US Army deploys its first floating solar array

FORT BRAGG -

Floating solar had a moment in the spotlight over the weekend when the US Army unveiled a new solar plant sitting atop the Big Muddy Lake at Fort Bragg in North Carolina. It’s the first floating solar array deployed by the Department of Defense, and it’s part of a growing current of support in the US for “floatovoltaics.”

The army says its goal is to boost clean energy, reduce greenhouse gas emissions, and give the nearby training facility a source of backup energy during power outages. The panels will be able to generate about one megawatt of electricity, which can typically power about 190 homes.

The installation, the largest in the US Southeast, is a big win for floatovoltaics, which have yet to make a big splash in the US. They only make up 2 percent of solar installations annually in the country, according to Duke Energy, which collaborated with Fort Bragg and the renewable energy company Ameresco on the project.

Upfront costs for floating solar have typically been slightly more expensive than for its land-based counterparts. The panels essentially sit on a sort of raft that’s tethered to the bottom of the body of water. But floatovoltaics come with unique benefits. Hotter temperatures make it harder for solar panels to produce as much power from the same amount of sunshine. Luckily, sitting atop water has a cooling effect, which allows the panels to generate more electricity than panels on land. That makes floating solar more efficient and makes up for higher installation costs over time.

And while solar in general has already become the cheapest electricity source globally, it’s pretty land-hungry. A solar farm might take up 20 times more land than a fossil fuel power plant to produce a gigawatt of electricity. Solar projects in the US have already run into conflict with some farmers who want to use the same land, for example, and with some conservationists worried about the impact on desert ecosystems.