Mainova is particularly relevant for the local generation of district heating: Because heating has to be generated on site and cannot be transported over long distances. District heating is also used to supply many large companies (Frankfurt Airport, Goethe university clinic, new DFB headquarters) and the high-rise buildings in the city center with heat.
Electricity is different from district heating, however: Mainova now purchases most of the electricity it needs from outside. Because Frankfurt is hungry for electricity: the city has grown by more than 100,000 inhabitants in the past 10 years, the airport is growing and more and more data centers are being created. Electricity purchased externally can be easily transported and is also cheaper than electricity generated by Mainova itself.