Tuzla plans to decarbonize its district heating system

Tuzla and EPBiH have a vision to reduce greenhouse gas emissions in the city’s heating sector to 4% of their current level by 2040 with desulphurization projects, the deployment of renewables including solar thermal technology and network expansion.

Europe’s heating sector continues to be entirely dominated by fossil fuels. According to the latest Global Renewables’ Status Report, few countries and cities are making progress in planning and supporting progressive, locally adapted solutions that work for citizens, for the economy, and for the environment. Tuzla, a city in Bosnia and Herzegovina, aspires to become a role model for the heat transition in the Balkans.

When people hear the name Salt Lake City, most think of the capital of the state of Utah in the United States and its world-famous lake. In the Balkans, people think of Tuzla, the cultural and economic heart of northeastern Bosnia. Tuzla means salt, and the city is at least 5,800 years older than its American namesake. This makes it one of Europe’s longest continuously inhabited places – and it has seen many shifts in culture and technology.

BiH’s third-largest city is burdened with a coal plant legacy of several decades

Bosnia and Herzegovina’s third-largest city with its 110,000 inhabitants has an impressive industrial heritage. Apart from the ancient salt mining which has literally sunk the city further and further into the ground, Tuzla has had a reputation for its huge coal and lignite plants that have been powering the economy and filling the skies with smoke.

Today, Tuzla stands for transition. The salt mines in the city center have been turned into Europe’s first and only urban salt lake, which draws tens of thousands of visitors every day for its medicinal properties, and which has quickly helped Tuzla’s tourism and service sectors to surpass traditional industry. However, the transformation of the energy system is an even bigger industrial challenge that the city has taken on.

New hydro, wind, PV power plants

Tuzla is the main industrial machine of BiH and one of its economic strongholds. “We started our district heating system with cogeneration units in 1983,” explains Suljo Sarić, Assistant Director for Technical Affairs at district heating company Tuzla. The combined heat and power (CHP) plant is still the biggest in the entire country.

Its capacity is 220 MW. The City of Tuzla aims to reduce greenhouse gas emissions in heating to 20,000 tons per year from the current 500,000 tons.

Lignite must be replaced by more climate-friendly alternatives

State-owned Elektroprivreda Bosne i Hercegovine (EPBiH), operator of the plants and the biggest electricity producer in Bosnia and Herzegovina, is well aware that the lignite burned at the power plant in Tuzla will have to be replaced in the not-so-distant future by more climate-friendly alternatives, if the European Union climate goals are to be met.

“For electricity production, we are working on new hydro-, wind- and PV-based power plants”, explains Ajla Merzić, Lead Expert Associate for Power Unit Development at EPBiH. “Old lignite units will be shut down by the end of 2023 at the latest, namely units 3 and 4 in Tuzla.” Unit 6 in Tuzla is being converted into a cogeneration mode, while the company works on partial replacement of coal by biofuels. Furthermore, earlier this year EPBiH finished its first wind power plant, Podveležje, which has a capacity of 48 MW, and it plans to add a photovoltaic power plant with over 30 MW at the same location.

EPBiH is developing projects for several wind and solar power plants

The company is also developing wind farm projects Vlašić in Travnik and Bitovna in Konjic of around 50 MW and 60 MW, respectively. A state-of-the-art project is to transform five former open pit coal mines and ash and slag dumps into photovoltaic power plants of 200 MW in total. All these projects are to be put into operation by 2025.

Tuzla’s heating sector could become model for Balkans

Bosnia and Herzegovina is no different than the rest of Europe as its share of renewable electricity is rapidly growing. But fossil fuels continue to dominate the heating sector in the entire continent.

Merzić explains that district heating can make a massive contribution through actions in five key areas:

1. Pollutants can be cut through desulphurization projects, by increasing the share of renewable sources in the heating sector and a decommissioning program of fossil fuel–fired units.
2. A new billing system: In Bosnia and Herzegovina, most customers still pay per surface heated and not per consumption. But ambitious emission targets require lower temperatures in the system, which will only be possible with significantly improved insulation as well as the integration of renewables such as solar heat. The government is currently drafting a law on heating.
3. Cogeneration systems need to be modernized.
4. The coal-fired CHP unit can be improved by the use of biomass and integration of solar thermal systems. Both the co-firing of biomass and complete retrofitting are being considered. But: “Not all kinds of biomass are sustainable, and so far, we are lacking regulation of the biomass chain within the country,” explains Merzić. Solar thermal could be interesting if hot water supply were included in the system. “That would be a good combination in summertime if the supply of hot tap water were included, which is not the case today. We are also investigating the use of geothermal heat and heat pumps.”
5. More buildings need to be connected to the district heating network: “People often burn anything they find, where they are not connected to the DH network,” describes Anes Kazagić, Head of the Strategic Development Department in EPBiH, highlighting how energy poverty contributes to high emissions. “But a government scheme to attract new customers in Tuzla is already in place,” he says.

Certain improvements are only possible with the integration of renewable heat-based solutions into the system. A key to this is international cooperation.

Tuzla is one of eight European cities that are pooling expertise and research in the Upgrade DH project, co-funded by the European Union. “It is very important for us to be able to exchange with the other Upgrade DH partners,” says Merzić. “We got beneficial input resulting in very concrete co-operations, for example in hydraulic questions. The relations and ties which we have developed during the Upgrade DH will continue and are of high strategic value for our plans to transition towards the new generation of climate-friendly district heating.”

Kazagić adds: “We hope that the process we have started and are undergoing now in Tuzla can serve as inspiration to other countries in the Balkans – district heating cities like Belgrade, Skopje, or Sarajevo are facing similar challenges. And we want to be a role model in the transition from fossil fuels to renewables.”

The Upgrade DH project has received funding from the European Union’s Horizon 2020 research and innovation program.