April 21, 2024


A Croatian energy company has discovered an underwater lake of superheated water that could supply the country’s far north with clean geothermal electricity.

The find was the result of a two-year study by state-run power company Bukotermal that sought to find suitable sites for the exploitation of the energy source, generated by heat from the Earth’s core.  

The research verified the presence of a geothermal water source at Lunjkovec – Kutnjak field, located in the Varazdin County, close to the border with Hungary. The underground lake, located at a depth of 2.4 kilometres, has an average temperature of 142.03 degrees Celsius.

Varazdin County confirmed on Tuesday that the site meets all the requirements for the construction of a 16MW geothermal power plant. That’s enough energy to supply tens of thousands of homes.

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To date, over 2.5mn has been invested in the project. However, according to Alen Pozgaj, CEO of Bukotermal, the total cost to build the plant would be around 50mn. 

The news comes just days after the Croatian Ministry of Economy and Sustainable Development awarded five licences for the exploration of geothermal waters to firms from Croatia, the United Kingdom, and Turkey. 

The tender was issued by the Croatian Hydrocarbon Agency, has a value of over €40mn, and concerns five areas in the region’s north and northeast that already have existing wells, a legacy from retired oil and gas operations. Tapping these wells means companies don’t have to drill new ones, cutting the risk and costs for investors, said the Ministry.

Croatia has been ramping up efforts to exploit its extensive geothermal resources in recent years as it looks to wean itself off imported fossil fuels. The Balkan state, as well as its neighbours Hungary and Slovenia, sits on a geologically active area known as the Pannonian region. In this area, the water is boiling a little more than a mile down and gets hotter the deeper a well is drilled.

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

In the EU, Italy is by far the largest electricity producer from geothermal energy with some 915MW capacity, followed by Germany (38MW) and Portugal (30MW). While Croatia’s installed capacity is much lower, but the government has committed hot water pools have the potential to supply one-third of the country with clean electricity if harnessed.  

There are already projects underway in the country that pump hot water from under the ground to heat entire towns, and farmers are using the technology to warm their greenhouses. The country’s first geothermal power plant was put into operation in 2019. 

The Velika Ciglena power plant has 10MW of installed capacity, which corresponds to the average consumption of 29,000 Croatian households. That’s equivalent to about the electricity generated by about 94 football fields of solar panels, on a plot of land that is less than a tenth that size.