Europe is betting big on a battery that runs for four days

A Dutch company called Ore Energy has struck a deal to supply a new kind of grid battery in the Netherlands, and it just raised $43 million to help build it. The battery uses iron, water, and air instead of lithium, and it can store electricity for up to 100 hours, versus the few hours typical of home or grid lithium-ion batteries. The idea is to soak up extra wind and solar power when it's abundant and cheap, then release it days later when the weather turns and renewable output drops. Dutch energy supplier Budget Thuis has committed to 1 gigawatt-hour of this storage, starting with a 400-megawatt-hour first phase due by 2028.

This is grid-scale infrastructure, not something you'd install at home, so it won't show up as a product you can buy. But it points to where the broader energy system is headed: utilities storing cheap renewable power for days at a time instead of hours, which over time could mean more stable electricity prices and less reliance on fossil-fuel backup plants during calm, cloudy stretches. The batteries are bulkier and less efficient than the lithium-ion type, but their simple, cheap materials make them attractive for this kind of long-haul storage.

For now, this is a European development, tied to the Dutch grid, with no direct program or rebate for U.S. homeowners. It's worth watching as an early sign of how grid operators plan to handle the ups and downs of wind and solar power in the years ahead.