Department of Defense Completes Renewable Energy Assessment

March 7, 2007

The Department of Defense (DOD) has a long history of pursuing renewable energy, and currently has a diverse energy portfolio that includes several non-fossil sources including wind, solar, geothermal, hydrogen, and biomass generated power. In 2002 and 2004, Congress appropriated funds for DOD to assess wind, solar, and geothermal energy resources at domestic military installations and to identify opportunities to increase the use of power from renewable sources. Completed in 2005 this assessment provides the first truly comprehensive evaluation of renewable energy use by installations, and considers resource availability, electricity purchasing, mission compatibility, energy security, and short- and long-term perspectives. It also provides a technical and economic foundation for DOD to pursue onsite electricity generation from renewable energy to reduce market and infrastructure vulnerabilities. The information produced through the assessment provides the foundation for a new, aggressive renewable energy strategy, and has spurred the development of many projects.

DOD's renewable energy strategy is two-fold. First, based on the results of the study, DOD is increasing generation capability over the next several years on its military installations. For example, the Navy recently completed a 20-kilowatt photovoltaic system at Naval Air Facility El Centro, California; the Air Force recently completed a 1.5 megawatt biomass gas plant at Hill Air Force Base, Utah; the Army is installing a 35 kilowatt photoelectric renewable power system at Kwajalein Atoll; and the Marine Corps recently finished the construction of an on-installation bike path illuminated with solar energy at Marine Corps Air Station Yuma, Arizona. Second, DOD is working with industry and commercial sector partners to pursue several large promising renewable energy opportunities, including the purchase of renewable power and the development of new geothermal and ocean thermal energy conversion projects. The combination of these two approaches will enhance energy flexibility as well as help decrease reliance on fossil fuel energy.

Wind Energy

The assessment concluded that more than 200 sites have some on-site wind development potential. The economics of wind power generation has led to the conclusion that while several small turbine projects should be pursued on a case by case basis, the most advantageous approach is to pursue large purchases through commercial development. Depending on market prices for power, only a few sites are suitable for utility-scale development by private partners. The remaining sites may only be economical to develop if long-term power prices continue to escalate. The assessment also identified a number of barriers to development of viable projects, such as mission conflicts, environmental and flight path restrictions, and radar interference. Understanding and contending with these identified barriers is imperative to successful development.

Solar Energy

The solar assessment identified several specific solar technologies expected to be widely applicable to the energy uses and building types on military installations. Each technology was evaluated against utility costs using available solar information and representative technology performance and cost data. Some solar projects are potentially cost-effective at almost all DOD sites, assuming utility rates remain high and appropriate buildings and energy uses exist for specific solar technologies (i.e., swimming pools heated with solar pool heaters). Solar thermal technologies fared best in the assessment, especially daylighting and transpired solar collectors to pre-heat inlet air in hangers with forced air heating. Solar photovoltaics are only economic in areas with high electricity prices and high state and utility incentives for solar power. The results of this assessment are currently being used in a joint effort with the Department of Energy's Federal Energy Management Program (FEMP) to pilot a new acquisition approach through energy savings performance contracts (ESPC) that will attempt to mass replicate a selected few of these economically viable solar applications at military installations throughout an entire geographical region.

Geothermal Energy

Two types of geothermal evaluations were conducted: 1) the potential for utility-scale electric power production and 2) direct use of geothermal resources for building heating and cooling systems. The greatest potential for geothermal development is in sparsely populated areas of the western United States. Most military facilities in these areas are used for training exercises that require lots of land, but have little demand for electricity and heating. These facilities are typically far from the utility grid and, as a result, geothermal resources on military lands are generally less attractive for private development.

Biomass Energy

While not specifically studied in the renewable energy assessment, DOD is extremely interested in pursuing renewable energy from biomass sources. The most economic opportunities appear to be viable through ESPCs for on-site development and long-term commodity purchases for off-site commercial development. Of interest is that many installations possess, or are located close to, many ideal sources of biomass energy including landfills, anaerobic digesters, and agricultural waste.

Purchasing Strategy

In most cases, renewable resources developed near but not on military lands are more economical than on-site projects. Use of long term commitments for commodity purchases is viewed as the key to encouraging commercial development of renewable energy resources near DOD installations. Additionally, DOD routinely requests price quotes for renewable energy when it solicits power supplies in competitive markets.


The Department of Defense is firmly committed to supporting the President's agenda on renewable energy and his stated objective of reducing our nation's reliance on fossil fuels. Since the Department accounts for about 78 percent of the federal government's energy consumption, DOD's intent is to lead by example in the areas of renewable energy, energy efficiency, and energy conservation. DOD has an aggressive program with many initiatives already underway that incorporate several different approaches including third party financing, on-site construction, and energy commodity purchases. DOD's renewable energy portfolio will continue to increase as the performance of new technologies improves and costs are reduced. As a result of the renewable energy assessment, DOD has programmed over $18 million worth of new renewable energy projects in the FY 2006 President's Budget, which is a significant increase in investment over prior years.

For more information, please contact Jim Snook of the Air Force Civil Engineer Support Agency at or 850-283-6295.