This nuclear waste site could soon host a massive solar installation

The U.S. Department of Energy announced plans last week to transform a contaminated former nuclear weapons production site into what could be the largest solar project in the country. The installation would stretch across up to 8,000 acres in south-central Washington state and boast up to 1 gigawatt of energy capacity — enough to power 750,000 homes.

One of the core challenges of building large solar installations is deciding where to put them. Local residents and farmers sometimes protest the use of agricultural land, while environmentalists urge caution in disturbing ecosystems. But this project location, known as the Hanford Site, is heavily contaminated from decades of atomic weapons production — first as part of the Manhattan Project and later during the Cold War.

Weapons production at Hanford created around 56 million gallons of radioactive and chemical waste, plus millions of cubic feet of solid waste and billions of gallons of less contaminated liquids. During production and upon Hanford’s decommissioning in the early 1990s, much of this waste was disposed of in concrete-lined pits, trenches, and ponds, and has since leached into the Columbia River basin, contaminating groundwater and causing health issues for locals.

Building solar at this location is ​“a great way to reuse land that has limited potential for other uses,” said Nels Johnson, senior advisor for renewable energy at The Nature Conservancy, who notes that ​“it means we’re not converting” prime farmland.

The project is part of the DOE’s new program Cleanup to Clean Energy, launched last year to help attain the climate goals in President Joe Biden’s 2021 executive order directing federal agencies to develop clean energy generation on their properties, with the goal of those agencies achieving 100 percent clean electricity by 2030.

The department announced the program’s first two projects — also solar installations — in June and July. One project will be located on 890 square miles of Idaho National Laboratory land and will feature 400 megawatts of solar capacity. The other will take up 2,400 acres of the Nevada National Security Site and has a capacity of 200 megawatts.

The Hanford project aims to generate the most energy by far — and, in addition to potentially becoming the largest solar project in the country, Johnson said that it would certainly be the largest on mine land, brownfield, or other degraded land.

Real estate negotiations are currently underway between the DOE and renewable energy developer Hecate Energy. Once an agreement is reached, Hecate will lead environmental reviews, including cultural resource surveys and consultations with local tribal nations, a DOE spokesperson told Canary Media. Hecate will also assess the impact of the proposed power generation on the grid to determine if any transmission upgrades are needed. These environmental and grid assessments could impact the ultimate size of the installation, according to the DOE.

The department declined to share a target timeline for the project.

In Benton County, where the Hanford Site sits, the Tri-City Development Council (TRIDEC) sees the solar installation as part of a larger transformation of the economy. The council, originally created to help diversify employment so the county was less dependent on federal funding, is planning several other renewable energy projects, along with ​“decarbonized manufacturing and industrial” projects, said Sean O’Brien, executive director at TRIDEC. ​“We very much envision that there will be a strong appetite for the electrons that this project will produce.”

Cleanup of the Hanford Site will be ongoing while the solar project moves forward into construction and operation in the coming years. ​“We can be doing both,” O’Brien said. The project itself will mostly be located on land that doesn’t require environmental remediation work, he said.

The Hanford Site is 560 square miles — about half the size of the state of Rhode Island. Since the late 1990s, workers have ​“cocooned,” or covered, seven nuclear reactors, removed 600 tons of contaminants from groundwater, and treated 32 billion gallons more. But decades of work still remain to fully remediate the site, O’Brien said. Adding solar to the site doesn’t change that, though it does at least put the land to productive use in the meantime.

Throughout the country, there are hundreds of thousands of degraded tracts of land that could make ideal locations for solar panels.

According to a 2023 evaluation by the Environmental Protection Agency, there is the potential to generate about 886,000 megawatts of solar energy from around 200,000 contaminated sites. Those sites, which include landfills, mine lands, and Superfund sites, can also come with complications though. They need to first be properly remediated, which sometimes means resolving legal liability issues that come with building on contaminated land, all of which can raise labor costs and slow down construction.

Under the Inflation Reduction Act’s ​“energy community” tax credit, clean energy projects located on brownfield sites may be eligible for additional subsidies, but Johnson said the U.S. still needs ​“to have more incentives to encourage developers to go to these sites.”

And while putting renewables on contaminated sites can’t produce all the energy that’s needed for a clean energy transition in the U.S., ​“it’s an important contribution” to meeting the country’s energy goals, he said. ​“Collectively, these opportunities could get us a large part of the way to where we need to go.”