The Defense Department uses more than four times as much energy as the other government agencies combined, and accounts for almost all the government's petroleum consumption, according to the Department of Energy.
Security and environmental concerns associated with fossil fuels are part of the reason the Pentagon is pushing energy efficiency and renewable energy, said Dennis McGinn, a retired vice admiral for the Navy and a senior fellow at Rocky Mountain Institute in Snowmass, Colo.
But the price of oil, hovering above $60 a barrel, has increased the pressure to cut energy costs.
"That's a game-changer," McGinn said of high oil prices. Renewable energies that used to be more expensive than fossil fuels are becoming increasingly attractive.
"Because the DOD is such a large consumer of energy ... it creates a demand on the market" and encourages companies to invest in renewable energy research, McGinn said.
As the DOD becomes more energy efficient, renewable sources can better meet the military's demand. And less demand means smaller environmental footprints left by alternative sources such as solar and wind farms, he said.
Movements in the military to use green energy in buildings began more than 10 years ago as an investment, but there is a growing awareness that moving to green or alternative energy makes sense economically and environmentally, McGinn said.
For example, alternative energies such as wind farms and fuel cells cut the costs of transporting large amounts of fuel to remote locations and areas of conflict, he said.
The Navy has a goal of dedicating up to $170 million per year to energy efficiency projects, according to Navy spokesman Lt. William Marks.
One way the Navy tries to increase the fuel efficiency of its ships is using copper-containing coatings on hulls to decrease film buildup and drag in the water. Other efforts to decrease consumption range from designing more efficient ships and engines to automatic lights that turn on when people enter a room, Marks said.
The Navy has also developed an incentives program for ship fuel efficiency. Ships that save oil by burning less fuel can keep up to 40 percent of money saved for the vessel's needs, he said.
A Defense Department memo from November 2005 outlined energy management goals for the military, which included reducing energy consumption in facilities by 2 percent per year, and reducing greenhouse gas emissions from facilities 30 percent by 2010.
The memo also called for producing or buying renewable energy "to help alleviate the Department's reliance on fossil fuels." It set a goal of using renewable energy for 25 percent of its electricity demand by 2025, provided doing so would be cost effective in the long term.
The Air Force has already gone beyond a 2013 target, using renewable sources for 11 percent of its electricity, according to Air Force spokeswoman Nicole VanNatter. The Air Force leads the nation in purchasing renewable energy, she wrote in an e-mail.
The Air Force plans to increase use of E85 -- a motor fuel of 85 percent ethanol and 15 percent gasoline -- by expanding service stations and pumps that support alternative fuel vehicles, VanNatter said.
About 80 percent of the Air Force's energy budget in 2005 went toward the more than 2.1 billion gallons of aviation fuel used for aviation operations. Because of this, the Air Force created a working group to evaluate how aviation operations can be more energy efficient, she said.
A December report on the Defense Department's energy management for fiscal year 2005 put oil consumption by the department's facilities at more than 169.7 million gallons per year, costing more than $207.79 million per year. The report expected a decrease in oil consumption for fiscal years 2006 and 2007, but an increase in cost to more than $287 million in 2007.
A Defense Department renewable-energy report to Congress in March 2005 said: "The renewable energy industry continues to grow in capacity and is steadily improving technologies to enhance performance, rendering it increasingly cost-competitive. DOD can become the early market of choice, benefiting from these trends."
The report evaluated the effectiveness of different sources of renewable energy, and gave a timetable for expected payback benefits. Geothermal power plants cost more than diesel generators, but are a reliable power source that could give back five times the investment costs over 20 years. Wind power plants would give back 1.5 times the cost; a hybrid wind-solar plant would cover costs; and a solar plant would not pay back within 20 years without government incentives, according to the report.
Biomass could be a good resource in Southeast states because animal waste is plentiful, according to the report.
Solar photovoltaic power is expensive, but could be cost effective in states with incentives or mandates. The report said most locations could implement daylighting, a way to save electricity by using windows and skylights rather than electric lights in buildings during the day.
"The goal is to purchase renewable energy at or near the price of conventional energy," the report said. "The primary focus is on using DOD's purchasing power to encourage development of renewable resources."
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