acceptable, technically feasible, and regionally relevant. This qualitative study, conducted within the EUfunded HYSTORE project, examines stakeholder perceptions of hybrid thermal energy storage (TES) and demand-side management (DSM) across demonstration sites in Spain, Austria, Sweden, and Ireland. Using twenty-three semi-structured interviews with policymakers, engineers, facility managers, and resident-users, the study explores economic, technical, and regulatory factors influencing adoption. The interviews followed a guide with predetermined topics, enabling structured inquiry while allowing interviewees to freely express concerns, raise new issues, and engage in meaningful dialogue. Thematic analysis reveals that around 70% of participants currently use energy storage — mainly hot-water tanks or batteries. Approximately 86% are familiar with TES, and 16 out of 23 believe TES systems are effective for improving energy management by reducing consumption and costs. Two-thirds of respondents identify photovoltaic panels as the most accessible low-carbon technology. Despite these favourable perceptions, stakeholders cite high upfront costs, limited awareness, integration complexity, and maintenance concerns as key barriers. This study provides a user-centred evidence base for the deployment of TES and DSM technologies, emphasising the need to reduce financial barriers, simplify system architectures, and enhance training and communication for installers and end-users. By grounding technical development in stakeholder experience, the research offers actionable insights for policymakers, industry practitioners, and researchers working to scale sustainable energy solutions across diverse European contexts.