Quantification of flexibility from the thermal mass of residential buildings in England and Wales

The increased integration of variable renewable generation into the power systems, along with the phase-out of fossil-based power stations, necessitate procuring more flexibility from the demand sectors. The electrification of the residential heat sector is an option to decarbonise the heat sector in the United Kingdom. The inherent flexibility that is available in the residential heat sector, in the form of the thermal inertia of buildings, is expected to play an important role in supporting the critical task of short-term balancing of electricity supply and demand. This paper proposes a method for characterising the locally aggregated flexibility envelope from the electrified residential heat sector, considering the most influential factors including outdoor and indoor temperature, thermal mass and heat loss of dwellings. Applying the method to England and Wales as a case study, demonstrated a significant potential for a temporary reduction of electricity demand for heating even during cold days. For a scenario envisaged a fully electrified residential heat sector in England and Wales, total electricity demand reductions of approximately 25 GW and 85 GW were shown to be achievable for the outdoor temperature of 10 degrees C and -5 degrees C, respectively. Improving the energy performance of the housing stock in England and Wales was shown to reduce the magnitude of available flexibility to approximately 18 GW and 60 GW for the outdoor temperature of 10 degrees C and -5 degrees C, respectively. This is due to the use of smaller size heat pumps in the more efficient housing stock. However, the impact of the buildings' retrofit on their thermal mass and consequently on the duration of the flexibility provision is uncertain.

Automated summary

The increased integration of variable renewable generation and the phase-out of fossil-based power stations require more flexibility from the demand sectors. Electrification of the residential heat sector in the UK can decarbonize heating and provide flexibility for balancing electricity supply and demand. This paper proposes a method for characterizing the flexibility of the electrified residential heat sector, considering influential factors such as temperature, thermal mass, and heat loss. Applying the method to England and Wales demonstrates significant potential for temporary reductions in electricity demand for heating, even during cold days.