Martin Bloemendal is a specialist in geothermal energy storage and works on various studies on utilization of sustainable heat by means of seasonal storage in the subsurface. Martin always considers the system as a whole, which means not only the source of heat or cooling capacity, but also consumers and the required facilities to utilize the available heat. That is why he also has extensive knowledge of related and complementary techniques. He does not focus on the technical aspects only; he also works on organizational and policy-based issues concerning sustainable heating and cooling. Martin has a clear vision for the use of the subsurface with geothermal energy. He combines two part-time jobs at KWR and Delft University of Technology that allows him to come up with the proof of concept of new solutions, and also implement them in pilot projects. Martin is also on the board of the sector association BodemenergieNL, where his tasks are to address legal matters and the research agenda for geothermal energy storage.