Student innovator aims to harness energy from freezing water

Could the energy released when water freezes become a future energy source? Viktor Björklund believes so. He has recently applied for a patent for his idea and is now being named Student Innovator of the Year 2025.

“Everyone’s heard of water pipes bursting in winter, there’s an enormous amount of energy in that pressure if you can find a way to harness it,” says Viktor Björklund, who has just graduated with a Master’s degree in Mechanical Engineering.

As early as the 1980s, researchers at Luleå University of Technology explored ways to extract energy from freezing water. The challenge, however, was that it took even more energy to melt the ice again, and the research stalled. Now, Viktor Björklund has come up with a way to make the process work without melting the ice.

“I’ve applied for a patent, so I can’t reveal exactly how it works,” he explains. “What I can say is that I’ve designed a concept that allows freezing to take place continuously, without the need to thaw the ice.”

Cold climate for green electricity

The idea is to take advantage of the cold winter climate to produce green electricity when other energy sources perform poorly, such as during the dark northern winters when solar panels are less effective. When it’s bitterly cold and the demand for electricity is highest, Viktor Björklund believes his innovation could make a real difference. He has already received funding for the next step, developing a prototype, through a grant from the XO Foundation.

Researcher Bo Nordell calculated back in the 1980s that one cubic metre of freezing water could, under the right conditions, generate the equivalent of 6 kWh of energy. He even built a small go-kart powered by freezing water. Viktor Björklund has been in contact with Nordell, who is still an active researcher.

“We’ve met, and he’s pleased that someone is continuing the work,” says Viktor. “I really believe in this, and I’m thinking big. My dream is to build a one-megawatt power plant.”

Education that provides tools for innovation

Viktor Björklund is already an entrepreneur, running a distillery business in Brändön. He plans to take the new innovation forward through another company.

“I actually had the idea before I started studying engineering, but now I’ve got the tools to take it further,” he says. “I don’t think I’ll work as a salaried engineer, I want to focus on my own businesses and innovations. The education has been incredibly valuable, and receiving this award is a fantastic way to round it off. Now I’m hoping to find more partners to help turn this idea into reality.”

Student Innovator of the Year 2025

Motivation – Student Innovator of the Year 2025:
The award winner has, through strong personal drive and initiative, taken an innovative idea to a calculated prototype stage while also securing funding for further development and potential commercialisation. The solution is based on harnessing energy from the expansion of water as it freezes and has the potential to contribute to sustainable green transition in cold climates.

The award will be presented on 4 November at the Inspiration Day 2025.

• Do you also have an idea you want to realise? Get in touch with the university’s innovation advisers here