With its diverse climate varying from the coastal region with its mild Mediterranean conditions, to the mountainous continental parts with harsh winters, and everything in between, Croatia poses an interesting framework for the utilization of solutions for district heating and cooling.
District heating is currently present in 14 municipalities and covers roughly 14 per cent of the overall national heating neds. The supply comes mostly from gas (over 80%), and fuel oil (around 15 per cent ). Unlike most cases across Europe, the national utility company HEP toplinarstvo holds over 90 per cent of the market with the system in the City of Zagreb, Croatia’s capital, representing over 80 per cent of the annual district heating supply. Even though most of the district heating systems are fairly old, several positive examples can be pointed towards just in the region of North-West Croatia.
Zagreb in the lead
The building stock in Zagreb is mostly heated with individual or building scale gas fired heat only boilers, while gas fired CHP units are utilized in the district heating system, which supplies roughly 30 per cent of the city, as the main sources of supply. HEP toplinarstvo has recently secured funds through the Integrated Territorial Investments Fund for the refurbishment of a large portion of the capital’s grid . Once implemented, by the end of 2023, this action will reduce the systems overall losses by over 30 pwe cent. Together with the implementation of a large heat storage tank which has been installed recently, this will prepare the system for its inevitable transition towards the third or even fourth generation system.
Solar and Geothermal to support the energy transition
To further emphasize the transition, HEP together with the North-West Croatia Regional Energy Agency (REGEA) is exploring the possibilities to utilize large-scale solar collectors in the surrounding district heating systems located in Velika Gorica, Samobor and Zapresic as well as geothermal energy in Karlovac, Zagreb and Ivanic-Grad. Due to the proximity of the systems in Velika Gorica, Samobor and Zapresic to the one in the city of Zagreb, in addition to the high potential for the utilization of renewable sources in their supply, their connection and integration as well as a large-scale expansion of the network could have a tremendous impact. Such an action could help in the long-term decarbonisation of the entire area and support a gradual shift toward the utilization of district solutions and away from individual gas.