Demand response beyond the numbers: A critical reappraisal of flexibility in two United Kingdom field trials

Domestic demand response – specifically, changing household electricity usage patterns in response to signals – is an increasingly important part of electricity system decarbonisation. Many forms of demand response exist and there is a live question of the most appropriate and fair way to design it, especially regarding which types of household can participate and how. Using secondary qualitative analysis of published trial documentation, this paper compares two UK based trials in low income households whose headline results – kW peak reduction - differed by two orders of magnitude. Using a framework based on flexibility capital, the contextual factors underlying these different peak reductions are examined, and these headline results are balanced against other outcomes of the trials. The analysis examines the technical and social sources of flexibility capital in each trial, who controlled this capital, and for whom it delivered value. This highlights questions to consider when designing demand response, such as to what extent participants should be expected to understand and actively participate, who should control their energy use and the spread of responsibility and liability across facilitating parties. We argue that critical reappraisals of existing evidence are necessary as the terms for consumer participation in the future energy system are being established. There exist important aspects and consequences of demand response that are overlooked if schemes focus solely on how many Watts can be shifted. This is crucial as governments, the private sector and a growing number of other parties test and implement different demand response strategies.