The use of forest fuels has more than doubled in Sweden over the last 25-30 years. Almost a fifth of the utilized energy is now based on forest biomass. Concurrently, real prices of bioenergy have decreased to less than a third of what they were 25 years ago. Some principal driving forces behind this development are identified and discussed in this paper. The origin of this development was equally the result of a foreseen shortage of fibre and a reaction to this vulnerable position, made obvious through the 'oil crises'. Although Sweden has a long tradition of large-scale use of forest energy, 35 years ago she was almost totally dependent on imported oil. Forest mechanisation provided rational solutions to handling small diameter wood and stumps in conventional industrial processes, but also enabled the economical use of such wood for energy. During 3 decades of development, drivers and obstacles have shifted. What started to reduce dependence on fossil fuels was later driven by increased general environmental awareness. An emerging 'green' lobby blocked the development of nuclear power and expanded harnessing of hydropower which were alternative means of self-sufficiency. In the last 10-15 years, focus has changed again. Global concern for climatic change due to emissions of greenhouse gases is a powerful driver, endorsing increased use Of CO2-neutral energy sources. Sustainability, resource cycling and the welfare of future generations are seen as goals for continued development. Ideals and policies do not, however, automatically induce change in regular operations. A set of drivers is identified, that has played the decisive role in practice. These include the direct technical-operational drivers, as well as indirect drivers through market development, taxation and other legislation. (c) 2005 Published by Elsevier Ltd.