• Geothermal energy refers to the thermal energy stored beneath the earth’s solid surface.
• Energy from geothermal energy can be used for heating, cooling and generating electricity.

• The term “geothermal energy” is a generic term and refers to both near-surface and deep geothermal energy. The main difference lies in the depth of the borehole.
• While near-surface geothermal energy uses geothermal energy from depths of up to 400 metres, deep geothermal projects involve drilling up to several kilometres below the earth’s surface. The temperature of the thermal water rises as the depth of the boreholes increases.
• As a result, geothermal energy from deep geothermal energy can supply entire neighbourhoods with green heat or electricity, whereas heat from near-surface geothermal energy can only heat individual detached houses and apartment blocks.
• Vulcan utilises deep geothermal energy for its projects, as drilling up to 4 km underground is required to extract the lithium-rich thermal water, resulting in a greater energy yield.

Deep geothermal energy in Germany has the potential to cover over a quarter of Germany’s heating requirements (source Fraunhofer 2022).

Advantages of deep geothermal energy:

• Climate-friendly: When converting geothermal energy into electricity or heat, considerably less CO2 is produced than when generating energy from coal and other fossil fuels.
• Unlimited supply: In contrast to fossil fuels, geothermal energy is inexhaustible.
• Consistency: Geothermal energy is base-load capable and therefore available at all times. Other renewable energy sources, on the other hand, are dependent on the day or the weather. If several geothermal power plants are connected together, maintenance periods can also be bridged without any problems.
• High efficiency: Hardly any heat energy is lost when producing heat with geothermal energy.
• Low space requirement: Compared to conventional oil or gas heating systems, geothermal connection stations in households are significantly smaller. The amount of land required for installations is also significantly lower than for other renewable energies.
• Versatility: In addition to heat, geothermal energy can also be used to generate electricity and cooling.
• Service life: Geothermal systems have a long service life of at least 50 years, new systems even longer.

Disadvantages of deep geothermal energy:

• Cost intensity: The construction of a new geothermal plant is associated with high costs.
• Locally limited usability: Only a few regions in Germany have the necessary conditions for the utilisation of geothermal energy.
• High expenditure: Complex preliminary work such as deep geothermal drilling is often required to find the required temperature level in deeper layers of the earth.

• Redundancy can be achieved in several ways
  • Mobile heating power plants to bridge planned shutdowns or unplanned outages of the power plant
  • Consolidation of several locations, no downtimes during maintenance or outages of individual power plants
• The supply of heat is prioritised, but cooling and electricity are also possible. How much of what depends on the amount of district heating purchased locally and other factors.

The special thing about the Upper Rhine Graben is that it is a fracture structure.

• Rift valley, filling with sediment
• Areas outside were pushed upwards
• Differences in rock layering and depths

This has several advantages for geothermal projects:

• Simple exploitation of the target reservoir through the so-called fault zones belonging to the natural fracture structure.
• The temperatures of the thermal water between 170° and 200° enable a high heat output before lithium extraction and the conversion of heat to electricity, for example, can take place with water vapour as the working medium.
• The high underground temperatures also allow the energy to be utilised to make the extraction process CO2-neutral.
• The thermal water has a high lithium concentration of 180 mg/l.
• Possible extraction rates are particularly high due to the good rock permeability.
• A high salt content that drives the sorption process
• Comparatively low proportion of certain substances that could hinder the extraction of lithium.
• Proximity of the Upper Rhine Graben to the planned battery factories in Europe

• Seismicity describes the observable earthquake activity in a region. Seismics, on the other hand, is the technique of using seismic waves to obtain information about the subsurface.

• Seismicity is associated with any utilisation of the subsurface (e.g. mining, drinking water extraction, hydrocarbon extraction). The aim is to keep seismicity below the perception threshold and avoid even the smallest damage.
• To this end, all activities during project development and operation are monitored using highly sensitive vibration measurements and operations are adapted accordingly.
• Thanks to 3D seismic technology, we can investigate the subsurface in advance in greater detail than it was the case with previous projects. This improved knowledge makes it possible to reduce seismicity.
• Interesting to know: No deep geothermal energy was used in the incident in Staufen in which cracks occurred. These were poorly executed drilling measures for geothermal probes at a maximum drilling depth of only 140 metres (Staufen 2020: Link).

