Design, construction and test of a heat-insulated pit-type heat store containing 30,000 cum hot water at temperatures 90 C

The construction of a very large pressureless hot water displacement storage tank in the ground in or near heavily populated areas, taking into account safety and environmental factors, and whether an economic operation using the system as a seasonal store over a whole year can be expected for water storage temperatures of at least 90C was studied. Several design concepts for earth and container stores were compared. A cylindrical steel storage basin represents the best solution from a technical and economical point of view, but no decision to proceed was taken.