Defense

How US military bases became proving grounds for clean energy technology

Correction: This article has been updated to reflect that the Costs of War Project is based at Brown University, and military aircraft in general — cargo included — are responsible for the biggest block of military emissions.

The cost and security advantages of renewable energy are driving their adoption on U.S military bases — a development with significant long-term implications for the civilian market.

The military’s demand for inexpensive, hard-to-disable power for its constellation of bases has driven it to collaborate with civilian contractors in exploring a new generation of “off the shelf” clean tech.

Military bases have played a similar role since the Obama era in helping to “de-risk” other frontier technologies that are now a growing bulwark of the power system — like the once-exotic pairing of solar and wind power with large-scale batteries.

Now, military labs and bases stand out as proving grounds and early adopters of many forms of renewable energy that are promising but still prohibitively costly.


These include geothermal powersmall modular nuclear reactors, long-term energy storage and electric vehicle (EV) fleets that double as roving, grid-buttressing batteries.

Experts told The Hill that Defense Department sponsorship of renewable energy pilot projects across the U.S. military base system was a major force pushing toward the evolution of “standard-issue” clean tech solutions — lowering costs and facilitating future adoption by cash-strapped municipalities.

Military bases serve as good sites for adoption of these developing technologies in part because they resemble small towns, but lack some of the hurdles that can slow down decisionmaking in town governments. If a base commander is on board with a pilot project, it can be implemented without first being debated by a city council.

One major reason the military is adopting such projects is because it sees climate change as contributing to a significantly more dangerous world. Another: Its commander in chief told it to.

In December 2021, President Biden signed Executive Order (EO) 14057, which directed the federal government to use “its scale and procurement power” to convert to a balance of 100 percent carbon-free electricity — with at least 50 percent of its electricity coming from clean sources at any given time.

The measures the military is taking to shift to such energy sources are controversial to the GOP — at least, as long as they’re tagged as being about the climate.

The draft version of the mammoth annual defense policy bill released last week by the GOP-controlled House Appropriations Committee would ban the agency from using any of its funds to implement any Biden-authored “climate change initiatives,” including EO 14057 — thereby saving $661 million, or 0.07 percent of the defense budget.

Lawmakers’ position on the efforts is more bipartisan, however, when the climate change language is taken out and the focus is put on cost or reliability. The House Appropriations Committee quietly dropped an attempt by Rep. Marjorie Taylor Greene (R-Ga.) to ban agency funds for being used to purchase EVs or charging stations, for instance. 

The Defense Department has found that the electric vehicles produce less on-base pollution and have a lifetime cost significantly “lower than comparable” gas-burning cars — which is a primary reason why the agency is trying to electrify its base fleets. 

A number of nonclimate benefits make EVs close to ideal for the commuter fleet on a military base, Michael Wu, co-founder of consultancy Converge Strategies, told The Hill. 

Base vehicles — whether sedans used for commutes, vans used for deliveries or Defense Department Education Activity school buses — tend to drive short, predictable distances each day, before returning to a set location.

That means they don’t run into the issues with range or speed that have hampered military attempts to roll out electric tactical vehicles. 

It also means that they can be used to bolster the base grid itself. The way base vehicles are used makes them “a really good test case” for vehicle-to-grid technologies, in which EV electric batteries can return power to the grid during a disruption, said Wu, who served as adviser to the assistant secretary of the Air Force on distributed energy and energy resilience issues.

Right now, he said, “we have a totally one-way system, both for transportation and for electricity. You generate electricity at a power plant — it goes out everywhere to end-consumers in the same way that our transportation system sends out oil that goes out and it gets distributed to gas stations.”

A future base grid, by contrast, is more likely to be two-way — a complex flow of power in and out of batteries, some of which may occasionally be driving. The Defense Innovation Unit is currently working with seven vendors in a pilot attempt to roll out chargers across its bases. 

Last fall, Northern Virginia contractor Leidos won a deal to provide charging infrastructure to 49,000 EVs — and associated energy storage — at Air Force bases around the country. 