• The controlled construction and operation of a geothermal system will almost certainly prevent major damage. In the unlikely event of damage, probably of an exclusively minor nature, this will be borne by the party responsible.
• Vulcan’s concept envisages that a fund provided by Vulcan will handle small claims via an independent ombudsman.
• Insurance can come into play in the unlikely event of major or very numerous incidents. In the past, the question of current value or replacement value insurance was an issue. Liability insurance usually only covers the current value.
• In the 1970s, the German government introduced a mining damage compensation fund in which all mining companies participate on a solidarity basis. This comes into play if all other forms of cover fail for whatever reason. This cover has never been utilised since its introduction. Vulcan is also a member of the Mining Damage Compensation Fund.

• The same heat transfer media used in refrigerators and air conditioning systems are used in geothermal power generation plants. They are subject to usage and safety regulations.
• In addition, the safety precautions and fire protection regulations are very high throughout the entire plant area. The safety precautions go far beyond those of a petrol station, which stores a comparable liquid with petrol and diesel in city centres and sells it directly to the public.
• All substances that come into contact with thermal water must be authorised by the authorities and are subject to the strict provisions of water law.

• No. There are over 100 boreholes in the Southern Palatinate alone that use a recognised method. There were no cases of groundwater contamination.
• Although layers containing drinking water are drilled through, the drilling fluid seals all water-bearing layers. Several pipes are then cemented in place, which are interlocked and sealed with cement to provide multiple protection for the drinking water. The cemented gaps are also monitored for leaks using measuring devices. Measuring gauges are installed outside the drilling site in case, contrary to expectations, a change in the groundwater composition is registered.

• Lithium-rich thermal water from the underground in the Upper Rhine Graben is pumped to the surface.
• The lithium is then extracted from the thermal water using direct lithium extraction by adsorption (A-DLE). This technology has been used commercially since the 1990s .
• More precisely, the hot thermal water containing lithium is channelled through a type of filter known as a sorbent. The lithium ions remain suspended in this sorbent – the remaining thermal water flows through it.
• The heat from the thermal water is used to drive the extraction process and to provide renewable heat and electricity. Once both the energy and the lithium have been extracted from the thermal water, it is fed back into the natural reservoir – a closed cycle.

• The extracted lithium is first purified in a lithium extraction plant. It is then transported in an aqueous lithium chloride solution to a lithium electrolysis plant, where it is processed into the end product lithium hydroxide monohydrate (LHM).
• The LHM is supplied to the automotive industry via cathode and battery cell manufacturers and used for the construction of electric vehicles or for renewable energy storage (solar and wind). At the end of the battery life cycle, the lithium can be recycled.

• At the extraction plant in Landau, we obtain the lithium in the form of a highly concentrated, very pure lithium chloride solution.
• In this form, the lithium is not yet suitable for further processing in battery factories and is therefore still converted into lithium hydroxide monohydrate (LHM).
• The process used releases chlorine gas and hydrogen and therefore requires consumers in the immediate vicinity (e.g. via pipeline). The necessary technology and the consumers of the chlorine gas are located in the Höchst Industrial Park near Frankfurt.

• Vulcan’s extraction method can be described as the safest and cleanest method of extracting lithium.
• Until now, lithium has mainly been extracted in South America, Australia and China.
  • Raw materials are extracted there by brine evaporation (water containing lithium) or by mining hard rock.
  • These are CO2 -intensive processes that have a major impact on the environment and climate.
• Lithium extraction from hard rock: energy-intensive, low lithium concentrations, long transportation routes
• Lithium extraction using brine pools: high water consumption in arid regions, high CO2 footprint due to chemical processes

• VULSORB® is the in-house sorbent that Vulcan uses to extract lithium from the brine.
• The aluminate-based sorbent has a higher performance and lower water consumption during lithium extraction compared to commercially available sorbents.
• VULSORB® can be used in Europe as well as in other brines worldwide.

Learn more

• No. Lithium extraction is a physical process, which means that only a few reagents are required.
• As the entire process takes place in a closed circuit, no other substances bound in the thermal water can escape to the outside.

• Lithium itself is not harmful to the environment. It is found naturally bound in several regions of Germany. In the process used by Vulcan, the lithium is always bound in an aqueous solution, is in a closed circuit and therefore does not enter the environment.
• Risks only exist if lithium dust occurs. The only process step in which this can occur takes place at Chemiepark Höchst, where the end product lithium hydroxide monohydrate (LHM) is produced. However, we transport this promptly to the battery manufacturers.

