Geothermal energy is the energy kind of the future. The advantages are obvious: regenerative and base loadable; independent of climatic fluctuations, seasons and daytime; geothermal energy warrants a continuous power supply. Essential for a successful long-term operation is a well explored reservoir as well as the protection of the reservoir. This requires not only the determination of the basic parameters - pumping rate and temperature - but also the detailed characterisation of the geothermal water.
A long-term utilisation of a geothermal power plant demands an understanding of the thermal water system and a characterisation of the reservoir.
Thermal water assessment:
- hydrochemical composition
- determination of the origin
- recharge conditions
- age composition
- water flow regime
Characterisation of the reservoir:
- reservoir size and usability
- possible changes of the system
- interactive impact
- prevention of breakdown
The hydrochemical analysis of water based on the composition of positive and negative ions is used to assess the reservoir characteristic and the interactions between water and rocks.
Gasphysical analyses of carbondioxid, hydrogen sulphide, nitrogen, methane etc. provide a fingerprint of the individual geothermal systems.
By means of isotope hydrological analyses of the oxygen-18 and deuterium contents a characterisation of the formation conditions is possible. Also climatic information, age determination, and water-rock-gas-interactions can be derived from isotope methods.
The groundwater chemism as an origin-specific fingerprint it essential for the exploitation of a geothermal system.