Do intentions matter in household solar panel adoption? New evidence

While intentions are likely to play an important role in household solar-panel adoption, most research usually considers intentions and actual adoption separately, creating uncertainty for equitable policy design. Using the UK Household Longitudinal Study, we therefore study the link between stated intentions and actual adoption. We find that nearly 90% of households who had seriously considered adopting solar panels by 2012–13 had not adopted by 2021–22. Interestingly, households who initially rejected solar-panel adoption after consideration by 2012–13 were more likely adopters by 2021–22, compared to those who had not considered adoption at all. Despite these nuances, solar intentions (proxied by serious consideration) exert a robust positive effect on actual adoption, increasing the likelihood by three to seven percentage points – larger than commonly assessed variables such as income or perceptions, which each contribute zero to two percentage points. Moreover, the influence of intentions is largely consistent across income groups. Decomposition analysis further reveals that modest income effects are largely attributable to correlated factors such as renting and age. These findings suggest that policy design uncertainty can be reduced by carefully eliciting household intentions, particularly among younger households, rather than relying solely on income-based eligibility thresholds for energy transitions. • We combine analysis of intended and actual solar-panel adoption for UK households. • 90% who seriously considered solar panels by 2012–13 had not adopted by 2021–22. • However, intentions still have a large positive influence on actual solar adoption. • Modest income influences are mostly explained by correlated factors like renting. • Elicitation of intentions can reduce uncertainty for equitable policy design.