How the Pentagon Secretly Sparked America’s Clean Energy Boom

In the early 2000s, as U.S. troops navigated the harsh landscapes of Iraq and Afghanistan, the price of delivering a gallon of fuel to a forward operating base skyrocketed to more than $400 to $600. 

Supply lines transporting fuel were increasingly targeted, resulting in casualties and operational disruptions. Faced with these pressing tactical and logistical challenges, the Pentagon realized that the nation’s reliance on fossil fuels posed a direct threat to national security.

That realization—and the Department of Defense’s aggressive efforts to address it—quietly kicked off a clean technology revolution that continues today.

According to a new study published in Energy Policy by Nicolas Wittstock, a research fellow at the University of California Institute on Global Conflict and Cooperation, the U.S. government’s most powerful contributions to clean energy innovation didn’t come from climate legislation. 

Instead, they came from internal initiatives led by the DoD and the Department of Energy (DOE), driven by energy security and geopolitical imperatives rather than carbon reduction goals.

A Clean Energy Straggler — with an Innovation Boom

For decades, the U.S. has lagged behind as global peers like the European Union, Japan, and China forged ahead with emissions trading systems, feed-in tariffs, and sweeping green subsidies. It wasn’t until 2022 that the U.S. passed its first significant piece of federal climate legislation — the Inflation Reduction Act.

Surprisingly, during the 2000s, American innovators were at the forefront of developing clean energy technologies, including solar, batteries, and energy efficiency systems, outpacing their global counterparts.

Wittstock’s study sought to explain this paradox.

“Effectively, American clean innovation policy has focused on supporting basic research and R&D instead of directly regulating or encouraging the use of particular technologies by industries or consumers,” Wittstock writes. 

Using a network analysis of over 140,000 patents and more than 1.7 million patent citations from 2000 to 2024, Wittstock found that federal agencies were consistently at the center of U.S. clean tech innovation. 

Of the patents examined in the key clean energy category (CPC Y02), more than 9% were directly funded by federal agencies—a proportion nearly double the federal involvement seen in other technology fields.

The findings were clear: “Federal agencies have been the most important sources of invention within the US clean technology ecosystem since 2000,” Wittstock writes.  “This study complicates the notion of the US as a climate policy laggard and demonstrates how state preferences over technology continue to shape the trajectory of innovation in the American political economy.” 

The DoD’s strategic shift towards clean energy was a pivotal moment

While much of the world’s clean tech R&D is framed around environmental sustainability, the U.S. military’s push into clean energy was born from concerns over the rising cost and logistical risks of fossil fuel dependence.

As the single largest institutional consumer of fossil fuels on the planet, the Department of Defense began sounding the alarm as early as 2001. A Defense Science Board report warned that the military’s sprawling energy demands were creating both budgetary strains and strategic vulnerabilities—especially in conflict zones like Iraq and Afghanistan, where fuel convoys became frequent targets for insurgent attacks.

Moreover, internal fuel pricing didn’t reflect the astronomical costs of transporting fuel to warzones. For instance, while procurement officers might be charged $3 per gallon, delivering that gallon to a combat vehicle could cost $600. The report urged changes to procurement rules and recommended investing in energy efficiency and alternative energy R&D.

As the wars in the Middle East intensified, so did the urgency for efficient energy solutions. By 2010, the Pentagon formally declared energy security a national security priority, with all military branches issuing ambitious plans to reduce dependence on fossil fuels. 

The Army aimed to power all its installations with carbon-pollution-free electricity by 2030 and replace its non-tactical vehicle fleet with electric vehicles by 2035. The Navy set a goal of sourcing half of its energy from alternative fuels by 2020. The Air Force committed to using 50% biofuels in domestic aviation by 2016.

Beyond internal reforms, the DoD also forged formal partnerships with the Department of Energy, turning military bases into testbeds for new technologies and helping to commercialize emerging innovations. “The DoD explicitly declared its intention to speed up innovation and commercialization of new energy and conservation technologies,” the study notes.

From Fracking to Solar: The Federal Footprint

Wittstock’s research shows how the influence of federal agencies—often overlooked in mainstream economic discourse—catalyzed entire industries. For instance, the fracking boom of the 2010s was built on decades of public R&D coordinated by the DOE and its predecessor agencies, which partnered with industry to develop and demonstrate hydraulic fracturing techniques.

Similarly, the launch of the Advanced Research Projects Agency–Energy (ARPA-E) in 2009—modeled after the Pentagon’s famed Defense Advanced Research Projects Agency (DARPA)—channeled billions of dollars into high-risk, high-reward energy R&D projects. Between 2009 and 2023, ARPA-E funded over 1,400 projects with $3.27 billion, attracting more than $11 billion in private follow-on investment.

Patent data backs this up: The Department of Energy and the Department of Defense were the top two sources of patents cited in subsequent clean tech innovations. In network analyses, their patents showed high “hub scores,” meaning other inventors frequently built upon their work. 

Wittstock found that citing a federal agency’s patent made it over 36 times more likely that an organization’s patent would be cited—a marker of influence in the innovation ecosystem.

Creating Markets, Not Just Inventions

These findings complicate the standard narrative of U.S. climate inaction. Even without sweeping laws, the U.S. government acted as a powerful engine of clean energy technology. It wasn’t constrained by political gridlock in Congress because it operated under different mandates: defense readiness, energy resilience, and scientific advancement.

While many state governments also played key roles in incentivizing clean tech through subsidies and standards, this study shows that the federal role — though quieter — was foundational.

Critically, the Pentagon didn’t just invent new technologies—it also shaped markets for them. The DoD’s willingness to act as a first adopter and demonstration partner gave clean technologies a foothold for commercialization. 

Meanwhile, intellectual property reforms like the Bayh–Dole Act ensured that inventions emerging from federally funded research could be licensed to private firms for further development and scaling.

And while the DoD shaped the direction of innovation, it did so largely away from the political spotlight, often under the guise of energy security or military preparedness rather than climate mitigation.

“While the effects of government action in this domain can be considerable, it is a relatively low-visibility form of state capacity,” Wittstock notes. “Most federal R&D initiatives are related to national security efforts and have generally enjoyed support from a bipartisan consensus on the importance of federal science and technology investments.”

What Comes Next?

The federal clean energy engine revved up in the early 2000s continued churning through Republican and Democratic administrations alike. 

Despite hostility toward climate policy, even the first Trump administration did little to dismantle ARPA-E or DOE research efforts. The Biden administration ramped up support through the 2022 Inflation Reduction Act, offering historic subsidies for clean energy manufacturing and adoption.

However, Wittstock warns that the current political environment may threaten these gains. Some signals from the current administration suggest a retreat from clean tech investments at the federal level, including potential cuts to ARPA-E and a shift in the DoD’s focus from mitigation to adaptation.

“The Department of Defense does not do climate change crap,” Secretary of Defense Pete Hegseth said in a March post on X. “We do training and warfighting.” 

“It is currently unclear what these developments will mean for the future urgency with which DoD and DOE will pursue clean technology,” Wittstock concludes. “What is clear, however, is that since the early 2000s until the time of writing, clean technology R&D efforts pursued by federal agencies have made impressive strides in spurring technological innovation.” 

In other words, America’s clean tech revolution in the 2000s wasn’t sparked by partisanship or pressure from environmental groups. It began with warfighters in the Pentagon, driven by military strategy and national defense priorities.