The fulfilment of the aims set by the European Union in the deployment of renewable energy sources for electricity generation (RES-E) has counted and must continue to count on public funding from the member states, which promote private investment in this type of facilities. This funding guarantees a cost-oriented remuneration which, being higher than the market price means an additional cost to the electricity system. With the aim of minimizing the economic impact as the weight of RES-E in the electricity mix increases, the generation costs of renewable units must approach those of the market, which are expected to increase according to the fossil fuel price forecasts. The present study analyzes both the RES-E development and deployment in Spain and Germany, two pioneering countries worldwide and with very similar electricity systems. Based on their national action plans and a simple model, this analysis approaches the RES-E surcharge, comparing and contrasting the results obtained in both countries. (C) 2013 Elsevier Ltd. All rights reserved.