The stated goal is to move away from fossil fuels as much as possible and toward 100 percent renewable energy. To achieve this, GP JOULE from Reußenköge in Schleswig-Holstein is dedicated to pioneering projects such as the industrial-scale air-source heat pump currently being built in Mertingen (Donau-Ries district). It draws its electricity directly from a photovoltaic park and thus supplies climate-neutral heat for the heating network. This is a unique project on this scale.

In line with the heat transition

Since 2016, households, businesses and municipal buildings in the Bavarian municipality of Mertingen have been supplied with sustainable heat from the local heating network of ProTherm Mertingen, a company owned almost equally by the municipality of Mertingen and GP JOULE. Up to now, the heat has been provided primarily from biogas waste heat from two local production companies. Due to the expansion of the network and the associated increase in heat demand, another generation plant is now being added. For this purpose, an air-source heat pump system, fed by green photovoltaic energy, will be integrated into the local heating network as a heat generator. In addition, the heat pump draws grid electricity when it is available in surplus. "Our goal is efficient and CO2-free heat generation," explains Felix Schwahn, managing director of GP JOULE WÄRME.

Advantages wherever you look

The integration of a directly connected ground-mounted photovoltaic system to supply power to the heat pump system enables the use of renewable energy at the point of generation and provides a comprehensive win-win-win situation, because, according to those responsible, it is good for the energy system, as the electricity does not burden the grid, good for the region, as the added value remains local - and good for the climate.

"Blueprint for many more local heating networks"

"The commissioning of the first air-source heat pump supplied with green electricity on this scale for a municipal local heating network in the fall of 2023 is a lighthouse project with a blueprint effect for many other local heating networks that GP JOULE is currently developing. Based on practical experience, we can demonstrate the possibilities that arise when you intelligently connect the sectors on site," says Felix Schwahn and continues: "In October, the two-stage heat pump with 700 kilowatts of thermal output is scheduled to go into operation. It can provide flow temperatures of up to 80 degrees Celsius. The expansion of the heating network is running in parallel. In addition to the existing photovoltaic system with 750 kilowatts peak, another three photovoltaic systems with approximately 30 megawatts peak are under development in Mertingen. The majority of the electricity is to be consumed locally - to provide heat as well as to supply electricity to companies."

Artificial intelligence also makes its contribution

In addition, there are two buffer storage tanks, each with 84,000 liters of water capacity, which in the future will hold the thermal energy generated by the heat pump, which can then be distributed to the local heating network and the connected households as needed. Optimized control of the heat pump for safe and favorable operation in the energy system is provided by a digital twin, which uses AI to forecast heat requirements in the network, the electricity market situation and the availability of other heat sources.

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