Officials broke ground late last month at the Army installation 75 miles north of Austin on a massive solar farm -- 63,000 panels covering 132 acres, or roughly the size of 100 football fields.
The solar project, which is being paired with an investment in a Panhandle wind farm, is the Army's bid at seeing whether it can take long-term measures to shave its $1.3 billion annual energy bill.
Fort Hood's solar and wind project, the largest undertaken by the Army, will cost roughly $100 million -- but officials say it will save $168 million over the next three decades and account for nearly half the power used on the post, or the equivalent of the power consumed by about 10,000 households over a year.
Renewable energy produced on Army installations increases energy security and mitigates rising energy costs, officials say.
Overall, the military, the single largest consumer of energy in the U.S., is dedicating at least $7 billion to renewable energy projects -- part of the Obama administration's efforts to emphasize cleaner, alternative sources of energy.
The deal has been embraced by officials at Fort Hood, home to roughly 40,000 soldiers.
Meeting Pentagon orders for more energy-efficient installations, the post had successfully cut its energy consumption by about 30 percent over the past 10 years by using energy-efficient technology and changing soldiers' behavior, said Brian Dosa, the installation's public works director.
And in 2012, the post activated a solar field of nearly 3,000 photovoltaic panels, generating enough power annually for 300 homes.
But with only a small staff and light resources, Dosa said he had been struggling to take the next step in greening the installation's energy mix.
So when Army officials called to ask whether Fort Hood would be interested in participating in this massive project, Dosa said, "I nearly fell out of my chair."
With its far-flung installations, sometimes in hostile terrain far from power plants or electricity infrastructure, the Army has been exploring ways to speed the development of distributed energy -- newfangled ways to generate electricity such as mini-solar panels.
The renewable energy project is part of an effort to "increase resiliency of the Army installation, by generating electricity on post and not being totally dependent on drawing energy from the grid," Dosa said. "This is a giant step toward energy security at Fort Hood."
Apart from the electricity needed for helicopter simulators, Fort Hood's energy needs mirror those of any small city: Lighting, air conditioning and infrastructure are among the chief demands. Overall, the base consumes about 250 gigawatt-hours of power annually, or roughly the amount used by 22,500 households.
Under the terms of the renewable energy deal, Apex Clean Energy Holdings, a Virginia-based company, will install about two dozen wind turbines in Floyd County, in addition to the solar panels at Fort Hood, for a total of 65 megawatts of capacity.
Apex Clean Energy will develop, finance, design, install, own, operate and maintain the project; the Army will buy electricity generated at the two sites at a locked-in overall rate of a little over 5 cents per kilowatt-hour. That rate is cheaper than the military currently pays for electricity at Fort Hood, Dosa said.
The solar panels and wind turbines could be operational by the end of the year, Dosa said.
"The Army is committed to partnering with industry to implement large-scale renewable energy projects that will strengthen the resiliency of our installations through increased energy security and sustainability," said Katherine Hammack, assistant secretary of the Army overseeing installations, energy and environment.
At the ceremonial groundbreaking in late January, U.S. Rep. John Carter, R-Round Rock, touted the project's benefits.
"Using renewables makes sense on ... military posts throughout the country," Carter said, according to a news release from Fort Hood. "More importantly, and what we're all about here at Fort Hood, it frees up money to be able to make better soldiers here on Fort Hood. So, if it's cheaper energy, it gives us more money in our pockets to spend on training up the best warriors in world."