Editorial: Special Issue “Net-Zero/Positive Energy Buildings and Districts”

The important goal of decarbonization of communities and cities has resulted in the emergence of new concepts and implementations of Net-Zero/Positive-Energy Buildings and Districts (NZPEBD) in recent years [...

Positioning Positive Energy Districts in European Cities

There are many concepts for buildings with integrated renewable energy systems that have received increased attention during the last few years. However, these concepts only strive to streamline building-level renewable energy solutions. In order to improve the flexibility of decentralized energy generation, individual buildings and energy systems should be able to interact with each other. The positive energy district (PED) concept highlights the importance of active interaction between energy generation systems, energy consumers and energy storage within a district. This paper strives to inform the public, decision makers and fellow researchers about the aspects that should be accounted for when planning and implementing different types of PEDs in different regions throughout the European Union. The renewable energy environment varies between different EU regions, in terms of the available renewable energy sources, energy storage potential, population, energy consumption behaviour, costs and regulations, which affect the design and operation of PEDs, and hence, no PED is like the other. This paper provides clear definitions for different types of PEDs, a survey of the renewable energy market circumstances in the EU and a detailed analysis of factors that play an essential role in the PED planning process

Towards low-carbon district heating : Investigating the socio-technical challenges of the urban energy transition

Publisher Copyright: © 2021 The AuthorsDistrict 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. Empirically, the study relies on an extensive stakeholder analysis that involved 44 organisations representing technology providers, energy companies, industry organisations, policymakers, local authorities and researchers. The results show that while several stakeholder groups could converge on key issues such as the need to support certain technological niches and the danger of a biomass lock-in, divergences regarding barriers to be removed existed between policymakers, new entrant firms, and building owners. Cities were considered important actors for the implementation of the proposed low-carbon district heating concept. However, they should encourage building owners' participation in demand response schemes, decentralized renewable energy production, and the re-design of local electricity networks to support district heating electrification.Peer reviewe

ICT intelligent support solutions toward the reduction of heating demand in cold and mild European climate conditions

Adopting intelligent solutions in residential buildings for reducing the HVAC energy demand, especially during the operational stages, is becoming more popular. Information and Communication Technology (ICT) devices are often the backbone of such intelligent solutions, since they can enable an easy and intuitive bidirectional communication between energy systems and users and, at the same time, are able to suggest energy saving procedures. These energy saving procedures are mainly suggested when energy hungry behaviors are registered. Particularly, authors of this paper have assumed setting indoor set point temperatures, adjusting ventilation airflow rates and opening windows as energy hungry behaviors to tackle by means of ICT-driven intelligent solutions. Two different localities, namely Helsinki and Milan, have been considered as representative of cold and mild European climate conditions. Results report that adopting ICT-driven intelligent solutions for setting heating setback and indoor set point temperatures and for controlling the mechanical ventilation according to actual people's presence and CO2 levels ensures consistent reductions of energy demand, especially in Helsinki, where mechanical ventilation is adopted. Moreover, if mechanical ventilation does not work properly or is missing, benefits in reducing energy demand can be even achieved by adopting ICT-driven intelligent solutions for advising building users when windows should be opened or closed according to sensed CO2 levels. This is relevant especially in Milan. The adoption of intelligent HVAC–window controls, which enable to turn off the HVAC when windows are opened, does not ensure a significant effect in Helsinki. Instead, this solution is promising in Milan, especially when heating systems with low thermal masses are installed

Positive Energy Building Definition with the Framework, Elements and Challenges of the Concept

Buildings account for 36% of the final energy demand and 39% of CO2 emissions worldwide. Targets for increasing the energy efficiency of buildings and reducing building related emissions is an important part of the energy policy to reach the Paris agreement within the United Nations Framework Convention on Climate Change. While nearly zero energy buildings are the new norm in the EU, the research is advancing towards positive energy buildings, which contribute to the surrounding community by providing emission-free energy. This paper suggests a definition for positive energy building and presents the framework, elements, and challenges of the concept. In a positive energy building, the annual renewable energy production in the building site exceeds the energy demand of the building. This increases two-way interactions with energy grids, requiring a broader approach compared to zero energy buildings. The role of energy flexibility grows when the share of fluctuating renewable energy increases. The presented framework is designed with balancing two important perspectives: technical and user-centric approaches. It can be accommodated to different operational conditions, regulations, and climates. Potential challenges and opportunities are also discussed, such as the present issues in the building’s balancing boundary, electric vehicle integration, and smart readiness indicators