It is probably the simplest and most modern solution to cut by half your bills. Here, no solar collectors on the roof, but rather a hot water tank and heat pump combined together. Depending on the models, the heat pump captures the energy from the ambient air (all-in-one unit installed in an unheated technical room of at least 20 m²) or from the outdoor air (two-part product or split system equipment) to give it back to the tank water.
