Despite recent progress, the production costs for renewable electricity remain above those for conventional power. Expectations of continuous reductions in production costs, typically underpin governments' policies for financial support. They often draw on the technology-focused versions of the Experience Curve model. This paper discusses how national-contextual factors also have a strong influence on production costs, such as geographic, infrastructural, institutional, and resource factors. As technologies mature, and as they reach significant levels of diffusion nationally, sustained increases in production costs might be recorded, due to these nationally contextual factors, poorly accounted for in policy-making decisions for price support. The paper suggests an analytical framework for a more comprehensive understanding of production costs. Based on this, it recommends that the evolution of specific cost levels and factors be monitored to locate 'sources of changes'. The paper also suggests policy instruments that governments may use to facilitate cost decreases, whenever possible. The application of the framework is illustrated for the diffusion of wind power in Spain during the past three decades. (C) 2011 Elsevier Ltd. All rights reserved.