Google is constructing a variety of renewable energy sources in Minnesota—featuring the world’s largest battery system capable of delivering power for an impressive 100 hours

This week, [a company] announced it is developing a new data center complex south of Minneapolis, which will be powered by a veritable utopia of clean energy: abundant wind, solar, and, notably, the world’s largest battery storage system.

While most storage systems typically provide power for four hours, or increasingly eight hours, the Form Energy technology that Google will use is designed to deliver up to 100 hours of power at once. Form’s iron-air battery technology provides multi-day durations, meant to keep the power flowing during extended severe weather, peak summer demand, or even a particularly cloudy week that reduces solar power.

The concept is that renewable power, when combined with shorter and longer duration batteries, can finally address the reliability concerns of critics and provide a comparable level of baseload power to that from fossil fuel and nuclear generation.

“This is the largest energy storage project announced globally,” stated Form co-founder and CEO Mateo Jaramillo. “It firmly validates the business case for what we refer to as multiday-duration storage.”

Form, a nine-year-old company, is opening its Form Factory 1 manufacturing hub in West Virginia this year and is now set to expand. Jaramillo, an alumnus, said the plan is to take the company public in the “relatively near term,” likely next year. “For the size of the company we are becoming and the types of deals we’re making with our customers, being a public company is advantageous for us.”

Importantly, Form’s partnership with Google and a Minneapolis utility for the Pine Island data center complex could be a pivotal moment for the emerging long-duration battery industry. Google is the first hyperscaler to contract for this battery technology.

Standard, short-duration lithium-ion batteries have advanced rapidly on the U.S. grid. In 2020, the total installed battery storage capacity was about 1.5 gigawatts. However, this year alone, the Department of Energy projects 24.3 gigawatts of new battery storage installations—more than twice new wind power and nearly four times new gas-fired generation capacity.

While lithium-ion technologies are derived from electric vehicle chemistries, Form’s technology focuses on heavier, less-efficient iron-air batteries that are, notably, much cheaper than lithium-ion. This makes the technology suitable for long-duration electricity storage, but definitely not for electric vehicles.

The battery technology operates through a reversible rusting process. Essentially, oxygen pumped into the cells causes iron to oxidize and rust, releasing electrons. These batteries operate at about one-tenth the cost of lithium-ion, enabling the long durations.

The Google-Xcel partnership for the Minnesota data center project involves constructing 1.4 gigawatts of wind power, 200 megawatts of solar, and a 300-megawatt Form battery system. The 300 megawatts, scheduled for installation in 2028, can power over 200,000 homes when deployed.

Google, Xcel, and the state are using a new green tariff agreement called the Clean Energy Accelerator Charge, which allows Google to choose its own bundled renewable energy mix as long as it covers the costs and doesn’t pass charges on to Minnesota residents. According to The Information, Massachusetts-based Form will be paid nearly $1 billion for its contributions.

How it all works

Mateo Jaramillo, a battery storage expert and former vice president at Tesla, left in 2017 because he felt he had reached the end of his journey there, wanted to stay at the “cutting edge” of the technology, and wanted to maintain a healthy family life.

“You’ve probably heard, it’s a fairly intense place to work,” he joked.

Jaramillo and his colleagues started experimenting with iron-air technology concepts and determined there was potential to operate similarly at a larger gas-fired power plant. These clean energy batteries would compete with so-called peaker gas plants, which are quickly started and stopped as needed to meet increasing power demand.

This led to the creation of Form. Battery technologies had been gradually expanding from 15 minutes to an hour, and now to today’s four- and eight-hour solutions.

“We never agreed with that viewpoint,” Jaramillo said. “We started the company with the idea that if you could find a cheap enough chemistry, you could have a much longer duration, roughly four to five days.”

Short-duration batteries pair with renewables to fill the gaps when the sun isn’t shining for solar or the wind isn’t blowing—often, wind and solar work well together because wind power is usually strongest at night. The long-duration batteries from Form and its smaller competitors are designed for multi-day weather or demand events that lithium-ion batteries can’t handle.

“That 100 hours sounds simple and like a nice, attractive round number, but it’s really well-supported by the numbers,” Jaramillo said. “Think about a polar vortex, a heat wave, a hurricane, or a sandstorm. Any place in the world has roughly a four-to-five-day weather pattern that drives that. These events are spread out over a few occurrences throughout the year—more or less 100-hour periods.”

He argued that incorporating Form’s batteries with renewables can get data center projects approved much faster because utilities and regulators don’t have to worry about power generation gaps straining the grid, since everything is essentially self-sufficient.

“That 100-hour duration is what’s needed to provide true, stable capacity to the system,” Jaramillo said. He explained that without this, data center projects would need to build excess renewables and short-duration batteries to compensate.

Form’s West Virginia factory will open later this year and will scale up to manufacturing 500 megawatts of battery power per year by the end of 2028. Jaramillo said the tentative plan is to continue expanding from there.

Meanwhile, at the end of last year, Form started installing its first 100-hour batteries to the grid in a small 1.5-megawatt project with Great River Energy in Minnesota.

Form has several other smaller project installations scheduled between now and 2028, including another 10-megawatt project in Minnesota with Xcel, 10 megawatts in Colorado with Xcel, a project in California with PG&E, 15 megawatts with Georgia Power, 5 megawatts in Virginia, 10 megawatts in New York, and its second-largest project after Google—85 megawatts in Maine.

“At the same time, we knew the market would develop as slowly as the technology,” Jaramillo said. He said market demand, technology, and manufacturing capabilities are now aligning.