Sustainable transformation of district heating networks: a case study of Salininkai

Global climate challenges, driven by rising greenhouse gas emissions and unsustainable energy practices, demand urgent action to transition toward cleaner and more efficient energy systems. The European Union has set ambitious targets to combat climate change, promoting renewable energy adoption and efficiency. Lithuania plays a crucial role in this transition with its cold winters and reliance on centralised heating systems. District Heating Networks (DHNs), which supply heat to residential and commercial buildings, are vital to achieving energy efficiency and sustainability in Lithuania’s urban areas. The Salininkai DHN in Vilnius serves 46 buildings, including residential structures, a kindergarten, a supermarket, and small businesses. Powered by two 4.7 MW gas boilers with 85% efficiency, the system faces substantial heat losses due to its centralised heating point at one network corner and inefficiencies in many buildings with F and G energy class ratings and outdated radiator systems. This study evaluates Salininkai’s energy production and distribution systems to improve efficiency and sustainability. Using EnergyPRO, the analysis simulates various scenarios, including integrating a 1 MW electric air-to-water heat pump, a 3,000 m³ thermal storage system, and a solar park to reduce natural gas and commercial electricity dependency. Additionally, it explores repositioning the heating source to the network’s centre and decentralising the network. The insights gained will guide recommendations to optimise heat distribution, reduce energy losses, and enhance the network’s sustainability, which will be vetted by the Primary Energy Factor (PEF). These strategies could position the Salininkai DHN as a model for similar networks facing comparable challenges worldwide.