The aim of this paper is to propose a framework for the evaluation of policy instruments designed to affect development and dissemination of new energy technologies. The evaluation approach is based on the analysis of selected outcome indicators describing the process of technical change, i.e. the development and dissemination of new energy technologies, on the basis of a socio-technical systems approach. The outcome indicators are used to analyse the effect, in terms of outcome, and outcome scope of the policy instruments as well as the extent to which the policy instruments support diversity, learning and institutional change. The analysis of two cases of evaluations, of energy efficiency policy and wind energy policy in Sweden, shows that the approach has several advantages, allowing continuous evaluation and providing important information for the redesign of policy instruments. There are also disadvantages associated with the approach, such as complexity, possible high cost and the requirement of qualified evaluators. Nevertheless, it is concluded that the information on the continuous performance of different policy instruments and their effects on the introduction and dissemination of new energy technologies, provided by this evaluation approach, is essential for an improved adaptation and implementation of energy and climate policy. (c) 2005 Elsevier Ltd. All rights reserved.