SCIENTIFIC PAPERS

District heating systems are a cornerstone of urban energy infrastructure, providing a reliable and efficient method for heating residential, commercial, and industrial areas. District heating involves distributing heat generated at a central location to meet the heating needs of residential and commercial buildings. District heating systems offer a highly sustainable solution for supplying heat to cities, as they efficiently distribute heat generated from various energy sources, including renewables. By centralizing heat production and reducing energy waste, district heating minimizes emissions and enhances energy efficiency. This approach plays an important role in achieving sustainable urban energy management.

The uniqueness of district heating lies in its ability to progressively shift towards renewable energy sources, transforming it into a green superstar. By integrating renewables into its heat supply, district heating can significantly reduce carbon emissions and support sustainable urban development. This evolution positions district heating as a key player in the transition to greener energy solutions. In Leipzig, the city-owned utility company, Leipziger Stadtwerke (LSW), has integrated AI and IoT technologies into their district heating system to enhance efficiency and sustainability. The AI-driven system uses data from thousands of sensors across heating stations, power plants, and other connected devices to predict heat demand accurately. This predictive capability allows LSW to optimize the scheduling of heat production assets, ensuring that the right amount of heat is generated at the right time. Additionally, the use of a digital twin—a virtual model of the city’s energy infrastructure—enables real-time visualization and control of energy flow, improving decision-making and the overall efficiency of the heating network. This AI-based approach helps in integrating renewable and alternative heat sources, making the system more adaptable and sustainable. These innovations are part of broader efforts, such as the EU project SPARCS, which aims to create sustainable, low-carbon communities by linking and optimizing energy systems at various levels, from neighborhoods to entire cities.

In the context of climate change mitigation, calls for methods that can facilitate co-creative practices and processes between different stakeholders in the development of sustainable and climate-neutral urban districts have been increasingly expressed in recent years. This has included calls for collaborative, accessible, transparent and open tools that can facilitate urban development processes and engage different stakeholders in the different phases and stages of an urban district development process towards shared targets on sustainability and emission reduction.

In this paper, we present and examine two practical tools, 1) a co-creation model for developing positive energy district (PED) solutions, and 2) a digital twin tool for shared data sharing and collaboration, which were developed and utilized recently in two development projects focusing on Kera district, Espoo, Finland. The Kera district is a current brownfield area, which, since the early 2020s, has been undergoing a transformation from a former industrial and mass logistics area into a future mixed-use urban district with significant emphasis on sustainability and circular economy targets. We utilize actor-network theory (ANT) to explore the human and the non-human actors and their interrelations related to the district’s development. Additionally, we seek to understand the networks that emerge within both the co-creation process and the virtual urban digital twin environment and the role these tools have in supporting the formation and facilitation of multi-stakeholder co-creation networks. Finally, we aim to examine the advantages and disadvantages of integrating a regional urban digital twin and the urban co-creation process to enhance sustainability in urban development projects.

This paper presents the Positive Energy District Database (PED DB), a pivotal web tool developed collaboratively by the COST Action ‘PED-EU-NET’, in alignment with international initiatives such as JPI Urban Europe and IEA EBC Annex 83. The PED DB represents a crucial step towards sharing knowledge, promoting collaboration, reinforcing decision-making, and advancing the understanding of Positive Energy Districts (PEDs) in the pursuit of sustainable urban environments. The PED DB aims to comprehensively map and disseminate information on PEDs across Europe, serving as a dynamic resource for sustainable urban development according to the objective of making the EU climate-neutral by 2050. Indeed, PEDs imply an integrated approach for designing urban areas—the districts—where a cluster of interconnected buildings and energy communities produce net zero greenhouse gas emissions, managing an annual local/regional overflow production of renewable energy. The paper describes the collaborative step-by-step process leading to the PED DB implementation, the current results and potentials of the online platform, and introduces its future developments towards a more user-friendly and stakeholders-tailored tool.

