Croatia identifies another city with geothermal potential for district heating

The testing of an exploratory well near the Croatian city of Osijek has confirmed the area’s geothermal potential, according to the Croatian Hydrocarbon Agency.

This marks the second successful completion of exploratory activities within a broader project aimed at developing geothermal potential for district heating in Croatia. At the end of June, good news came from an exploration site in Velika Gorica.

The exploratory activities in Osijek have cost an estimated EUR 8 million, with the funding secured from the National Recovery and Resilience Plan (NRRP).

Testing and measurements of the Osijek GT-1 (OsGT-1) well revealed a reservoir temperature exceeding 100 degrees Celsius, with an estimated thermal capacity of nearly 5 MW.

Temperatures are lower than in Velika Gorica

These results confirm that Osijek possesses significant geothermal resources with potential applications in district heating, agriculture, and the area’s economic development, according to the Croatian Hydrocarbon Agency.

“Geothermal energy is one of the most stable renewable energy sources, and our research confirmed the substantial potential of reservoirs in the Pannonian Basin and a strategic opportunity for achieving long-term supply security and decarbonization of the energy system,” stressed Marijan Krpan, president of the agency’s management board.

Exploratory activities continue in other locations

Due to local geological specifics and the shallower depth of the reservoir, temperatures in Osijek are lower than those in Velika Gorica. The agency noted that although the geological conditions and reservoir depths differ between Velika Gorica and Osijek, geothermal energy is flexible enough to be adapted to local needs and used efficiently and sustainably.

According to Osijek’s mayor, Ivan Radić, geothermal energy is becoming a locally available and sustainable heating source not only for Osijek residents but also for businesses.

Following Osijek and Velika Gorica, exploratory activities will continue in Vinkovci, and later in Zaprešić. After completing all exploratory activities, additional wells are planned at sites with confirmed geothermal potential.

In addition to the state-funded activities, private companies such as ENNA Geo are also engaged in geothermal research.