In this paper, a methodology for calculating the energy balance at the district level and energy performance of those districts aspiring to become a Positive Energy District (PED) is proposed. PEDs are understood as districts that achieve a positive energy balance on an annual basis by means of exporting more energy than is consumed within their limits. The main issue to standardize the concept, besides which characteristics should be considered, is that current standards to calculate an energy balance are not applied at the district level. This paper reviews the current standards and adapts them to propose an energy balance calculation methodology. Calculation of an energy balance at the district level is complex since it includes several parameters, such as which loads (or elements) should be included, which renewable energy technologies should be considered on-site production, and which primary energy factors should be used. The proposed methodology is thought to help cities at the design stage of a district and to evaluate its annual energy balance. The methodology is performed in eight steps, and all the needed assumptions that affect the calculation of the annual energy balance are discussed in each step.

Districts can be considered as a system of complex interconnections, interactions, relationships and flows. Therefore, a comprehensive approach is essential for effective decision-making with regards to energy efficiency improvement. When addressing interventions with a wider scale, the range of possible interventions is greater, as well as the possibilities of new business models to make bankable the interventions. However certain barriers can appear linked to the interactions among stakeholders, which are usually more complex than when tackling individual actuations. To overcome these barriers it is necessary to establish integrated and systemic methodologies able to support stakeholders to implement better collaboration approaches and carry out more informed decisions. These decisions should be based on a set of relevant indicators, calculated at district level, capturing the different stages that form the retrofitting process (from the diagnosis to the final assessment). This paper presents a holistic design methodology based on the application of a Multi-Criteria Decision Making approach that allows designing optimised solutions. This methodology is based on the evaluation of a set of District Sustainability Indicators while proposing an Integrated Project Delivery method improving the communications among stakeholders and, therefore, the decision-making process.

Background Positive Energy Districts, which incorporate energy planning at the district level, are a pioneering concept for sustainable, smart and climate-neutral urban development. This concept supports creating communities that generate more annual energy than they consume. To this end, integrative innovative solutions for Positive Energy Blocks/Districts and Positive and Clean Energy Districts have been, are being, and will continue to be devised, tested, and monitored for their performance in the “Lighthouse” cities of various EU research and innovation initiatives. This review paper showcases a range of EU projects that were brought together through panel discussions and workshops during two key events: the MAKING-CITY final event (June 13, 2024) at the Innovation Camp in Groningen, and the Sustainable Places 2024 Conference (September 25, 2024) in Luxembourg. Methodology 11 invited projects on Positive Energy Districts and Positive and Clean Energy Districts, and their corresponding case studies aim at exploring innovative strategies and practical approaches to accelerate the transformation of cities towards sustainability and resilience. Participants of the two events have gained insights into cutting-edge initiatives, exchanged best practices, and discussed actionable steps to foster the development and implementation of PEDs/PCEDs in diverse urban contexts. Results and Discussion These projects collectively serve as a portfolio of related initiatives derived from Smart Cities and Communities, the Climate Neutral Cities Mission, and the Driving Urban Transitions funding programs—each targeting different stages in the planning, design, implementation, or operation of PEDs/PCEDs. Conclusion This study primarily highlights how the eleven projects and their case studies collaborate and cooperate by discussing policy recommendations, technological innovations, economic frameworks, and the role of social and local communities. Through these explorations, it seeks to offer insight into the complex and varied domain of PEDs/PCEDs in terms of replication and future steps.

Positive energy districts (PEDs) consist of more than three interconnected buildings that annually produce more renewable energy than what is consumed within the district boundaries. To achieve the annual surplus of energy, implementation of renewable-driven and innovative technologies is needed. However, most cities struggle in deciding what technologies are more suitable for their environment due to the lack of information and experience in a holistic approach. A decision-making tool has been developed within MAKING-CITY, with the collaboration of ATELIER project, to assist in the PED technology selection process, empowering cities with information and recommendations, in line with their district context and city objectives.

The calculation of the energy balance at the district level is complex since it includes a diverse set of loads, technologies, energy carriers, trading interactions between users and external grids (power, district heating/cooling, gas, etc.) and assumptions such as the identification of Primary Energy Factors (PEFs) in different contexts. This research validates the H2020 MAKING-CITY methodology for calculating the energy balance of Positive Energy Districts (PEDs) in two case studies: the cities of Groningen and Torrelago. For each case, the steps defined in the methodology are followed, dealing with assumptions on non-renewable Primary Energy Factors and critical elements regarding the district boundary. This research shows the applicability of the developed calculation methodology for cities in the design phase as well in the implementation phase of PEDs.