Having shown how much energy might be saved through the use of economically worthwhile measures and technologies, researchers and policy makers then find themselves trying to close the gap between current practice and recognised technical potential. The ensuing process of technology transfer is often seen as a process of overcoming 'non technical barriers' which inhibit the realisation of proven technical potential. This familiar approach depends upon a strong conceptual distinction between the social, on the one hand, and the technical, on the other, But does it make sense to talk of technical potential in the abstract? Do people really have technologies 'transferred' upon them? Drawing upon ideas from the sociology of science and technology and on recent research funded by Britain's Economic and Social Research Council, this paper unpacks conventional beliefs about the diffusion of energy efficient technologies and suggests an alternative approach which acknowledges the social structuring of technical innovation. (C) 1999 Elsevier Science Ltd. All rights reserved.