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Castelnuovo (Italy)

Demosite Showcase

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”.


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Geology, Reservoir Properties

The demo site falls in the area of the Larderello Travale Geothermal Field where two main geothermal reservoirs exist: the “shallow reservoir” hosted in the Late Triassic evaporite and Triassic-Jurassic carbonate units of the Tuscan nappe (about 0.7 – 1.0 km b.g.l. with temperature ranging from 150 to 260 °C) and the “deep reservoir” hosted in the metamorphic units, Neogene granitoids and their thermos-metamorphic aureoles (about 2.5 – 4.0 km b.g.l. and with temperature ranging from 300 to 350 °C).

GECO Technology

The GECO technologies at the Kızıldere site include:

Reservoir modeling



History of the site

The Castelnuovo pilot concession is aimed at demonstrating the possibility of total reinjection of the geothermal fluid (brine and NCGs) in the same geothermal reservoir. According to Italian laws, these pilot plants must be limited to 5 MWe power

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10.2020 - 03.2022
Geological model of Castelnuovo-Mensano, integrated model with geophysical data (MT, GRAV-MAG, SEISMIC, CO2 flux, Geomechanical analysis) – executed
10.2020 - 03.2022
10.2020 - 03.2022
Reservoir modelling, geochemical modelling – completed
10.2020 - 03.2022
Due to delay in the authorization process the demonstration could not be executed.


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