Thanks to its geographic location, Baden-Württemberg has access to a unique energy resource: thermal water in hot rock formations. Geothermal facilities can tap into this energy reservoir to generate electricity and provide heat. Deep geothermal energy has been part of our portfolio for more than 20 years, complementing wind, solar, and hydropower as another renewable energy source.
hours per year can geothermal power plants continuously generate electricity.
is the thermal capacity of the Bruchsal geothermal power plant.
meters does the thermal water in Bruchsal come from.
Bruchsal became the first geothermal power plant to begin operating in Baden-Württemberg.
The geothermal facility in Bruchsal was originally designed as a research facility. It entered commercial operation in 2009 and has reliably generated electricity ever since. Since 2019, the geothermal facility has also supplied district heating to the neighboring state police academy. Starting in fall 2026, the facility is also expected to supply its first industrial customers through an expanded district heating network.
How does deep geothermal energy work?
Deep geothermal energy harnesses natural heat from deep rock formations and thermal water reservoirs. Wells drilled to depths ranging from several hundred to several thousand meters provide access to these resources. Hot thermal water is pumped to the surface, transfers its energy through a heat exchanger, and is then reinjected into the subsurface, where it heats up again. Depending on geological conditions, the geothermal heat can be used for heating and, at sufficiently high temperatures, to generate electricity.
In 2009, we commissioned the geothermal facility in Bruchsal together with Stadtwerke Bruchsal, making it the first geothermal power plant in Baden-Württemberg. Working with strong partners, we are developing additional projects along the Upper Rhine Graben: GeoHardt, a joint venture with MVV AG, and WärmeWerk Wörth, a joint project with Daimler Truck and the City of Wörth.
Bruchsal geothermal power plant
In 2005, we launched a research and development project with Stadtwerke Bruchsal to develop deep geothermal resources at the Bruchsal site. In 2009, the facility was commissioned as Baden-Württemberg’s first geothermal power plant. It produces hot thermal water from a depth of approximately 2,500 meters and uses it to generate electricity and supply heat. Since 2019, it has also supplied heat to the state police academy. Starting in fall 2026, the facility is expected to supply its first industrial customers through an expanded district heating network.
Bruchsal is more than a geothermal energy site: lithium is also being recovered from the Upper Rhine Graben as part of a research and demonstration project.
GeoHardt
In 2021, we established the GeoHardt GmbH joint venture with MVV AG. Its goal is to secure the heat supply in the Rhine-Neckar region with baseload-capable renewable heat from thermal water. Up to three geothermal heating plants are planned in the region. Two locations have already been selected: Mannheim-Rheinau and Schwetzingen. Permitting procedures under mining law are currently underway. Site development can begin only after approval has been granted by the State Office for Geology, Raw Materials and Mining (LGRB).
WärmeWerk Wörth
Through this joint project with Daimler Truck and the City of Wörth, we aim to use locally sourced renewable deep geothermal energy to meet the Daimler Truck AG truck plant’s heating needs, both for space heating and industrial processes. There is also the potential to feed heat into the City of Wörth’s local district heating networks, helping decarbonize the region’s heat supply.
Geothermal facilities can do more than generate electricity and heat from thermal water: they can also recover lithium, a raw material used in applications such as battery manufacturing that Germany currently imports almost entirely.
Since 2017, we have been researching how to recover lithium economically from thermal water in the Upper Rhine Graben. As part of this work, we developed and patented our own lithium extraction process. Initial results from our pilot plant show a carbonate purity of 99.5%, making the recovered material potentially suitable for battery manufacturing.
We therefore plan to replace the existing research facility with a larger demonstration unit capable of producing approximately 200 metric tons of lithium carbonate annually.
EnBW milestones in geothermal energy and lithium
We have been working with deep geothermal energy for more than 20 years. What began as research has evolved into commercial operations, and we are planning additional sites. Here is how it all started:
Together with Stadtwerke Bruchsal, we launch a research and development project to tap into deep geothermal resources at the site.
