In cooperation with Austria Email, commercially available hot water storage tanks are made "smart" through the use of IoT technology and securely connected to a virtual power plant via the A1 Telekom Austria mobile network. If there is too much electricity available on the grid in the form of balancing energy or if energy prices are low, the built-in GSM controller receives a signal and automatically heats up the boiler. The continuous further development of the technology also makes it possible for apartment buildings to efficiently use the photovoltaic electricity they generate themselves to heat water on site.