An AI system is now controlling Mertingen’s heating network

Die KI optimiert den Strombezug der Großwärmepumpe und die Wärmespeicherung – und entlastet so das Stromnetz

An AI system is now controlling Mertingen’s heating network

Buttenwiesen, 2 May 2024

A large-scale heat pump went on stream in Mertingen last November, and the heating network has kept the town supplied with renewable heat ever since. What makes this particular setup unique is the nearby solar farm, which provides a direct supply of the green electricity needed to run the system. A further milestone has now been reached with the integration of smart control powered by artificial intelligence (AI) for the heating network. This allows it to be run even more cost-effectively while relieving the burden on the power grid. GP JOULE and ProTherm Mertingen have been showcasing the new technology at a special open day for local communities.

The AI forecasts the amount of heat required and the power being produced by the solar farm next door and works out the best timetable for the heat pump and operating mode for the heating network. How much heat is being generated at the moment and fed straight into the heating network? How much of that heat is being stored? What kind of demand will need to be met in the next few hours and days? The AI is designed to answer all these questions and thus optimise energy consumption and the storage and release of heat, preventing too much – but also too little – energy from ever being held in reserve or fed into the district heating network.

The underlying technology is made up of three main components: a digital twin, which provides a virtually identical mirror-image of the real-life heating network; a machine learning algorithm, which learns from the data it receives to produce increasingly accurate forecasts; and an “optimiser”, which calculates all possible future scenarios and picks the one that will be the most cost-effective and most sustainable.

The AI system was connected up just over a week ago and has already learnt a great deal. “We’re extremely satisfied,” says Dr Matthias Stark, who developed the AI together with his team in his role as Head of Systems Engineering, Operations and Service at GP JOULE. “The forecasts are getting closer and closer to predicting what actually happens.” 

Expansion of renewables making energy storage ever more important

“With this technology, we’re really helping to take the strain off the power grid,” explains GP JOULE’s Co-Founder and CTO Heinrich Gärtner. This is because the ability of renewable sources to generate electricity is weather-dependent, with peaks on sunny and windy days, which sometimes pushes the grid to its limits. As a consequence, renewable energy systems occasionally have to be switched off. This is precisely what smart consumers like the large-scale heat pump in Mertingen are able to prevent, by consuming electricity when supply is especially high. “With the increasing expansion of renewables, therefore, it’s becoming more and more important to save energy,” Heinrich Gärtner says. In Mertingen, this is being done in the form of heat. “It’s an effective way to store large volumes of energy cheaply to be used later on,” he adds. Two large buffer storage tanks, each of which can hold 84,000 litres of water, take care of this task. 

More than 80 visitors came along to the open day for local communities to see the innovation for themselves. One reason behind the high level of interest was Germany’s new Heat Planning Act. This imposes obligations on local authorities in particular, requiring them to draw up a municipal heating plan and set out a strategy for securing a climate-neutral supply of heat in the future. “The success we’ve enjoyed in Mertingen can serve as a blueprint for that,” says Jörg Baumgärtner, who has been involved since Mertingen began planning its first heating network in his capacity as Managing Director of ProTherm Mertingen – the company operating the heating network – and finance officer on the local council.

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GP JOULE is an integrated energy supplier that covers the entire energy value chain, from generation to use – and from consulting and financing through to project planning, construction and service. GP JOULE produces and sells wind and solar power, green hydrogen and heat and makes use of it where it is most effective: in electric and hydrogen-based mobility, in households and in industry. From its base in Germany, GP JOULE has been shaping the future of energy in Europe since 2009. For a secure, independent and sustainable supply of energy. For 100% renewable energy for everyone.


GP JOULE won the 2022 German Mobility Award for its eFarm hydrogen mobility project.


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