Products like that help the military break its reliance on the current workhorse of its backup power system: the polluting, often-unreliable diesel generator, Wu added.

EVs reflect two of the main reasons renewables are appealing to the Defense Department. First, they are comparatively cheap, so their adoption frees up money for fighting wars in a world where the warming climate functions as a “threat multiplier.” They also help free the agency from dependence on fossil fuels, with their geopolitical choke points and fluctuating prices.

But perhaps even more important is the security renewables could offer: the assurance that a base besieged by a foreign adversary or cut off by natural disaster or cyberattack could manufacture its own power.

The fear of such disconnection — combined with growing wariness about Chinese dominance of solar panel and battery supply chains — is driving Defense Department interest in other solutions, like nuclear power and geothermal energy, said John Conger of the Center for Climate and Security, who oversaw military bases, energy and the environment at the agency throughout the Obama administration.

Biden officials often put their clean energy aspirations in the context of a new Cold War, even when discussing domestic energy. While America’s foreign and domestic bases used to be thought of as safe from attack, a heightened strategic competition with China means that military “installations are no longer a sanctuary,” Ravi Chaudhary, assistant secretary of the Air Force for energy, installations and environment, said last year.

Chaudhary was introducing a half-dozen new Defense Department geothermal energy proposals that seek to tap the heat of the earth for clean, on-demand energy. 

Geothermal energy is a particularly promising solution for the military — virtually every base in the country is on top of subterranean resources they could use for heating and cooling, and many could use it for power.

But it’s only one of several types of clean energy the Defense Department is exploring or building out. 

The agency is in contract disputes over a proposal to put a nuclear “microreactor” at Eielson Air Force Base in Alaska. It’s funded development of technologies to tap the power of waves at the Navy’s Wave Energy Test Site in Oahu, Hawaii. 

And in California, Marine Corps Air Station Miramar runs a base-scale microgrid off a combination of solar power and — as a backup — methane gas that would otherwise be emitted from a local landfill. During rolling blackouts amid a stifling heat wave in August 2020, some San Diego neighborhoods drew power from the station.

These projects are all largely speculative, and they suffer from being bespoke — built to order, and therefore expensive. 

Solar power was in a similar stage in 2009, when the Obama administration announced something that had never been tried before: a new 14-megawatt solar project at Nellis Air Force Base in Nevada.

When it was inaugurated, then-President Obama promised the base would stand as “a shining example of what’s possible when we harness the power of clean, renewable energy to build a new, firmer foundation for economic growth.”

At the time, this seemed like a lofty idea. In modern terms, the solar installation was small. It was also primitive: Without battery backup, heavy cloud cover could throw the base back into reliance on diesel generators.

But it helped lay both the technological and financial foundation for what came later. The deal for the $100 million facility rested on a trade: The Air Force didn’t have to pay any upfront money for the solar plant, and the solar developer, SunPower Corp, didn’t pay anything to lease the land.

Instead, the financial foundation of the project rested on a “power purchase agreement” — a contract under which the Air Force base committed to buy a predetermined amount of electricity from the local utility, the Nevada Power Company, which drew additional electricity from the new solar project. This agreement, in turn, helped SunPower Corp get the loans necessary to build the project and supply Nevada Power — putting more renewable energy on the grid.

This power purchase model is now standard for the wind and solar industry — and it provides a financial template for startup industries like geothermal. And in the past 15 years, solar has gone from exotic to essential — both for the grid as a whole and for the military.

In January, California’s Edwards Air Force Base became home to the biggest solar farm in the U.S. — which was bolstered by the biggest battery plant in the world. At 1.6 gigawatts, it is more than 100 times larger than the 2009-era Nevins project, and represents the biggest public-private partnership in Defense Department history, according to the agency.

It’s also a significant source of revenue for the department. The project, built in conjunction with renewables developer Terra-Gen, is enormous: 1.3 gigawatts, enough to power nearly a quarter million homes — 25 times the base population — which means the excess will be sold in the rest of energy-hungry California. Under the terms of the lease, the Defense Department could receive as much as $75 million for the power produced on base.

