Startup Iron Energy is taking off – thanks in part to the HSG network

The startup Iron Energy AG has developed a solution that enables energy to be stored in iron over the long term (a detailed explanation of the process can be found here). This means that surplus electricity from solar PV systems, which is available in summer, can be stored in iron storage tanks for the long term and used in winter. The storage tanks require eight times less space than lithium-ion batteries. Iron, as a storage medium, is also inexpensive and readily available.

After years of tinkering, the startup – founded by ETH graduate Dr Samuel Heiniger and HSG graduate Daniel Bloch – is now moving into the implementation phase: construction of what will be Switzerland’s largest ‘battery’ (in terms of energy capacity) to date is set to begin in Bern from 2028. According to the plan, the storage facility, with a capacity of 3 GWh, will supply a data centre from 2028.

Met an industry partner at HSG

“We developed the working concept over six years at ETH. To turn this into a project like the one in Bern, we now need a partner capable of industrial-scale construction,” says Dr Samuel Heiniger, founder of Iron Energy. The start-up found this partner in Fischer Rohrleistungs AG from Rothrist (AG).

Fischer’s managing director, Silvan Meier, and Iron Energy’s CFO, Daniel Bloch, met at HSG in autumn 2025. Meier was attending the Executive MBA programme there, a further education course for executives. Bloch gave a talk to the executives about his startup and the topic of setting up a business. This is how the two struck up a conversation and ultimately went into business together.

“This example shows just how strong the network around HSG is,” says HSG graduate Daniel Bloch. He continues to benefit from the diverse HSG community to this day when it comes to building up Iron Energy.

Further projects planned – including in St. Gallen

A test facility based on Iron Energy’s technology was operated on the ETH campus between 2023 and 2026. It was capable of storing the energy requirements of around three detached houses. A joint facility with a capacity of 20 MWh is now being built in the Basel area in collaboration with Fischer Rohrleitungs AG. Planning is also set to begin in 2026 for an underground storage facility for a residential development comprising 200 flats in Urdorf (ZH).

As, according to Daniel Bloch, preliminary agreements are in place for several storage projects in Switzerland, the young company now intends to grow further. This is one of the reasons why a funding round of 4 million Swiss francs was recently completed.

One project close to the heart of St.Gallen native Daniel Bloch is a collaboration with St.Gallen’s municipal utilities: Iron Energy is conducting a feasibility study on their behalf to assess whether it would be worthwhile to build a seasonal energy storage facility at the OLMA exhibition grounds. There is a PV system on the new Hall 1 there. Its surplus energy could be stored in the Iron Energy facility. “If it goes ahead, it would be the largest energy storage facility in the city of St Gallen as things stand,” says Bloch.