Heidelberg relies on green heat: climate-neutral future from 2025!

Heidelberg relies on green heat: climate-neutral future from 2025!

The city of Heidelberg has been working intensively for several years to achieve climate neutrality. A central measure is the conversion of the heat supply to green district heating, which has been pushed forward since 2011. A significant innovation in July 2023 was the commissioning of the innovative iCHP system in the Pfaffengrund Energy Park, which shines with its technical equipment and flexibility. This plant combines several technologies, including three combined heat and power plants (CHP) with an electrical output of 6,000 kW, which produce 21,000 MWh of heat and the same amount of electricity annually. In addition, three air-water heat pumps with a total output of 4,500 kW and a heat production of 7,800 MWh are used, as well as a power-to-heat system with an output of over 1,800 kW electro.net reported.

But how does it all work exactly? The heat pumps extract heat from the surrounding air and transfer it to water. Each pump is capable of moving around 500,000 m³ of air per hour. To maximize the efficiency of the heat pumps, 22 low-harmonic frequency converters from ABB are used. These reduce harmonics to less than 3% and enable flexible adaptation to fluctuations in the power grid. This technical finesse not only increases energy efficiency - the system technology is a step towards Heidelberg's green future.

The path to CO2 neutrality

A remarkable step on the way to CO2 neutrality in district heating supply in Germany is the “FernWP” research project. This examines the use of large heat pumps that could use natural and industrial heat sources. District heating should be CO2-neutral by 2045, in line with national climate protection goals. The current district heating supply, which is largely based on industrial waste heat and depends on coal-fired power plants, will be converted to sustainable technologies. According to a report by Ingenieur.de This project is led by the Fraunhofer Institute for Energy Infrastructures and Geotechnologies IEG and considers both technical and economic challenges in the use of large heat pumps.

Of course, the focus is not just on the technical aspects. The project also includes an analysis of eight power plant locations to examine their suitability for the installation of large-scale heat pumps. The availability of natural resources such as air, water, geothermal energy and the optimal temperature levels are crucial. There are also numerous low-temperature heat sources in Germany that could be used efficiently through the use of large heat pumps.

Challenges and opportunities

The impending phase-out of coal by 2038 at the latest represents a challenge for district heating supply. In order to overcome this challenge, coal-fired power plants must be replaced by sustainable technologies. Large heat pumps could make a significant contribution to decarbonization here. Converting existing coal-fired power plant sites to these modern technologies is a realistic possibility, even if this involves significant investments and adjustments. In addition to increasing efficiency through lower network flow temperatures, this opens up new perspectives for sustainable heat supply.

Heidelberg impressively shows how innovative approaches and technologies in heat supply can ensure greater climate protection. Given the ambitious climate goals, the development in the city is an important signal for other regions in Germany and beyond.