Energy sustainability is becoming an increasing issue-or rather "the" issue in our society. Often it is reduced to a purely technical problem. Renewable energies and energy-efficient technologies are developed to solve the problem, but finally the end-users will "decide" how much and what kind of energy they are going to consume. This article is targeted on showing the environmental psychological aspects of the change of energy demand and supply. It builds upon a transactional model of human technology interchange and summarises environmental psychological work done during more than 5 years. It refers to the idea of energy sustainable communities (ESCs), shows the development of one example community and concentrates on one aspect of the social dimension of ESCs, the "acceptance of renewable energy technology", its definition and measurement in Germany. (C) 2008 Elsevier Ltd. All rights reserved.