The Army is installing a 4-megawatt solar field on a 42-acre tract at its White Sands Missile Complex in central New Mexico as part of its efforts to generate more renewable energy.
The $16.8 million project to be completed in December will generate about 10 percent of the installation’s power and will cost the Army the same amount it currently pays for its electricity, according to the service.
The project is being funded through an energy savings performance contract (ESPC) - in which the vendor pays the upfront costs of facility renovations and retrofits in exchange for payments from the Army’s energy savings over time. The contractor guarantees the energy savings for the life of the contract or it has to pay the balance.
The Army will also purchase energy from contractor Siemens Government Technologies Inc., which will maintain the equipment for 25 years.
Agencies across the government racing to meet federal renewable energy mandates have to decide what type of energy to pursue — solar or wind.
Jeff White, vice president of Army programs at Siemens Government Technologies, said solar projects can be almost any size and allow agencies to meet energy goals by building small projects.
Solar is ideal for military installations because panels can be fitted into “buffer zones” near testing or training areas, he said.
Wind turbines are more challenging because they take up more space, and that can interfere with lines of sight for incoming aircraft, he said.
“You’re talking about a 300-foot-high obstacle with turning blades near an airfield,” White said. “Solar installations eliminate all that.”
The biggest limitation for solar is that there has to be lots of sunlight, he said, but both wind and solar power allow agencies to operate remote installations in areas where there is no power infrastructure.
A January Defense Department report said the department could generate up to 7 gigawatts of solar power at just 10 Air Force and Army installations in the Mojave and Colorado deserts in the American southwest — but there was less potential for solar development in the northern and eastern parts of the country.
One megawatt is enough to power 300 homes, according to the Energy Department.
The Massachusetts Military Reservation in Cape Cod, Mass., is operating two wind turbines capable of generating 1.5 megawatts of renewable energy.
The turbines — which will save the installation $1.5 million a year — were built to offset electrical costs for powering numerous groundwater cleanup systems at the reservation.
The 400-foot-tall turbines were placed in an area of the 22,000-acre installation where they will not affect any aircraft, according to the service.
The Navy installed three 225-kilowatt wind turbines on San Clemente Island off the coast of southern California in 1998 to help power its 57-square-mile testing range.
While the total cost was about $2.2 million, the reduced fuel transportation costs saved the service $160,000 annually.
Jeff Sherman, federal energy director at contractor Schneider Electric, said solar and wind are at different points in their development. The solar industry has developed numerous ways agencies can use solar energy, including mounting panels on roofs or on small patches of land, while wind energy still mainly comes from large turbines.
“Big wholesale wind turbines don’t always fit on small pieces of property,” Sherman said.
He added that agencies that construct wind turbines typically are working with a larger amount of land.
Solar power has the advantage of being able to provide power at specific locations without having to be connected to a larger grid, according to the Energy Department. That makes it ideally suited for remote locations or outdoor lights.
But wind energy can be cheaper than the cost of conventional electricity in areas with high wind, according to the agency.
Some agencies are trying to do both: The Energy Department’s Argonne National Laboratory in Argonne, Ill., launched a sustainability program in 2009 and saved $500,000 in energy costs over the last two years, in part by installing solar panels and miniature wind turbines to power its outdoor lights.
The Agriculture Department has also installed more than 500 solar systems and wind turbines since 1990, primarily to power remote stations and water wells, according to the agency.