Geothermal Center Žiar
About the Project
After completing the geological survey in the field and the administrative preparation of the project, PW Energy presented its geothermal energy utilization project in the Žiar nad Hronom district in March 2021. The project is currently being implemented by PW geoenergy, in which SSE Holding is our strategic partner.
The planned development includes the production of electric energy and heat. The production of electric energy will take place in a binary power plant based on ORC (Organic Rankine Cycle), which will have an installed capacity of up to 8.5 MWe depending on the ratio of geothermal energy used for electricity and heat production.
The facility will utilize energy from six wells (three production and three reinjection) in a closed circuit with reinjection of thermally used geothermal water, which will ensure repeated heating of water in the subsurface and thereby long-term sustainability of the project. In the First development phase, it is planned to drill three doublets (a doublet is a production + reinjection well).
The development is planned at the geothermal center in the cadastral area of Ľubotice. Annual electricity production is anticipated to be more than 60,000 megawatt-hours in the 1st stage of the project. The total potential of the location is estimated to be three times higher. The produced heat or residual heat after the electricity production process can be utilized, for example to supply heat for district heating systems, in agriculture, industry, or for recreational purposes.
Drilling of Geothermal Wells
Electricity production will be enabled by the extraction of hot geothermal water from the deep geothermal reservoir. The wells will be located in the southern part of the Žiar Basin, as there is an anticipated occurrence of potential geothermal collectors at depths above 3,000 m.
According to measurements and data obtained, this location enables the exploitation of geothermal water at the maximum temperature achievable in the geological environment of the pre-Tertiary substrate of the Žiar Basin (140–150 °C).
A suitable drilling rig will be used for the safe and reliable drilling of the geothermal wells. The purpose of the first geothermal well GTŽ-1 (Žiar nad Hronom) with an anticipated final depth of 4,000 m is the verification of the deep geological structure and geothermal conditions in the area.
The exploration well, if geothermal water flow is confirmed, will be used as the definitive structure for long-term extraction or reinjection of geothermal water and production of green energy.
What is an Organic Rankine Cycle (ORC)?
A power plant condensation cycle that uses heated geothermal water as the heat transfer medium in the primary circuit. It transfers heat to the secondary circuit, where it heats a working fluid with a low boiling point.
The working fluid begins to evaporate at relatively low temperatures and achieves greater pressure than water, and the resulting vapors are directed to a steam turbine where they expand, causing the turbine to spin and generate electrical energy.
After the turbine the steam is directed to a condenser, where it condenses to its liquid form and subsequently re-enters the heating process via heat from the geothermal water.
The estimated annual amount of geothermal water exploited from one production well is at the level of 1,749,600 m3 (total 10,497,600 m3 from both centers annually), with all exploited geothermal water being reinjected back into the original reservoir after its thermal utilization without changes to its physico-chemical parameters, with the exception of temperature. The discharge of geothermal water into surface watercourses will not occur.
We are implementing the project in cooperation with SSE Holding.
Technical Data
8,5 MWe
≈7,5 MWe
≈60,000 MWh
Geothermal power plant with two centers with binary cycle (ORC)
480,000 tons of CO2 / 10 years
(compared to coal energy production)
280,000 tons of CO2 / 10 years
(compared to natural gas energy production)
