Increased energy efficiency will be paramount in mitigating CO₂ emissions from shipping. Paradoxically, previous research has shown that a substantial amount of measures that typically increase energy efficiency, should be cost-efficient to implement. This is often explained in literature in terms of barriers in markets, institutions and organizations. This article is the first of a series of articles from a joint industry project aiming at understanding good energy management practices in shipping companies. It explores barriers to energy efficiency in shipping through a case study of a short sea shipping company in their process to implement an energy management system. An action research design was chosen to contribute to better practice as well as knowledge in the research community. The study shows that work with energy efficiency was not straightforward, and several challenge areas could be discerned: project management capabilities, ship-shore communication, division of responsibilities, access to performance measurements, and competence in energy efficiency. It is proposed that interpretative research methodologies such as action research could contribute to new perspectives on the traditional barrier discourse.