The SOLID student team at TU/e is working on a technology that stores energy in iron pellets, which can be converted into hydrogen at a later stage. The team is working on a 2.5 MWh pilot plant, which is equivalent to the output of around 2,000 solar panels.
The student team’s technology uses hydrogen to convert rust (iron oxide) into iron, in which energy is stored. If this iron later comes into contact with steam, hydrogen is produced again. This creates a closed cycle.
No energy loss during storage and transport
The team highlights various advantages. For example, iron can be stored and transported easily and quickly, including in the form of iron pellets. Furthermore, energy can be stored for months without any loss.
The technology has been under development by the student team since 2016, with hundreds of students having contributed to the project.
Scalable
Using the pilot plant, SOLID aims to demonstrate that its energy storage technology is scalable. The team hopes this technology will contribute to making industry more sustainable.
The pilot plant is expected to take one and a half to two years to complete. It is an iron-based hydrogen storage system that will be housed in a 20-foot shipping container. The team then intends to test the system in practice at several locations. The focus will be on performance, reliability and applicability in industrial environments.
SOLID team manager Sam Liebregts: “We’re moving from proof of concept to practical application. It shows that student teams can play a significant role in the energy transition. We’re now taking a giant step towards making a real impact. As far as we know, this technology is not being developed anywhere else in the world on this scale, and certainly not with such concrete steps towards actual implementation.”
Iron powder as fuel
The development of this technology previously led to the establishment of RIFT (Renewable Iron Fuel Technology). This spin-off focuses on industrial applications of iron powder as a fuel. The powder is burnt in a boiler, generating a great deal of heat without direct CO₂ emissions. The iron oxide remaining after combustion is then converted back into iron fuel using hydrogen. The system is therefore circular.
In June 2025, RIFT signed its first contract with an industrial partner that will be using the company’s iron fuel. Kingspan Unidek, a supplier of insulation solutions based in Gemert, will thus be the first to implement iron fuel commercially and operationally in an industrial setting. The so-called Iron Fuel Boiler is due to be operational in 2028.
