Innovation in the Earth's crust secures energy
Heating and cooling account for half of the global energy consumption. The availability of clean, decarbonized renewables is a challenge when developing sustainable energy solutions. In the rock beneath the Earth's crust lays a sustainable solution to the problem.
– For 4,5 billion years, energy has been stored as heat in the rocks of the Earth. We now mimic this near the surface to create energy security, says Johan Hogmalm, Associate Professor and Geologist at the University of Gothenburg.
His research in geothermal energy recently led to an innovative solution of long-duration energy storage located under our feet, called Heat Vault. The solution is now being commercialized in a spin-off company that Johan Hogmalm co-founded with Dr. Harry Bradbury, a former Yale University geology professor turned successful serial founder. The company has ambitious goals to support the energy transition to net zero.
– Being able to store energy between seasons is key to moving the energy transition forward, Johan Hogmalm says.
– The rollout of solar and wind power has been so efficient that massive amounts of energy are now produced when it isn’t needed. This results in negative electricity prices and curtailment, which is not sustainable. Instead, we need low cost and scalable storage solutions.
Storing and recovering heat
Heat Vault is a patented solution that allows recovery of waste heat from industry and excess electricity from solar and wind power. The waste heat is used to heat up large volumes of rocks to high temperatures via multitude of deep boreholes. The heat can be stored for long periods, up to years, and then be recovered when needed as district heating, industrial process heating and even for electricity generation by turbine technology.
The Heat Vault solution uses natural rocks, which in contrast to Li-ion batteries doesn’t require mining, processing and factories to produce. Therefore, Heat Vault can be built at a fraction of the cost and environmental impact of batteries and other storage solutions. This in turn allows the scale and duration of storage needed for a 100 per cent renewable energy system.
Johan Hogmalm is convinced the most effective way to ensure a stable supply from intermittent renewables is to pair their expansion with large-scale, long-lasting energy storage solutions. The idea is to let these storage systems step in and deliver heat, power and even cooling when renewable sources fall short - day or night and without interruption.
New milestone reached
Last year a milestone was reached as Heat Vault completed a 1GWh demonstration storage in western Sweden and the solution was validated. Up next are the first commercial projects and building a larger team.
– Introducing innovations and new solutions to the market is never easy. But it is very rewarding to see how our research is starting to be of use and contribute to solving a major societal problem.
Contact: Johan Hogmalm, johanh@gvc.gu.se
