Parkstad is planning to power most of its electrical grid by solar energy, resulting in an intermittent power supply. One of the methods to solve this intermittency is to create facilities for energy storage. The landscape differs from the rest of the Netherlands by its hilly profile. The most important difference is presence of a large subterranean infrastructure which is a relic from the mining past. This vast infrastructure holds potential for energy storage. Energy storage demand exists on three levels. Daily storage demand, inter seasonal storage demand and incidental storage demand could benefit from energy storage among other solutions. The actual methods to achieve this energy storage are mechanical, electrochemical, chemical and thermal. For Parkstad compressed air storage, underground pumped hydro and gravitational storage hold potential.