The deep subsurface will play a major role if the Netherlands wants to use sustainable energy on a large scale. By storing wind and solar energy in energy carriers such as hydrogen and compressed air, we can ensure there is enough energy available even on cloudy, calm days. The subsurface offers space in empty gas fields, salt caverns, and aquifers (porous, water-bearing rock in the subsurface) to store other substances, such as renewable fuel and heat, in sufficiently large amounts. We already store large amounts of gas for heating during the winter. Read more about underground energy storage on the NLOG website.