Demonstration site: Hellisheidi and Nesjavellir (Iceland)
Hellisheidi and Nesjavellir power plants are located on the southern and western parts of the Hengill volcanic system. Both are co-generative, flash-unit power plants producing both electricity and hot water from a high temperature basaltic reservoir. Nesjavellir and Hellisheidi were commissioned in 1990 and 2006. Since 2007, OR has been developing new solutions in reducing gas emissions at Hellisheidi through the CarbFix project. Pilot scale capture and injection commenced in 2011 and industrial scale capture has been built up in stages since 2014. Capture of CO2 and H2S is carried out via a scrubbing unit that only uses water and electricity. Captured gases are injected dissolved in water back into the geothermal reservoir where monitoring has demonstrated their fate to be rapid mineralisation. Currently about 1/3rd of CO2 and 2/3rd of H2S are captured in this process at Hellisheidi. No capture and injection is taking place at Nesjavellir yet. GECO aims to improve efficiency of pre-existing gas capture and injection infrastructure at Hellisheidi, turn captured CO2 into value stream at Hellisheidi, and commence pilot scale capture and injection at Nesjavellir.
[substituting Castelnuovo (Italy)]
[substituting Castelnuovo (Italy)]
Storengy (STY) is developing a test unit to demonstrate the feasibility of the total geothermal fluid reinjection (including NCG’s) in a single well in high temperature (>150°C) steam dominated reservoir. The demonstration in a high temperature gneissic reservoir initially planned in Castelnuovo in Tuscany (Italy) is going to take place in Hveragerði (Iceland) due to permitting issues. The Castelnuovo site’s characterization and modeling are nevertheless part of the GECO project.
Storengy (STY) is collaborating with the Iceland GeoSurvey (ISOR) to develop the closed-loop test unit and demonstrate it in a 200°C well in Hveragerði, Iceland. To simulate similar reservoir conditions as in Castelnuovo, the geothermal fluid will be supplied with a CO2 tank and steam.
This testing operation will allow for the first ever geothermal system utilised for production/injection flow tests at nearly “zero aeriform emission”.
Demonstration site: Kızıldere (Turkey)
The Kızıldere geothermal field is Turkey’s first and high-potential geothermal field explored for energy generation. It is a high temperature metamorphic reservoir situated in the Denizli Province, southwestern Turkey. It is a complex of 3 power plants, Kızıldere-I, -II and -III. Zorlu Energy got the concession rights of Kızıldere field in 2008. Kızıldere-I is the first Geothermal Power Plant (GPP) of Turkey commissioned in 1984 with 15 MWe capacity and still operating. By taking into account reservoir feasibility studies, Zorlu constructed and commissioned its second plant Kızıldere-II with 80 MWe capacity in August 2013. The 165 MWe Kızıldere-III GPP is completely operational since March 2018. Nearly 1/3rd of the discharged NCG from Kızıldere-II is sent to a CO2 facility named Linde Gas. Linde Gas processes the CO2 for commercial activities. Through the GECO project, Zorlu Energy aims to reduce the CO2 emissions for more green geothermal power production while maintaining the sustainability of the reservoir.
Demonstration site: Bochum MULE (Germany)
The Ruhr Metropolitain Underground Laboratories (MULE) at Bochum is a large-scale facility for technology development for the changes of energy systems in urban areas. MULE has a 50 km2 geothermal mining permission with a test site right in the center of one of the largest European urban areas. The test plant shall study the effects of the injection of hydrothermal fluids enriched with CO2 into a low temperature sedimentary reservoir. It will consist of a dual flow and injection system (400 l/Min) with a closed flow-loop reactor and two 500 m wells. Emissions are controlled by an array of monitoring wells for induced chemical, hydraulic, thermal/fibre optic, seismic effects. Using MULE as GECO demo site, the Bochum Geothermal Centre is aiming at studying the effect of CO2 injection on the sandstone formation for further injection experiments.