Google Data Center to Run on World’s Largest 100-Hour Battery System
Published · 5 min read
Google announced plans to power a new Minnesota data center with the world’s largest battery storage system, marking a major breakthrough in renewable energy reliability.
The tech giant signed a deal with utility Xcel Energy to build a massive facility in Pine Island, Minnesota, backed by 300 megawatts of iron-air battery storage that can discharge power for 100 continuous hours. The project also includes 1,400 megawatts of wind power and 200 megawatts of solar generation, set to come online in 2028.
The agreement demonstrates that fully renewable, reliable power for energy-intensive operations is no longer theoretical. It’s becoming real.
A Battery That Works Like Rust
The system at the center of the deal comes from Form Energy, a Massachusetts-based startup that invented a battery using one of Earth’s most abundant materials: iron.
The technology works through reversible rusting. Iron pellets oxidize when exposed to oxygen, generating electricity. When the battery recharges, an electrical current converts the rust back to iron.
Unlike lithium-ion batteries that typically last four to eight hours, Form Energy’s iron-air system can release power continuously for more than four days. That solves a critical problem: what happens when the sun doesn’t shine and the wind doesn’t blow for extended periods.
The company targets a system cost below $20 per kilowatt-hour, potentially one-tenth the cost of lithium-ion batteries for long-duration storage. Iron is dramatically cheaper than the cobalt and nickel used in conventional batteries.
Manufacturing at American Scale
Form Energy produces the batteries at its Weirton, West Virginia facility, which began commercial production in 2024.
The plant is on track to reach 500 megawatts of annual production capacity by 2028 and will employ at least 750 people across approximately 850,000 square feet of manufacturing space.
The company secured $405 million in Series F financing in 2024, with investors including Bill Gates’s Breakthrough Energy Ventures. It also received up to $150 million from the U.S. Department of Energy to support the West Virginia facility.
Each battery module is roughly the size of a side-by-side washer-dryer set. The modules contain approximately 30 one-meter-tall cells filled with iron and air electrodes, along with a water-based, non-flammable electrolyte.
Why This Matters Now
U.S. data centers consumed an estimated 183 terawatt-hours of electricity in 2024, representing approximately 4 percent of the nation’s total electricity consumption.
By 2030, that figure is projected to double to approximately 426 terawatt-hours, equivalent to the entire annual electricity demand of Pakistan. The surge is driven by artificial intelligence systems like ChatGPT and Google’s Gemini, which require vastly more power than traditional computing.
A single ChatGPT query consumes roughly five times more electricity than a standard web search. A typical AI-focused data center consumes as much electricity annually as 100,000 households, while newer facilities under construction are expected to use 20 times that amount.
Without solutions like long-duration batteries, meeting this demand while maintaining climate commitments would be nearly impossible. In Virginia, data centers consumed 26 percent of total electricity supply in 2023, straining infrastructure to the breaking point.
A New Model for Clean Power Deals
The Google-Xcel partnership is designed to protect Minnesota residents from bearing infrastructure costs.
Google will cover all costs associated with the new service and required grid upgrades. The agreement uses a framework called the Clean Energy Accelerator Charge, which allows the company to select its own clean energy mix while ensuring no costs are passed to existing ratepayers.
The total clean energy buildout includes the 1,400 megawatts of wind, 200 megawatts of solar, and 300 megawatts of battery storage. The resources will advance Xcel Energy’s current energy mix of 70 percent carbon-free electricity toward an even cleaner grid.
Google also committed $50 million to Xcel’s Capacity Connect Program, which will build a distributed network of smaller batteries across the utility’s system to strengthen grid reliability.
The electric service agreement will be filed with the Minnesota Public Utilities Commission for formal approval in the coming weeks.
Multi-Day Storage Becomes Essential
The 100-hour duration specifically addresses weather patterns that naturally cluster into multi-day events.
Polar vortexes, heat domes, hurricanes, and other extreme weather events typically last three to five days. Seasonal variations in renewable generation also create demand for systems that can store energy across extended periods.
Current short-duration batteries excel at smoothing hourly and daily variations but are economically infeasible for backing up renewable generation across multi-day weather events. Traditional natural gas peaker plants have historically filled this role, but these facilities emit significant greenhouse gases and operate at extremely high costs.
Form Energy CEO Mateo Jaramillo told Fortune that the deal “definitively confirms the business case for what we call multiday-duration storage.”
With the battery paired with wind and solar, data center projects can be approved and built more quickly because utilities and regulators no longer need to account for power generation gaps stressing the grid.
What Comes Next
Form Energy has a robust project pipeline extending through 2028 beyond the Google installation.
Scheduled deployments include a 10-megawatt project with Xcel in Colorado, a California project with PG&E, a 15-megawatt installation with Georgia Power, a 5-megawatt system in Virginia with Dominion Energy, a 10-megawatt project in New York, and an 85-megawatt system in Maine.
In late 2025, the company began installing its first 100-hour batteries to the grid through a small 1.5-megawatt pilot project with Great River Energy in Minnesota, providing real-world data on system performance.
The success of the Minnesota project will likely inspire similar partnerships across the U.S. and globally. Microsoft has announced intentions to purchase 10.5 gigawatts of renewable energy, while Amazon, Meta, and other technology companies are actively seeking similar deals.
Google has set an ambitious goal to operate on 24/7 carbon-free energy across all operations by 2030. The Minnesota project represents a major step toward achieving that target without relying on fossil fuel backup.
The 300-megawatt iron-air battery will store 30 gigawatt-hours of energy, enough to power more than 200,000 homes when fully discharged. More importantly, it will prove at commercial scale that multi-day energy storage works, that it is affordable, and that it makes renewable energy as reliable as the fossil fuel systems it replaces.
References:
- Fortune: Google Building World’s Largest Battery System
- Energy-Storage.news: Google Minnesota Data Centre Energy Deal
- Form Energy: Iron-Air Battery Technology
Jonas Muthoni is Editor-in-Chief of Microgrid Media, where he oversees reporting and analysis on microgrids, energy storage, distributed energy resources, data center power demand, grid modernization, resilience, renewable energy, and electricity policy and markets. His work focuses on the infrastructure, technologies, and regulatory developments reshaping the power system.
As Editor-in-Chief, Jonas leads Microgrid Media’s editorial strategy and standards, including story selection, source verification, technical accuracy, and the development of original reporting and analysis. His coverage draws on regulatory filings, government records, utility and company disclosures, technical documentation, and independent industry sources to explain significant developments across the evolving energy system.
