A new heating and cooling concept for residential buildings and areas is being investigated, which uses PVT collectors and an insulated ground storage tank open at the bottom as a buffer and long-term storage. In addition to the heat from the PVT collectors and the ground, excess space heat is also buffered in the ground storage tank and, if necessary, recooled during the night via the PVT collectors. In addition to use in individual buildings, the system can also be connected to form a heating and cooling network, as well as retrofitted with additional buildings. In terms of overall energy efficiency and a grid-serving connection (e.g. demand-side management), a great deal of potential can be tapped in this way. This system could be an alternative to commercially available systems because it is able to provide both the heating required today and the air-conditioning required in the future without retro-fitting.