Sand Battery from Finland – for energy storage, district heating, and electricity generation

The world’s largest sand battery, a 100 MWh thermal energy storage project, is now operational in Pornainen, Finland. Built by Polar Night Energy, the battery stores excess renewable energy as heat in sand, which is then used to heat homes and buildings. This innovative project aims to significantly reduce carbon emissions and reliance on fossil fuels for district heating. 

This new kind of sand battery stores clean energy not in chemicals or metals, but dry sand (construction grade or other suitable granular material) and utilising large, insulated containers / silos. During periods of excess renewable energy production, the energy is used to power a resistive heat coil buried deep inside the sand heating it to high temperatures (500-600 Celsius) and thanks to its low conductivity and high density, it retains the heat for weeks or even months. When heat is needed, the stored thermal energy can be extracted through air channels to power district heating systems, warm buildings or generate electricity for hybrid systems. 

The Pornainen sand battery represents a significant step forward in the development and deployment of large-scale energy storage solutions using sustainable materials and technologies. It demonstrates the potential of sand batteries to play a crucial role in the transition to a more sustainable energy future. 

The tech: https://polarnightenergy.com/sand-battery/

Info from Polar Night energy: https://polarnightenergy.com/news/worlds-largest-sand-battery-now-in-operation/