US Army deploys its first floating solar array

Image: Ameresco

Over the weekend, the US Army unveiled a new solar plant on top of the Big Muddy Lake at Fort Bragg in North Carolina. The Department of Defense is the first to deploy a floating solar array.

The army wants to boost clean energy, reduce greenhouse gas emissions, and give the training facility a source of backup energy during power failures. The panels will be able to generate a small amount of electricity, which can be used to power 190 homes.

The installation is the largest in the US Southeast and is a big win for floatovoltaics. According to Duke Energy, they make up 2% of solar installations in the country.

The upfront costs for floating solar have been more expensive than for land-based ones. The panels are attached to a raft that is tied to the bottom of the water. Floatovoltaics have unique benefits. It's hard for solar panels to produce the same amount of power when the temperature is hot. The cooling effect of the water allows the panels to generate more electricity than on land. It makes floating solar more efficient and less expensive to install.

Solar is the cheapest electricity source in the world, but it is also land-hungry. A solar farm is 20 times larger than a fossil fuel power plant. Solar projects in the US have run into conflict with some farmers who want to use the same land, and with some people who are concerned about the impact on the desert environment.

Some of the tensions could be avoided by floatovoltaics. They are more common on human made bodies of water in the US. These are easier to build on and are less likely to have a big impact on the environment. As researchers pointed out in a recent commentary in the journal Nature, just 10 percent of the world's hydropower can be covered with floatovoltaics. It's an added benefit that the panels reduce the amount of water in the air. California is experimenting with solar panels on irrigation canals.

The solar industry could gain a stronger foothold in the US. Less than 3% of the US's electricity mix is made up of solar. In the US, wind power is three times more powerful than electricity. In places with less abundant land, floating solar has made a splash.

To meet US and global climate goals, all renewable energy needs to be scaled up dramatically. The goal of the Biden administration is to get to a 100 percent clean energy power grid by the year 2035. Under the Paris climate accord, that is what is required to achieve targets.

The US Department of Defense releases more greenhouse gas emissions each year than any other nation. The new floating solar plant at Fort Bragg needs to be used as a source of clean energy. The US Army has a plan to reach net zero emissions by the middle of the century.

Climate change is something the army wants to address. Climate impacts will disrupt Army activities for the foreseeable future. Potential power outages are also included. If a storm knocks out power to the area, Fort Bragg has a 2-megawatt battery that can be used. The army wants to have enough renewable energy generation and battery storage capacity by the year 2040.