State of the Art on Sustainability Assessment of Positive Energy Districts: Methodologies, Indicators and Future Perspectives

Abstract

The concept of Positive Energy District is one of the main areas of research and extensive applications of the principles of the clean energy transition within the building sector. In the past years, the most widely accepted definitions have focused specifically on carbon neutrality, while several other aspects regarding all sustainability approaches (including environmental, social and economic perspective) were included qualitatively or to a lesser degree. This paper proposes a discussion on the state of the art of the sustainability assessment of Positive Energy Districts, by investigating environmental, social and economic sustainability applications. The three sustainability dimensions are investigated individually first, while discussing methodological insights, key performance indicators used and quantitative results, as well as in an integrated perspective. Finally, the paper describes research gaps and areas for further development on the topic.

The Role of Positive Energy Districts through the Lens of Urban Sustainability Protocols in the Case Studies of Salzburg and Tampere

“…From an energy-focused perspective, a PED is seen as an energy-self-sufficient and carbonneutral urban district. Indeed, positive energy means that energy districts also play an important role in producing excess energy using renewable energy sources and feeding it back into the grid [12,13]. However, widening the perspective, it is expected that PEDs will increase the quality of life in cities, help achieve the COP21 goals, and improve European capabilities and knowledge, becoming a global model [16].…”

“…In this regard, some interesting research on existing tools to support decision-making toward climate neutrality in cities and districts has been already carried out [7]. In an attempt at extreme simplification, it can be said that PEDs must strike an optimal balance between energy efficiency, energy flexibility, and local energy production, in turn also achieving integrated sustainability based on environmental, economic, and social features [12]. For PEDs, several stakeholders such as cities and public bodies, industry and business, research and academia, citizens and civic society, and private and professional stakeholders play a central role in the energy transition.…”

“…Over time, however, it became apparent that financing large smart city projects at the urban level was a complex task, with a huge demand for resources and investment [11]. For this reason, the European community wanted to focus efforts on smaller urban areas, such as blocks, pilot districts, and neighborhoods [12][13][14], towards a widespread and capillary smart land concept to initiate a more functional awareness of the topic by exploiting and incentivizing local co-design according to location [4]. Therefore, as highlighted in the Horizon 2020 projects that initially focused on the energy efficiency of buildings and local production of renewable energy on-site, there has been a broadening of interest in the urban district [9].…”

“…Indeed, in recent years, to support the urban energy transition, the concept has become even more ambitious, moving from highly efficient buildings close to energy neutrality (nZEB) to zero-emission buildings (ZEB) [15]. As a result of this process of reducing CO 2 emissions, the various anthropological actions with the greatest impact have been included, supporting and promoting energy sharing, waste heat recovery, electric mobility, and energy storage, and the scope has been broadened to include the implementation of zero-emission districts or, better still, positive energy district (PEDs) under this heading [12,[16][17][18][19]. Suppose a zero-emission district combines the built environment and its associated services to reduce harmful emissions as much as possible.…”

“…Suppose a zero-emission district combines the built environment and its associated services to reduce harmful emissions as much as possible. In that case, a PED combines the built environment, mobility, and sustainable production and consumption to increase energy efficiency, make the district energy self-sufficient by exploiting energy surpluses, reduce greenhouse gas emissions to zero from its inception, and create added value for the citizens who use, work, and live in these spaces [12,16,18]. PEDs also require integration between buildings, users, energy networks, mobility services, and information systems.…”