Characterisation of the flexibility potential from space heating in French residential buildings

Demand response (DR) at the building level (also named energy flexibility) will play an important role in facilitating energy systems based mostly or entirely on renewable energy sources. Flexibility is thus deemed necessary to control the energy consumption to match the actual energy generation from various renewable energy sources such as solar and wind power. However, there is lack of comprehensive knowledge about how much energy flexibility different building types and their usage may be able to offer to the present or future energy systems. In this study, the flexibility potential of space heating is characterised among the building stock in France. Five different typologies of buildings were chosen (post-1945, BR 1982, BR 2005, BR 2012 and BR 2020) with different levels of insulation, air-tightness and thermal mass. Building energy simulations were performed, with modulations (i.e. increase or decrease) of the space heating set-point during the heating season. From this study, the large influence of the envelope properties on the flexibility potential was highlighted: the storage efficiency for upward modulations and the rebound rates for downward modulations range from 40% up to 90% in poorly insulated and well-insulated buildings, respectively. This study describes a generic method and provides quantitative data to estimate the flexibility potential for demand response at the building level and to help designing future energy grids

Ten questions concerning energy flexibility in buildings

Funding Information: The authors are key collaborators in the IEA EBC Annex 82 project. Dr. Li leads IEA EBC Annex 82 “Energy Flexible Buildings Towards Resilient Low Carbon Energy Systems.” Mr. Satchwell researches utility regulatory and business models that achieve greater deployment of energy efficiency, demand flexibility, and other distributed energy resources. Prof. Finn investigates demand response measures in the residential and commercial building sectors. Senior researcher Christensen researches the role of users in smart energy solutions and low-carbon energy transitions. Prof. Michaël Kummert's research focuses on modeling and control of building-scale and community-scale energy systems to optimize energy flexibility and resilience. Dr. Le Dréau researches energy flexibility of buildings both at building and district scales, develops occupant behavior models and prediction techniques related to flexibility. Dr. Lopes is involved in two international projects funded by the European Union's H2020 programme where he is developing and applying energy flexibility characterization methodologies and optimization algorithms in several demonstration activities. Prof. Madsen leads a national research project ‘Energy Flexible Denmark’ and he focuses on grey-box modeling, digital twins, forecasting and control for smart buildings in smart grids. Dr. Salom research works focus on zero/positive energy buildings and districts and their interaction with energy infrastructures being involved in several international projects. Prof. Henze researches model predictive and reinforcement learning control and data analytics for the integration of building and district energy systems with the electric grid. Mr. Wittchen research works focus on zero/positive energy buildings and districts and implementation of European legislation on building's energy performance. Funding Information: The authors acknowledge the many organizations that directly or indirectly supported the completion of this article. We acknowledge the European Commission for the ARV (grant number 101036723 ), Syn.ikia (grant number 869918 ), Hestia (grant number 957823 ) projects; the Danish Energy Agency for supporting the Danish delegates participating IEA EBC Annex 82 through EUDP (grant number 64020-2131 ); Innovation Fund Denmark in relation to SEM4Cities ( IFD 0143–0004 ) and Flexible Energy Denmark ( IFD 8090-00069B ); the Building Technologies Office, Office of Energy Efficiency and Renewable Energy, at the US Department of Energy , under Lawrence Berkeley National Laboratory (contract number DE-AC02-05CH11231 ); the Center of Technology and Systems (CTS UNINOVA) and the Portuguese Foundation for Science and Technology (FCT) through the Strategic Program UIDB/00066/2020 ; Research Council of Norway in relation to Research Centre on Zero Emission Neighborhoods in Smart Cities - FME-ZEN (No. 2576609 ) and FlexBuild (No. 294920 ); the AGAUR Agency from the Generalitat de Catalunya through the project ComMit-20 ( 2020PANDE00116 ); the National Science and Engineering Research Council of Canada (NSERC Discovery Grant RGPIN 2016-06643 ). Publisher Copyright: © 2022 The AuthorsDemand side energy flexibility is increasingly being viewed as an essential enabler for the swift transition to a low-carbon energy system that displaces conventional fossil fuels with renewable energy sources while maintaining, if not improving, the operation of the energy system. Building energy flexibility may address several challenges facing energy systems and electricity consumers as society transitions to a low-carbon energy system characterized by distributed and intermittent energy resources. For example, by changing the timing and amount of building energy consumption through advanced building technologies, electricity demand and supply balance can be improved to enable greater integration of variable renewable energy. Although the benefits of utilizing energy flexibility from the built environment are generally recognized, solutions that reflect diversity in building stocks, customer behavior, and market rules and regulations need to be developed for successful implementation. In this paper, we pose and answer ten questions covering technological, social, commercial, and regulatory aspects to enable the utilization of energy flexibility of buildings in practice. In particular, we provide a critical overview of techniques and methods for quantifying and harnessing energy flexibility. We discuss the concepts of resilience and multi-carrier energy systems and their relation to energy flexibility. We argue the importance of balancing stakeholder engagement and technology deployment. Finally, we highlight the crucial roles of standardization, regulation, and policy in advancing the deployment of energy flexible buildings.publishersversionpublishe

A novel model for evaluating dynamic thermal comfort under demand response events

International audienceSmart thermostats are expected to become the first residential appliance to offer significant demand response (DR) capacity worldwide. Their success will depend, to a large extent, on how people's thermal comfort will be affected by the dynamic conditions induced during DR events. To study and evaluate such conditions, researchers have so far mainly relied on Fanger's predicted mean vote (PMV) and predicted percentage of dissatisfied (PPD) indices. However, Fanger's model is only suited to predict PMV and PPD under steady-state or slowly changing environmental conditions. For the comfort evaluation of transient thermal conditions, there is still a limited understanding of the psycho-physiological phenomena of thermal alliesthesia and thermal habituation/adaptation, which govern the dynamic thermal perception. In this paper, these two phenomena are incorporated, for the first time, into a dynamic thermal comfort model, which is able to predict the percentage of dissatisfied occupants from Fanger's PMV index. The novel PPD is the result of both a static (PMV-based) and a transient (hedonic and adaptive) component. Since the model builds on the widely-used PMV index, it has the potential to be largely adopted by academics and practitioners and greatly improve their understanding of how people experience comfort and discomfort under DR-induced dynamic environments