Energy poverty remains a pressing challenge in the European Union, with Spain exhibiting one of the highest incidence rates. Despite an ambitious national strategy, over 20% of Spanish households continues to report difficulties maintaining adequate indoor temperatures. This study examines energy poverty dynamics in Spain using longitudinal data from the European Union Statistics on Income and Living Conditions (EU-SILC) covering the period 2004–2023. We distinguish between transient and chronic energy poverty, revealing that 2.6–3.6% of households experience persistent deprivation. Vulnerability is higher among single-person and female-headed households, while education and employment significantly reduce chronic risk. By focusing on household trajectories, this study contributes to a deeper understanding of structural and temporal dimensions of energy poverty, supporting more effective policy design. Spain’s case highlights the limitations of current measures and the need for strategies addressing long-term vulnerability within a just energy transition framework.