This study assesses customer behavior under flexible electricity tariffs and evaluates demand-side management, paired with a Virtual Power Plant (VPP), for creating positive energy districts (PEDs). The research explores technical, economic, and environmental aspects of residential demand response. A techno-economic energy system model optimizes customer cost and utility margin, projecting scenarios for short and long-term developments. The model accounts for increasing customer numbers and load-shifting potential across distinct customer groups. Results indicate that acceptance scenarios unlock higher load-shifting potential, especially with VPP-based tariffs tied to renewable energy sources. This encourages load shifting, improving the local energy system’s hourly imbalances. Economically, using customer flexibility leads to welfare gains, particularly for residential customers. However, cost savings vary among tariffs and customer groups, with dynamic VPP tariffs showing the most significant savings. The study suggests increasing price volatility or changing taxation systems to cover smart metering costs. While utilities may see reduced margins with dynamic tariffs, they gain in enhancing local energy autonomy. Residential demand response proves valuable in replacing conventional power plants for residual load provision, but further economic benefits and balancing group management require additional research.

The energy industry, including Leipziger Stadtwerke, explores blockchain’s potential within the SPARCS program to boost renewable energy use and cut emissions, but caution is warranted due to high risks and regulatory hurdles. Blockchain, a secure, distributed database, enables tamper-proof transactions through encrypted blocks and smart contracts, yet its implementation faces challenges in technical infrastructure readiness and regulatory complexities. While blockchain offers transformative potential, especially in peer-to-peer energy trading and reshaping energy company roles, significant upgrades and market acceptance remain key barriers, suggesting a need for cautious testing within smart city initiatives to assess feasibility and maturity in the energy sector.

Due to the efforts for climate neutrality and the change towards electric mobility, several new business models and players have established themselves in the field of “electric mobility” in recent years. The operation of charging infrastructure and charging station management and billing systems has become a lucrative business field and many different players have focused on this area and driven innovation in this sector. For example, the operation of charging infrastructure and the billing of charging processes are now part of the extended business field of many municipal utilities. The activities of the companies in the e-mobility ecosystem and the services to the customers currently mainly comprise the provision of charging energy and the billing of charging processes. Other services to customers and the integration of payment processes into other processes currently play only a minor role, but could increase the user experience and customer satisfaction in the future. The extent to which an integration of further services is possible and what corresponding services as well as business models could look like was analysed within action L16-2 of the SPARCS project. According to the proposal, the focus therefore was set on the reservation of charging spaces, the selection of charging tariffs and priority setting. The results of the examinations are presented in the following. This document is relevant for stakeholders who would like to develop or implement services in the context of “charging” (e.g. flexible tariffs) in the future and would like to receive an overview of the corresponding framework conditions and challenges.

Positive Energy Districts (PEDs) constitute an emerging energy transition paradigm, with an ambitious timeline for rapid upscaling to match the urgency of climate mitigation and adaptation. Increasingly networked and coordinated actors aim to realise 100 PEDs across Europe by 2025. This resonates with the mission orientation turn of the European Green New Deal, to inspire and enable target-driven innovation. Yet it raises questions that have long perplexed scholars and practitioners in energy transitions: how can rapid diffusion be achieved in a sustained and replicable manner in diverse socio-technical contexts?

This paper looks at the five cities of Maia, Reykjavik, Kifissia, Kladno and Lviv that are a part of an ongoing H2020 project. The purpose of the paper was to understand the status quo of energy transition in these five cities as they embarked on the PEDs journey and identify associated challenges and benefits that PEDs brought to each city. The information was collected through a knowledge gap survey, City Vision 2050 workshop, discussions during the City Forum and individual interviews with city representatives. Cities across Europe and beyond may find themselves in a similar situation, and therefore, this paper also provides brief set of checkpoints to prepare new cities for the PED journey, thus enabling them to transition towards PEDs more efficiently.

This paper proposes a seven-step methodology for assessing the impact of smart city interventions and presents a use case for the city of Espoo. A number of major findings were the outcome of our research and development work, such as the need for a thorough analysis of the long-term vision of the city, a combined top-down and bottom-up approach and the ongoing cooperation between all stakeholders involved in urban planning and transformation, in which necessary Key Performance Indicators (KPIs) are defined.

District heating is a major energy infrastructure in many urban settlements in the world, contributing significantly to greenhouse gas emissions. Decarbonising district heating is an important step towards the realisation of a carbon-neutral society that entails considerable socio-technical change. Building on sustainability transitions literature that has dealt with socio-technical reconfiguration, this paper investigates the barriers to the implementation of a low-carbon district heating system that is based on biomass incineration minimisation and the total phasing out of fossil fuels.

This paper looks at citizen engagement in Espoo (Finland) and Leipzig (Germany), and it determines whether the cities are ready for developing and implementing positive energy districts (PEDs). The authors studied the cities’ operations and current citizen engagement methods to understand how the efforts could be combined and improved.