In a groundbreaking revelation, a Croatian energy company has uncovered an underwater reservoir of superheated water, holding the potential to supply clean geothermal electricity to the northern regions of the country. This extraordinary discovery is the culmination of a two-year investigative effort undertaken by the state-owned power company, Bukotermal, aimed at identifying suitable locations for tapping into the Earth’s core-generated energy.

The extensive study has validated the presence of a geothermal water source in the Lunjkovec – Kutnjak field, nestled within Varazdin County, close to the Hungarian border. Located at a depth of 2.4 kilometers, this subterranean reservoir maintains an average temperature of 142.03 degrees Celsius.

Varazdin County recently confirmed that the site meets all the prerequisites for the construction of a 16MW geothermal power plant, with the capacity to supply power to tens of thousands of homes. The project has thus far attracted investments exceeding €2.5 million. However, according to Alen Pozgaj, CEO of Bukotermal, the estimated total cost for establishing the plant stands at approximately €50 million.

This significant revelation follows closely on the heels of the Croatian Ministry of Economy and Sustainable Development awarding five exploration licenses for geothermal waters to companies from Croatia, the United Kingdom, and Turkey. This tender, facilitated by the Croatian Hydrocarbon Agency, carries a substantial value of over €40 million and applies to five regions in the northern and northeastern parts of the country. These regions already possess existing wells, a legacy from retired oil and gas operations, which significantly lowers drilling costs and reduces risks for potential investors, as affirmed by the Ministry.

In recent years, Croatia has been intensifying its endeavors to leverage its abundant geothermal resources as part of a broader strategy to reduce its dependence on imported fossil fuels. Situated in the geologically active Pannonian region, Croatia, along with its neighboring Hungary and Slovenia, benefits from increasingly higher water temperatures at greater well depths.

Marijan Krpan, the head of the Croatian Hydrocarbon Agency’s managing board, emphasized, “Based on an extensive database, we know that the Pannonian area has perfect conditions for the development of the geothermal business, with a geothermal gradient 60% higher than the European average.”

Although Croatia’s installed geothermal capacity falls behind European leaders like Italy, the government remains confident in the potential of its geothermal resources, particularly the hot water pools, to provide a substantial portion of the country with clean electricity, given effective utilization.

Croatia has already initiated multiple projects that utilize hot water extracted from subterranean sources to heat entire communities, and agriculturalists are employing this technology to warm greenhouses. The country’s maiden geothermal power plant, the Velika Ciglena power plant, initiated operations in 2019, boasting 10MW of installed capacity, equivalent to the average consumption of 29,000 Croatian households.

For proponents of geothermal energy, it represents a reliable source of 24/7 power, less susceptible to weather-related fluctuations than wind and solar power. Moreover, it is less vulnerable to extreme weather conditions, a common challenge for hydropower dams during droughts.

Nevertheless, geothermal energy’s potential fluctuates from one site to another, and drilling wells can entail significant costs. There’s often uncertainty regarding the water quality from a drill hole, which can deter potential investors. Croatia’s approach of repurposing existing wells from prior oil and gas exploration is a practical solution to cost constraints and challenges.

Bukotermal now has a six-month timeframe to outline its strategy for harnessing the newly discovered geothermal reservoir. The company envisions the construction of one or more geothermal power plants and heat utilization facilities at the site, with construction expected to commence within the next two years.

By Impact Lab