Testing diffusion of innovation theory for decarbonisation using heat pumps and electric vehicles

Decarbonisation requires adoption of low‑carbon technologies for residential heating and transport, and Diffusion of Innovations theory has strongly influenced modelling approaches and policy. We test central propositions of the theory Diffusion for two priority technologies: residential heat pumps and electric vehicles (EVs). Using a nationally representative survey (N = 1,000), we analyse adoption intentions for each technology and examine the associations between adopter category and three classes of theory‑specified predictors: technology perceptions, communication exposure and individual characteristics. We employ pre-registered generalised ordered logistic regression, complemented by exploratory structural equation modelling. Across both technologies, observed distributions of intentions differ from the S‑curve predicted by the theory, with higher proportions of those most resistant to adoption. Positive technology perceptions are generally associated with greater adoption intentions, while communication exposure and individual characteristics are more weakly associated once perceptual factors are taken into account. Structural equation models indicate that communication exposure and individual characteristics primarily influence adoption indirectly, through their effects on perceptions. Comparing heat pumps and EVs reveals broadly similar patterns. By empirically testing Diffusion of Innovations constructs across two technologies within the same population, the study strengthens the evidence base underpinning diffusion modelling and policy analysis, and highlights the importance of addressing perceptual barriers to accelerate residential decarbonisation.