© Federal Ministry for Economic Affairs and Energy
Technological diversity for a successful heat transition
A wood chips boiler towering 13 metres high and having a capacity of 5 megawatts (MWs) is the heart of the new CHP plant in Memmingen, Bavaria, which was inaugurated in the presence of Federal Minister Katherina Reiche on 12 March. Paired up with solar-powered heat pumps and – in future – industrial waste heat, Memmingen is about to gain an exemplary, technology-neutral district heating network run by regional economic stakeholders.
€11 million of the total €30 million investment comes from the federal funding for efficient heat networks. The Federal Government uses this instrument to support the new construction of heat networks, provided that at least 75% of the heat used comes from waste heat or renewables. There is also a contribution of up to 40% of the investment costs towards an incremental expansion or conversion of existing heat networks to work towards greenhouse gas neutrality.
Innovative heat network with 4 pipelines for the use of industrial waste heat
The electricity powering the heat pumps in Memmingen comes from PV installations close to the nearby airport. The wood chips used to power the boiler are made of logs from the region. The installation runs entirely on renewable energy. The heat network has been planned in a particularly forward-looking way. In the longer run, its capacity is to be increased to up to 50 MWs. Any additional large-scale heat pumps can be added as needed.
Another innovative and particularly efficient feature are the four pipelines used in the heat network to allow for the use of industrial waste heat. There are two pipelines for district heating and two more for the backflow of waste heat. Waste heat from industry and commerce is used to heat up water that is first dispatched there before flowing back to the CHP plant. Then, large-scale heat pumps are used to further increase the temperature to the levels required for district heating. It is not so much the individual components of the system that make it innovative, but the way in which these have been interwoven to form a scalable heat network. Industry and commerce serve a dual role as users of district heating and suppliers of waste heat.
The basic principle of combining different renewable heat sources can be applied in many regions
It is particularly interesting for municipalities that are planning to build district heating networks in the vicinity of industrial and commercial sites. The basic principle of combining several renewable sources of heat, in particular, lends itself to many regions. This could make the heat network in Memmingen and its technology mix a valuable best practice example for a successful local heat transition. And, in fact, this latter is a key challenge for the energy transition overall, given that heating and cooling accounts for more than half of Germany’s final energy consumption.
Heat networks are a key component of the future heat supply. They are capable of integrating heat from different sources, e.g. river water, with heat pumps, deep and near-surface geothermal energy, biomass and also industrial waste heat. In many cases, district heating is turning out to be the key to unlocking new sustainable heat sources and to creating a future-proof heat supply, particularly for urban areas with little available land.
For this reason, the Federal Government supports the expansion and modernisation of heat networks by offering grants and bureaucracy breaks and through loans and guarantees made available through the Deutschlandfonds (Germany Fund). As it does so, it also enables the necessary private-sector investment. Through the federal funding for efficient heat networks, the Federation is providing approx. €5.9 billion in funding from the new Special Fund for Infrastructure and Climate Neutrality this year.