Google’s new 1.9GW clean energy deal includes massive 100-hour battery

Google announced Tuesday that it will build a data center in Minnesota backed by 1.9 gigawatts of clean energy, including a 300-megawatt giant battery made by startup Form Energy.

The new data center, Google’s first in Minnesota, will be located on Pine Island, about an hour southeast of Minneapolis.

The technology company is partnering with Xcel Energy to build 1.4 gigawatts of wind power and 200 megawatts of solar power. Both will feed the Form battery, which will be able to deliver its rated power for 100 hours. At 30 gigawatt hours, it will be the largest battery in the world, helping the data center run on clean energy for longer.

Such long-lasting batteries help renewable energy sources continue to provide power at night or during puberty, “boosting” the energy source, as experts call it. Grid-scale lithium-ion batteries do this already, albeit for a short time.

Form Energy batteries are not like other grid scale batteries. While today’s standard grid-scale battery uses lithium-ion technology recycled from chemicals used by the automotive industry, Form batteries store energy by corroding and removing metal.

When oxygen from the air flows over the metal cells inside the battery, it corrodes the metal, generating electricity in the process. To charge, the electrical current removes the rust, returns it to the metallic iron and removes oxygen from the system, which is released from the battery.

As battery chemistry goes, the iron-air cells of the Form are heavy and inefficient. Standard iron batteries can only deliver 50% to 70% of the energy used to charge them, compared to more than 90% for lithium-ion batteries. But for all their downsides, they come with one huge upside: they’re incredibly cheap. The form says that 1 kilowatt-hour of storage will eventually cost only $20 using their technology, which is at least three times cheaper than lithium-ion batteries.

The new project also introduces a wonky penalty structure in Minnesota that aims to help utilities use clean technology without abusing their regulators, forcing utilities to use the cheapest power source.

Google first developed the concept in Nevada, where it purchased energy from advanced geothermal startup Fervo. Also called the “clean transition fee” or the “clean energy accelerator fee,” the agreement between Google and Xcel allows the utility to accept projects that are not considered risky by regulators, the technology company pays the fee to ensure that ordinary taxpayers are not left holding the bag.

Solar and wind are both proven technologies, but Form’s iron-air batteries are still relatively new. The first startup battery is currently being installed in Minnesota and partnered utilities Great River Energy, and will store 150 megawatt hours for 100 hours, sending 1.5 megawatts to the grid during peak hours.

Form makes its batteries at a factory in West Virginia. The company has raised $1.4 billion so far, according to PitchBook data.