This report outlines a theoretical framework for describing and analyzing the introduction of new technologies and the development of socio-technical systems associated with such innovations. While the report is largely theoretical in nature, it refers to certain strategic aspects of the development of nuclear, hydro-power and alternative energy systems. The ease with which technological innovation and development occur, the directions they take, and the impacts they have on the social and physical environments depend not only on purely technical and economic factors. Barriers, regulators and facilitators are inherent in the socio-political, institutional and cultural structures within which any attempts at innovation and technological development take place. The final section of the report explores some of the implications of the theory for policy and strategy, including consideration of environmental policy.