US: World’s largest 8,500 MWh capacity battery to be built in Maine

Somerville, Massachusetts-based Form Energy plans to convert the former paper and pulp mill site in Lincoln, Maine, to one housing the world’s biggest battery installation, injecting up to 85 MW of power into the grid at a time. While other energy storage solutions, such as pumped hydro plants, have much bigger capacity, this will be the first installation at such a scale using battery technology alone.

As the world turns greener with the increased adoption of wind and solar power plants, there is also an urgent need for large-scale energy storage solutions that can store excess renewable energy. While pumped hydro storage can deliver such capacities, it involves a massive construction process and is not feasible in all locations.

Lithium-ion batteries are currently the only go-to solution for versatile energy storage. However, the technology is expensive, has limited hours of output, and also comes with a risk, especially in areas with extreme temperatures. Form Energy uses iron-air technology, which is one-tenth as expensive to deploy, can provide 100 hours of energy output, does not catch fire, and is also easier to recycle.

How does an iron-air battery work?

Iron-air batteries use simple and ubiquitous materials: iron, water, and air. It uses the reversible principle of rusting for its operations and a non-flammable water-based electrolyte.

When the battery discharges, it uses oxygen from the air to convert metallic iron to iron oxide or rust. During the charging process, iron oxide is converted back to iron, and oxygen is given out.

An iron-air battery module is about the size of a washer-dryer set. It contains about 50 cells, each about three feet tall, submerged in the electrolyte. Multiple modules are then placed in enclosures that protect them from the elements and can be further grouped together into megawatt-scale power blocks.

Form Energy will use its power packs to store 85 MW of power with a discharge level of 100 hours, making it the biggest battery in the world.

Building the world’s largest battery

So far, Form Energy’s list of completed projects includes battery packs with a few MW of power output, built largely for utility companies. In Lincoln, Maine, the company is foraying into a project independently. In addition to setting a record, it will also be an energy scarcity problem faced by regional states.

According to Canary Media , the region has limited supplies of fossil gas because environmental protections prohibit the construction of new pipelines.  Therefore, the region is dependent on liquified natural gas to meet its increasing energy demand.

However, a protectionist law prevents the region from buying American gas, instead requiring it to procure it from the international gas markets. Even after securing supplies in the high-volatility pricing, the region faces another hurdle during winter months since the fuel is first dedicated to heating needs. To overcome the shortages, the region burns oil instead, increasing its emissions.

Form Energy’s installation will help store renewable energy from wind and solar parks and also help meet the grid’s needs when power output is low. Since this also prevents the usage of gas reserves, it is a win-win situation for the residents of the region.

The Department of Energy (DOE) has allocated $147 million to building the project, and the world’s largest battery is expected to come online by 2028.