This model — identifying a need and putting out a request for bids to the civilian market — is the key strategy followed by the Defense Department as it helps develop various forms of technology. 

The practice dovetails with a broader philosophy surrounding military contracting: the principle that wherever possible, military gear should have civilian applications — or simply be repurposed civilian technology. 

Long gone are the days when the Defense Department was a major spender on American research and development — and for all its considerable size, the agency isn’t big enough to justify entire supply chains.

Therefore, “almost everything we do has a dual-use component,” Casey Perley, executive director of the Army Applications Lab, told The Hill. 

Whether it’s a solar plant, a geothermal borehole or a small modular reactor, the Defense Department gets new resources by committing to buying power for an extended period of time, “which allows the contractor to borrow money to do that,” Conger said.

That also makes the military an important source of early defense-contract funding for renewable technologies — or companies — getting off the ground.

In the case of the proposed small modular reactor at Eielson Air Force Base, Conger added, the Defense Department “is not buying the reactor, they’re buying the power, and that is enough of an anchor that they can put out bids.”

There is a lot of inefficiency baked in to this approach, argued Neta Crawford, a professor of international relations at Oxford University and co-founder of the Costs of War Project at Brown University. While military bases are analogous to civilian small towns — albeit run under a command-and-control system — much of the military tech suite is poorly designed for civilian use.

Crawford sees the agency’s funding of clean technology as essentially parasitic to the broader climate fight. “We have every technology we need to make a rapid transition,” she told The Hill. 

The Defense Department, Crawford said, “is siphoning resources for their favorite tech,” when direct spending from the Energy Department would be more useful for civilian needs. She argued that the same holds true for universities and the private sector: Costs of War found that between 2021 and 2023, venture capital poured $100 billion into military tech startups — money that would be more effective at speeding the energy transition if spent on non-military projects.

In terms of the military’s carbon footprint, there’s a powerful argument that the best thing the Defense Department could do for the climate is stand down, said Crawford.

The biggest contributor to military emissions is military aircraft, a large component of which is the jet fuel burned in the cargo fleet that keeps the dispersed empire of American military bases supplied, she argued.

“We have over 700 bases,” she said. By contrast, “China, which is supposed to be our primary enemy, has one overseas base. Which is in Djibouti — where we also have a base,” she added. 

“We have tens of thousands of people still based in the Persian Gulf to protect for the most part oil that we shouldn’t be burning.”

For all its spending on clean energy, and its particular progress around small-scale grids, Crawford argued, the U.S. needs to have a serious conversation about “right-sizing” its military.

Even on its own terms, the process by which the military helps develop technology on bids from civilian markets has its own hiccups. Last fall, the Air Force accepted a bid from Oklo, a nuclear power startup chaired by Sam Altman of OpenAI, the tech company that built chatbot ChatGPT.

But the Eielson project — which seeks to replace the base’s coal plant with a 20 MW nuclear plant, or one of just slightly higher capacity than the 2009-era Nevins solar plant — is currently stalled, as a competing bidder challenges the project in court.

These growing pains, Wu said, are part of the process that new technologies need to follow. For small nuclear reactors in particular, “once you get the first one done, the next 10 will come relatively quickly. But the first one or two are gonna be very, very difficult.”

For nuclear in particular, he argued, the business problem is compounded by the problem of getting the public comfortable “with those things in their, you know, closer to their backyard, and not in the middle of the Pacific Ocean,” powering an aircraft carrier or submarine. 

But he added that the argument for nuclear power gets easier to make with every additional reactor that gets built — and the military’s mandate for reliable, always-on and uninterruptible power helps get prototype projects funded that would otherwise be too expensive for civilian markets.

That, in turn, helps push the price down for the next generation of projects, pushing the industry toward the military’s ultimate goal of off-the-shelf, standardized solutions. 

“There are more than 500 [Defense Department] installations worldwide,” Wu said. “A lot of these technologies cannot be as bespoke as they are today.”

Updated June 21 at 10:44 a.m.