Heliac is a fast-growing renewable energy company providing patented solar thermal technology and innovative heat storage solutions for emission-free energy.
Led by technical founders, the company has built solar fields and storage facilities for energy majors E.ON and Norfors and is targeting the rollout of their technology across Europe.
Realising the global need for affordable energy storage, Heliac expanded from solar power generation into heat storage, developing the RockStore system.
The company has raised €13.5m to date and is currently raising funds on Seedrs to fund further growth.
Heliac’s RockStore thermal storage technology uses rocks such as granite to store surplus heat from sustainable energy sources for later use – either for heat applications or electricity.
Speaking on a recent podcast with UK Investor Magazine, Michael Lindegaard, CFO at Heliac, said the cost efficiencies associated with their storage technology make their solution an attractive alternative to lithium batteries or pumped hydro.
The RockStore uses mineral oil instead of water for heat transfer, allowing compact and cost-effective components. Solar or renewable electricity heats the oil, which is stored in insulated tanks with granite. When heat is needed, cold oil is heated to generate electricity.
Heliac CEO Henrik Pranov is delighted with the technology, proven capable of storing heat for months. He emphasises RockStore’s potential to support the energy transition.
A key focus is balancing engineering and costs. Although higher efficiency is possible, Heliac prioritises feasibility. The expected cost is around 200 Danish kroner per kWh – highly competitive compared to alternatives.
“We are constantly trying to strike a good balance between engineering efficiency and cost-effectiveness. We know that we could achieve a much higher electrical-to-electrical efficiency than we’re aiming for, but it would increase the price,” says founder and CEO Henrik Pranov.
“In the end, the electrical-to-electrical efficiency doesn’t matter as much to us because we primarily use it for heat projects with the added benefit of supporting the electrical grid.”
The unique oil heat transfer allows thinner, cheaper tanks, further demonstrating the cost efficiencies of the technology.
Heliac’s vision is larger commercial-scale storage by 2025. With continued streamlining and regulatory support, their innovative RockStore technology shows promise for affordable renewable energy storage.
