Google's power supply plan for its Minnesota data center includes a planned 300MW/30GWh iron-air energy storage system with a design discharge duration of 100 hours, according to reporting from 36Kr. Utility Xcel Energy plans to deploy Form Energy's systems so they can charge when power is abundant and return electricity to the grid when needed, supporting both the data center and the surrounding power system.
A 100-hour asset on the utility side of the meter
The configuration is notable because the storage is described as supporting the wider grid as well as the load. Rather than sizing storage for a few hours of backup, the plan pairs a very large energy capacity with a comparatively modest power rating — the ratio that defines long-duration storage.
The Minnesota plan pairs 300 MW of power with 30 GWh of energy, a 100-hour design discharge duration.
Data-center demand is the new load-growth story
The IEA expects global data-center electricity consumption to rise from 485 TWh in 2025 to about 950 TWh by 2030. If bottlenecks are not resolved, roughly 20% of planned data-center projects could face delays. In 2025, the technology sector accounted for about 40% of global corporate renewable PPA capacity signed.
That combination — very large new loads plus a preference for renewable supply — has pushed developers toward firming options that extend beyond lithium-ion's typical four-hour block.
Multi-day resilience arguments
The California Energy Commission has noted that multi-day storage can provide reliable service during prolonged low-renewable-generation periods, extreme weather and wildfires. Iron-air's proposition rests on the reversible oxidation of iron: the battery discharges as iron oxidizes and charges by reducing iron oxide back to iron, using a widely available, low-cost active material.
Fraunhofer UMSICHT researcher Marvin Kosin cites material price and availability as the main advantages of iron-air for stationary storage. World Steel Association data illustrates the scale gap: 2025 global crude steel output was about 1.849 billion tonnes versus global lithium mine output of roughly 290,000 tonnes.
For now, the Minnesota system sits in the planned category rather than the commissioned one. Xcel Energy's deployment schedule and Form Energy's manufacturing scale-up will determine the timeline, and the project's regulatory treatment will be watched as a template for pairing LDES with large industrial loads.
This article was assisted by AI analysis. Please refer to the original source for official information.