Die Anlage geht in den wirtschaftlichen Betrieb und erzeugt seitdem Strom aus rund 2.500 Metern Tiefe. Sie ist das erste Geothermiekraftwerk des Landes.
We launch our first lithium recovery research project to determine how lithium can be economically extracted from thermal water in the Upper Rhine Graben.
The Bruchsal geothermal power plant begins supplying heat for the first time. A 400-meter local district heating pipeline connects the police headquarters to the geothermal plant’s heating station. The facility meets 61% of the site’s heating demand.
As part of the collaborative UnLimited project, we work with KIT and other partners to build a pilot plant. The aim is to assess the technical and economic feasibility of lithium recovery under real-world operating conditions.
Together with MVV, we establish the GeoHardt joint venture. Following the issuance of an exploration permit, preliminary geological investigations begin for potential geothermal heating plants in the Rhine-Neckar region.
Together with Daimler Truck and the City of Wörth am Rhein, we establish WärmeWerk Wörth. The joint venture investigates whether deep geothermal energy can supply heat to the truck plant and municipal district heating networks.
Our process for direct lithium extraction from thermal water is patented. Initial pilot plant results also show a particularly high lithium concentration of 160 milligrams per liter and a purity of 99.5% in the recovered lithium carbonate. This could make it suitable for battery manufacturing.
GeoHardt announces its first project site: a geothermal heating plant is planned at “Franzosenhäusel” on the southeastern edge of Mannheim-Rheinau. The next step is the permitting process under mining law.
“Rondellweg” in Schwetzingen is selected as the second planned site. The location near Plankstadt offers good access to the existing district heating network. Here, too, approval under mining law is required before the drilling site can be established.
Geothermal energy: questions and answers
Unlike solar and wind energy, geothermal energy is largely independent of weather conditions and can provide baseload heat around the clock, year-round. This makes it a reliable complement to other renewable energy sources for heating and electricity generation.
Shallow geothermal energy can be used in many locations with ground heat exchangers or groundwater wells combined with heat pumps. Deep geothermal energy is particularly economically attractive in regions with favorable geological conditions, such as high temperatures at accessible depths, and is evaluated on a site-specific basis.
Near the surface, heat comes primarily from solar radiation warming the ground. At greater depths, natural heat flow from the Earth’s interior dominates, causing temperatures to rise by an average of approximately 3°C per 100 meters of depth.
With shallow geothermal systems (down to approximately 400 meters), heat pumps typically raise geothermal heat to a usable temperature. With deep geothermal systems (at depths ranging from several hundred to several thousand meters), hot water can be used directly in district heating networks and, at high temperatures, in geothermal power plants to generate electricity.
Thermal water in the Upper Rhine Graben contains dissolved lithium ions at relatively high concentrations (approximately 160–250 mg/L at existing geothermal sites). Lithium can be recovered as a coproduct of heat and electricity generation. Closed-loop geothermal lithium recovery produces significantly fewer greenhouse gas emissions than conventional extraction from salt flats or hard-rock deposits, for example, because most of the energy required can be supplied by the geothermal facility itself. Domestic production could meet part of Europe’s demand for battery-grade lithium and reduce dependence on imports from a small number of producing countries.
A direct lithium extraction (DLE) process is being developed in Bruchsal. Specialized materials selectively bind lithium from the thermal water. The lithium is then released from the material and initially recovered as a concentrated lithium solution. This solution can subsequently be processed into high-purity lithium carbonate, for example.
The geothermal facility operates with a fully closed-loop thermal water system. Thermal water is pumped up from deep underground, used for energy generation and lithium extraction, and then reinjected into the underground reservoir. Only the lithium contained in the thermal water is removed. The water itself remains in the closed loop and is not consumed.
At the Bruchsal geothermal site, the technical potential at the current production flow rate is approximately 800 metric tons of lithium carbonate equivalent (LCE) per year. The plan is to double the production flow rate next year, potentially enabling recovery of 1,600 metric tons of lithium carbonate equivalent.