Ten questions concerning energy flexibility in buildings

Demand 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.