Low2HighDH Roadshow visits Karmelava to support the transition towards sustainable district heating

The Low2HighDH project continues its Roadshow series across the 10 pilot district heating sites, bringing together district heating operators, municipalities and local stakeholders to discuss practical pathways towards cleaner and more efficient heat supply.

In March 2026, the Low2HighDH team visited Karmelava, Lithuania, where the district heating system is operated by UAB Komunalinių paslaugų centras.

The visit provided an opportunity to gain first-hand insight into the local district heating system and the community it serves. In addition to touring the district heating plant, the project team visited residential buildings and a local school supplied by the network, helping to better understand the role of district heating in supporting everyday life for local residents and public institutions.

A key part of the visit was the Roadshow meeting, which brought together representatives of the municipality, housing associations, the district heating operator and other local stakeholders. During the session, the Low2HighDH experts presented the site’s tailored Technical and Investment Plans, outlining the proposed improvements to the district heating system and the investments needed to support its long-term decarbonisation.

These discussions play an important role in the Low2HighDH approach. By engaging all relevant local actors from the early planning stages, the project helps build a shared understanding of the proposed solutions, encourages collaboration and creates the support needed for future implementation.

The Karmelava district heating system is a centralised high-temperature network that currently uses lumpy peat as its primary fuel. Through Low2HighDH, the operator is receiving dedicated technical and economic support to identify the most suitable pathway towards a cleaner and more sustainable heat supply.

The proposed transition has the potential to deliver significant environmental benefits, including:

– Around 1,980 tonnes of CO₂ emissions avoided each year
– More than 3,300 MWh of fossil fuel use replaced annually
– A future district heating mix based on 100% renewable heat

The Karmelava Roadshow demonstrated that successful district heating decarbonisation depends not only on technical solutions, but also on strong cooperation between local authorities, district heating operators, housing associations and the wider community.

As Low2HighDH continues its Roadshow series across all 10 pilot sites, these meetings are helping transform technical and investment plans into a shared vision for the future—laying the foundations for cleaner, more resilient and more sustainable district heating systems across Central and Eastern Europe.

Transforming Urban District Heating Towards a Cleaner and More Resilient Future

How can a large urban district transform an existing high-temperature district heating system while maintaining reliable heat supply for its community? In Petržalka, one of Bratislava’s largest residential districts, the answer lies in a gradual transition towards a more diversified, efficient and renewable heat system.

As part of the Low2HighDH project, Petržalka is one of 10 pilot district heating sites across Lithuania, Poland and Slovakia receiving support to develop tailored Technical and Investment Plans. These plans identify practical pathways to reduce fossil fuel dependence, increase the use of renewable and low-grade heat sources, and prepare the investments required for the future of district heating.

Petržalka’s district heating system
The district heating system operated by Veolia Slovensko is a centralised high-temperature network currently based on natural gas. Through Low2HighDH, the site is receiving dedicated technical and economic support to assess decarbonisation opportunities and define a pathway towards a more sustainable heat supply.
The scale of the transformation is significant. According to publicly available information from the Municipality of Petržalka, Veolia’s wider Nová Petržalka modernisation project foresees the installation of heat pumps across local boiler houses, including air-to-water and water-to-water systems, alongside modernised cogeneration units.
The objective is to diversify heat production, improve system efficiency and reduce dependence on natural gas while ensuring that residents continue to receive reliable heating services.

Potential impact of the transition
Within the Low2HighDH pilot, the proposed transition pathway for Petržalka could contribute to:

– Around 1,494 tonnes of CO₂ emissions avoided every year
– More than 6,700 MWh of fossil fuel use replaced annually
– Around 73% renewable contribution to the future heat mix

These figures highlight the potential of transforming existing district heating infrastructure rather than replacing it entirely. The transition towards cleaner heating requires a step-by-step approach that combines the diversification of heat sources, integration of new technologies and careful planning of future investments.

Connecting technical solutions with local needs
The transition towards cleaner district heating is not only a technological challenge — it also requires collaboration among the stakeholders who operate, manage and rely on these systems.

Following the development of the technical assessments and investment pathways, the Low2HighDH Roadshows, organised in June, brought together district heating operators, municipalities, housing representatives and other local stakeholders. The discussions focused on the proposed solutions and helped connect technical plans with the practical needs of communities and institutions.

For Petržalka, this means looking beyond the heating plant itself and considering how the future district heating system can provide cleaner heat, strengthen energy resilience and continue delivering reliable services to a large urban population.

A pathway towards sustainable district heating
Petržalka demonstrates the scale and complexity of the transformation required across Europe’s district heating sector. Moving from a high-temperature, gas-based system towards a more diversified and renewable heat supply requires long-term planning, investment and cooperation between technology providers, operators, municipalities and communities.

Through Low2HighDH, Petržalka is exploring a pathway that combines cleaner technologies with practical investment planning — supporting the transition towards more sustainable, efficient and resilient district heating systems.