This event, hosted by Nesta and Centre for Net Zero (CNZ), explored the findings of the Heat Flexproject, a field randomised controlled trial investigating the potential of automated heat pump flexibility for managing household energy demand.

The webinar began with an introduction to Nesta and CNZ, highlighting their roles in driving innovation for social good and accelerating the energy transition, respectively. The HeatFlex project, a partnership between the two organisations, aimed to address the crucial question of whether heat pumps could provide flexibility without compromising customer comfort.

Daniel Lopez-Garcia, Research Manager at CNZ, outlined the rationale for reducing peak electricity demand, emphasising its environmental impact and the need to accommodate increasing demand from the electrification of various sectors. He then described the project's simple yet effective intervention: using smart thermostats to remotely adjust heat pump temperatures during peak demand periods. This involved a preheating period, where temperatures were raised to a comfortable maximum, followed by a flexibility window where temperatures were lowered to a pre-determined minimum. This automated approach aimed to maintain thermal comfort while minimising disruption to customers.

The research team conducted a randomised controlled trial involving 43 participants with existing heat pumps. Half of the participants took part in HeatFlex (the treatment group), and the other half did not (the control group). The trial involved 27 HeatFlex events conducted between February 2024 and April 2024, with variations in the timing and duration of flexibility windows.

The first research area, presented by Daniel, focused on customer comfort. Analysis of temperature data revealed that the intervention resulted in relatively minor temperature fluctuations. Preheating increased average temperatures by less than one degree Celsius, and during the flexibility window, temperatures decreased by a similarly small margin. This minimal impact on temperature contributed to high levels of customer satisfaction with the internal temperatures of their homes, with over 80% of participants reporting that they were satisfied with the internal temperature of their home during events (collected by surveys sent by email after each event)..

Oli Berry, a senior researcher at Nesta, discussed the second research area, the acceptability of automation. Through interviews and floor plan exercises, the team found that participants were generally comfortable with the remote control of their heating systems. Notably, some participants did not notice events happening, particularly in households where communication about when events were time was not shared with all of the household occupants.

Oli then presented the final research area, focusing on demand shifting. The team measured consumption at both the household level (using smart meter data) and directly from the heat pump.

The results indicated that households in the treatment group had a 32% lower household electricity consumption than households in the control group. For heat pump consumption, the researchers found that households in the treatment group had a 74% lower electricity consumption than those in the control group. This discrepancy was attributed to the presence of solar panels and batteries in half of the participating homes. Homes with these technologies could draw little to no electricity from the grid during events, masking the reduction in heat pump consumption at the household level.

The presentation concluded by discussing the policy implications of the trial findings. The team emphasised the potential for automated heat pump flexibility to significantly contribute to demand shifting at scale. However, they highlighted two key factors that could moderate this impact. First, interoperability is crucial to ensure that future heat pumps can be harnessed for automated heat flexibility. Second, the prevalence of other low-carbon technologies, like solar panels and batteries, could affect the overall demand shift achievable, as the potential demand shifting for households with these technologies may be smaller than households without them.

The event concluded with a panel discussion featuring experts from CNZ, Smart Energy GB, and Ofgem. The panel explored various topics, including the scalability of heat pump flexibility, consumer engagement strategies for promoting flexibility, and the importance of automation and consumer protection in the evolving energy landscape. Key points of discussion included the need for ongoing consumer education to address misconceptions about flexibility, the importance of designing compelling flexibility products and services, and the balance between automation and consumer choice. The event provided valuable insights into the potential of automated heat pump flexibility to contribute to a more sustainable and resilient energy system.