| Title | Integration of CO2 storage in deep geothermal energy: technical potential and industrial policy perspectives through climate protection contracts in Germany |
|---|---|
| Authors | C. Trost, B. Richter, F. Eichinger |
| Year | 2026 |
| Conference | World Geothermal Congress |
| Keywords | |
| Abstract | The integration of CO₂ storage into deep geothermal systems presents an innovative approach to simultaneously deliver renewable energy and reduce industrial emissions. This study evaluates the technical feasibility of injecting CO₂ into geothermal reservoirs, using a cement industry case study, and explores its alignment with Carbon Contracts for Difference (CCfDs). Central to this concept is the CO₂-DISSOLVED approach, where CO₂ is fully dissolved in geothermal brine prior to injection. This enables secure, mineralizing storage without a free gas phase, while concurrently harnessing geothermal energy. Modelling indicates that with a flow rate of 100 l/s and full CO₂ dissolution, up to 65,000 tonnes of CO₂ can be stored annually under stable reservoir pressure conditions. Simultaneous heat and power generation (e.g., via ORC systems) is feasible. Key technical challenges include geochemical reactions (e.g., pore structure changes, carbonate precipitation), pressure management, and induced seismicity. Robust monitoring strategies—such as 4D seismic imaging, geochemical water analysis, and numerical reservoir simulations—are essential. CCfDs offer financial incentives by bridging the gap between CO₂ abatement costs and market prices, enhancing the economic viability of such projects. This technology is particularly relevant for hard-to-abate sectors (cement, steel, glass, paper) located near geologically suitable regions. The case study demonstrates that CO₂ storage and geothermal energy production can be technically and economically viable, delivering a dual climate benefit. |