In cooperation with Austria Email, commercially available storage water heaters are made "smart" by using IoT technology and securely connecting them to a virtual power plant via the A1 Telekom Austria mobile network. In case there is too much electricity available on the grid in form of ancilliary service or if energy prices are low, the built-in GSM controller receives a signal and automatically heats up the boiler. The constant development of this technology also makes it possible for apartment buildings to efficiently use photovoltaic electricity generated on site to heat water.