• The Direct Lithium Extraction (DLE) by Adsorption (A-DLE) process used by Vulcan has the lowest water consumption of all lithium extraction processes. As the majority of the water used in the process is recirculated in a closed water circuit.
• Water consumption was thus reduced to a rate of 1.35 liters per kilogram of lithium hydroxide monohydrate (LHM).
  • By comparison, hard rock mining requires 15 tons of water per ton of LHM, while brine extraction requires 5 tons.

• According to our projections, we assume that lithium extraction can be operated economically for several dozen years, and heat production for at least 50 years.
• For competitive reasons, we do not want to provide any specific information on the profitability of lithium extraction.

• Commercial series production of electric cars using sodium-ion batteries as an alternative to lithium-ion batteries began at the end of 2023. Vulcan believes that sodium-ion batteries have a place in the market. Lithium-ion batteries currently have certain advantages, such as higher energy efficiency and a more mature technology base. Sodium-ion batteries, on the other hand, show advantages in terms of cost and resource availability. However, with regard to their use in e-cars, they are generally used for smaller vehicles with shorter ranges.
• With technological diversity, we can comprehensively promote innovation and sustainability. In this way, we can ensure that both technologies can coexist and contribute to a successful transition to e-mobility.

• A-DLE is a method for extracting lithium from brine (thermal water).
• The technology is already used in 10% of global lithium production – and the trend is rising.
• The advantages of A-DLE are low operating costs, reduced environmental impact, high product quality and a positive track record.

More on A-DLE

• The size of a geothermal power plant depends on various factors. The two most important are the capacity of the power plant and the form of the energy generated.
  • The capacity refers to the amount of energy that the power plant can generate. A larger power plant has a higher capacity and can therefore generate more energy.
  • The intended use refers to the type of energy generated by the power plant. Power plants that generate heat are much more compact than power plants that generate electricity.
• By the way: A special feature is that extraction sites, geothermal plants and lithium extraction plants can be connected with pipelines and therefore do not have to be built at the same location. This also makes the plant sizes more flexible.

There is no danger from a lithium extraction plant.

• Thermal water and industrial water are used, both in closed circuits.
• The process as such can be classified as non-critical, as it is merely a sorption process, a physical process.
• For the ion exchanger we need hydrochloric acid (0.3 t/h) and sodium hydroxide solution – these substances and processes are state of the art and are non-toxic, non-flammable and non-carcinogenic.

• Geothermal systems are comparatively quiet due to the process and also in comparison with other commercial systems.
• It is under constant surveillance.
• It is located in an isolated area and therefore does not cause any additional lighting at night.

• Steam is only generated when the system is started up and heats up again, e.g. after maintenance.
• In older plants, such as the plants in Landau and Insheim, steam is actually released over several hours when the plant is started up.
• This is almost pure water vapor, which poses no danger. In new plants, such as those planned by Vulcan, no steam will escape during start-up.

• The operation of a geothermal power plant can lead to induced seismicity, which is why seismic monitoring is required by the mining authorities for geothermal projects.
• The ground vibration velocities are continuously measured and evaluated at various points around the power plant.
• The aim of monitoring is to keep vibrations below the threshold of perceptibility, but in any case below the damage threshold.
• In the event of increased seismic activity, a response plan prescribed by the mining authorities comes into force. Depending on the magnitude of the measured ground vibration velocities and the frequency of occurrence, appropriate measures are initiated which can even lead to the power plant being shut down. In over 10 years of operation of the Insheim geothermal power plant, stage 2 according to the reaction matrix has not been reached.
• In addition, an independent expert draws up a monthly report on the measured ground vibration velocities. This is submitted to the supervisory authority and the State Office for Geology and Mining. In addition, measured events can be viewed on the operator’s homepage.

• The following link leads to a page on which Vulcan provides the public with access to the ground vibration velocity with measuring stations around the Insheim geothermal power plant: https://eg.dmt.de/IG/GEO_I/GEO_I.xml

• First of all, the recirculated water is not “cold”, but still has residual heat. Im Geothermiekraftwerk in Insheim sinkt die Temperatur des Thermalwassers beispielsweise von etwa 163 auf 74 Grad Celsius ab.
• Cooling can cause the rock underground to contract in the immediate vicinity of the water return borehole. However, due to the low thermal expansion coefficients of the rock, it is very low and lies below the perception threshold.
• Temperature changes in the subsurface can generally lead to stress changes and contribute to the triggering of imperceptible earthquakes. However, we can predict these effects in advance using modern numerical model calculations.