energy technology; and work with the federal Bureau of Land Management (which also leases land to solar companies) to ensure the government is getting fair rents.

Here is a New York Times story on the report.

Photo: Solar array at Fort Hunter by http://www.army.mil/