Embedding energy flexibility capability in air source heat pumps via third-party control: Insights from a field trial on residential buildings in England

This research investigates energy flexibility in residential building clusters transitioning from gas boilers to air source heat pumps, within the broader context of rapid decarbonisation of both building stock and electric grid in the UK. The study field trialed a scalable control approach embedded in heat pumps, as part of the EPSRC funded project "LATENT: Residential heat as an energy system service". The project explores a flexibility paradigm where aggregators and Energy Service Companies (ESCOs) partner with installers and manufacturers to leverage small-scale flexibility sources, to enable swift flexibility deployment in clusters of buildings. Flexibility events were scheduled for ESCO customers in Southern England during typical UK electric grid peak hours, using an intervention and control approach across customer groups. Findings reveal insights into third-party control operation, events duration, override requests, achievable flexibility and user behaviour/comfort preferences. Peak shaving strategies implemented resulted in an average power reduction of 88.2% across events with a maximum demand reduction of 1.581 kW, averaged throughout the cluster of buildings. Override requests occurred in only 2.7% of potential cases, with events lasting from 30 to 120 minutes. The study also assessed temperature dependence in flexibility performance at the cluster level. Results indicate the feasibility of longer energy flexibility events, contingent on a more advanced analysis of technical and social constraints. In conclusion, the research emphasises the significance of conducting field trials to showcase potential for energy flexibility solutions in optimising the operation of electric infrastructure.