The transition to renewable and smart energy systems is critical to address climate change and reduced energy security, particularly on islands where the negative impacts of both are already being felt. This transition, however, is being delayed by, among others, the lack of islanders’ awareness of the effective use of potential energy transition technologies and practices. This paper studies island residents’ initial awareness and knowledge of energy concepts and technologies, before their interaction with them in the context of the four-year EU Horizon 2020 REACT (Renewable Energy for Self-Sustainable Islands) project. Three European islands, Inis Mór (Ireland), La Graciosa (Spain), and San Pietro (Italy) are studied. The analysis seeks to determine how individual’s initial levels of awareness impacted perceived experiences, usability and desire to continue using REACT’s suggested energy transition solutions, technologies and software. The study employed interviews, Technology Acceptance Model (TAM) surveys, and System Usability Scale (SUS) surveys, to evaluate and assess the REACT’s project participants’ attitudes and awareness towards the project’s energy transition concepts and tools. Interviews were conducted before participants interacted with any energy transition technology or software and provided insights into participants’ initial knowledge, awareness and attitudes while the TAM and SUS surveys were conducted after the participants had interacted with the REACT’s proposed technologies and evaluated their perceived usefulness, ease of use, and overall user experience. Results showed that a participant’s initial awareness and knowledge had influenced their experiences with the deployed energy transition technologies, both positively and negatively. Despite these differing experiences, most participants, regardless of initial awareness and knowledge level, found the technologies relatively useful and expressed a willingness to continue using them. The paper’s findings underline the importance of understanding participants’ starting points in terms of awareness and knowledge when planning and implementing energy transition activities. Energy planners seeking to involve people in the energy transition should work to address low levels of awareness and knowledge before beginning, such as with additional information and training tailored to their potential participants’ starting points. In doing so, energy transition planners and energy project developers and managers can enhance participants’ experiences with transition activities and foster long-term engagement.