District Energy Concept Evolution: From Positive Energy Districts (PEDs) to Positive Clean Energy Districts (PCEDs) – What are the main considerations from annual surplus energy to climate neutrality?" Merve Mermertaş and Beril Alpagut, Demir Enerji

There are ongoing discussions regarding the formalization of Positive and Clean Energy Districts (PCEDs), including both the definition itself and the establishment of clear boundaries for these districts. The PCEDs concept arose from the earlier extensively discussed term – PEDs (Positive Energy Districts) – which means the district generates more energy than it consumes through a combination of renewable energy generation, energy efficiency measures, smart grid technologies, and shares the surplus energy to the power or heat grid.

Due to the increased efforts on energy transition caused by energy severity around the globe, PED-related literature and projects have been developing for more than a decade now towards renewable energy and energy flexibility. Although the key common issue for PEDs and PCEDs is to reach a positive energy balance in a district, there is no commonly agreed establishment on the “clean” concept for PCEDs. Based on the analytical components that define PED research (Alpagut et al., 2021)*, new components on district environmental context are being introduced for PCED evaluation.

Therefore, the main aim of this paper is to define the PCED concept and delve into the discussions on what exactly constitutes a PCED and how its assessment methodology is defined. The study behind this paper depends on the NEUTRALPATH Horizon Europe Missions Project (Grant Agreement No. 101096753) that paves the way toward climate-neutral cities by developing PCEDs. Climate neutrality, the state where human activity no longer contributes net greenhouse gas emissions to the atmosphere, is a critical goal for mitigating climate change. Achieving climate neutrality in urban districts necessitates a more nuanced approach than solely achieving a positive energy balance within PCEDs.

A clear understanding of the crucial role of Global Warming Potential (GWP) allows us to consider this by incorporating the impact of all different gases on the atmosphere for all life cycle stages. Life Cycle Analysis (LCA) emerges as a vital tool for assessing the GWP associated with each stage of a district’s life cycle. By evaluating the GWP impact of activities ranging from construction material selection and transportation to operational energy use and end-of-life management, PCEDs can pinpoint areas harboring significant potential for GWP reduction. This approach can ensure that PCEDs not only achieve a positive energy balance but also demonstrably contribute to mitigating climate change.

While the GHG emissions from the district sources, congestion in transportation, and pollution are important concerns for climate neutrality, assisting in maintaining the city’s natural urban environment with ecosystem considerations is also crucial. Cities globally are now confronted with climate-related crises such as heatwaves, floods, and droughts. Therefore, we need to consider new components related to climate for the assessment of district-scale PCED developments. Building on the PED components previously defined in the article (Alpagut et al., 2021)*, this paper identified new criteria for PCED developments. GHG emissions, air quality, land surface temperature, waste production, carbon storage areas, precipitation, biodiversity, water resources, noise pollution, and natural hazards are the newly discussed components that can be considered sustainably for PCED developments. By examining each new component, a reiteration of the importance of a holistic approach throughout the entire PCED life cycle and how to contribute to achieving carbon neutrality on a district scale has been emphasized.

*Alpagut, B., Romo, A. L., Hernández, P., Tabanoğlu, O., & Martinez, N. H. (2021). A GIS-Based Multicriteria Assessment for identification of positive Energy Districts boundary in cities. Energies, 14(22), 7517. https://doi.org/10.3390/en14227517

Contributing projects:

• NEUTRALPATH

Session Chair:

Merve Mermertaş, Demir ENERJİ – NEUTRALPATH Project – Beril Alpagut, Demir ENERJİ – NEUTRALPATH Project