Ore Energy Raises $43M Series A to Build 100-Hour Iron-Air Batteries for the Grid

As Europe races to pair its growing wind and solar capacity with affordable long-duration storage, a Dutch startup called Ore Energy has emerged with a surprisingly simple answer: iron, water, and air.

Founded by materials scientist Aytac Yilmaz in Amsterdam and Delft, the company develops grid-scale iron-air batteries designed to store renewable electricity for up to 100 hours — roughly four days. In August 2026, Ore Energy announced a $43 million Series A funding round (approximately €37.3 million), co-led by Plural and HV Capital, with participation from Positron Ventures . The round brings the company's total funding to more than $61 million .

How Iron-Air Batteries Work — Reversible Rusting

The technology behind Ore Energy's batteries is an elegant twist on a familiar process: rust. During discharge, iron electrodes react with oxygen drawn from the air to release electricity, creating rust. During charging, an electrical current converts the rust back into metallic iron . This reversible rusting cycle provides a low-cost, lithium-free chemistry that avoids the supply-chain concerns tied to cobalt, nickel, and other scarce minerals .

The core materials — iron, water, and air — are abundant, inexpensive, and non-flammable, making the system safer and potentially far cheaper than lithium-ion for multi-day storage . Ore Energy claims its batteries can cost roughly one-tenth of traditional lithium-ion systems for the same storage duration .

The Largest Iron-Air Deal in Continental Europe

Even before its Series A, Ore Energy secured what is described as the largest iron-air battery deployment agreement in continental Europe. In June 2026, the company signed a 1 GWh deal with Dutch energy and telecoms supplier Budget Thuis . The agreement marks the first iron-air contract with a European energy supplier .

The deal begins with a committed 400 MWh first phase, with commercial operation targeted for 2028. Ore Energy's containerized battery architecture can be configured for durations ranging from 24 to 100 hours, allowing Budget Thuis to store excess wind and solar power for use during multi-day lulls in generation . Budget Thuis CEO Annemarie Buitelaar described the partnership as a step toward lowering consumer energy costs .

What the $43 Million Series A Will Fund

Ore Energy plans to use the new capital to build Europe's first iron-air battery manufacturing facility, fund the initial 400 MWh deployment phase of the Budget Thuis deal, and expand its manufacturing, commercial, and operations teams .

The company aims to reach gigawatt-hour-scale manufacturing capacity by 2028, with the initial facility serving as a validation of its ability to produce battery systems at utility scale . Multiple reports note the growing demand for long-duration storage driven by AI data centers, manufacturing electrification, and the broader renewable energy transition .

Why 100-Hour Storage Matters

Most lithium-ion batteries on the grid today provide 4 to 8 hours of storage — enough to cover peak evening demand but insufficient for multi-day weather events when wind and solar generation drop for extended periods. A battery capable of storing 100 hours (about four days) can smooth out these gaps, helping utilities reduce reliance on gas peaker plants and firm up renewable baseload power .

Ore Energy is not the only company pursuing iron-air storage — US-based Form Energy has been developing a similar chemistry for years — but Ore's deal with Budget Thuis and its Series A backing from Plural and HV Capital signals that European investors and utilities are taking the technology seriously as a complement to lithium-ion .