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.
Demonstration site: Castelnuovo (Italy)
Graziella Green Power (GGP) and Storengy (STY) are developing a deep high temperature geothermal gneissic reservoir in Tuscany on the Castelnuovo Pilot lease. The project aims at exploiting a deep seated (> 3000 m) resource for power generation without rejecting into atmosphere any of the NGCs (Non-Condensable Gases). This is a demonstration project and a test case for all other projects of both industrial partners where NCGs production is an issue. Castelnuovo Pilot Project includes the drilling of 3 wells (2 production and 1 reinjection) and realizing a 5 MWe power plant. The power plant design includes an ORC (Organic Rankine Cycle) which allows to keep the geothermal fluid in a closed loop and separate the NCGs from condensed steam (liquid phase) available for reinjection. The geothermal fluid will be in a closed loop system, with 2 producers and one injector for a Zero Emission power plant. The geothermal fluid will heat up an ORC power plant of 5 MW capacity.
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.