Alternative results are presented for a more ambitious scenario in which the proportion of renewable sources increases from 20 percent in 2010 to 50 per cent in 2025. The REN 21 study examines the potential for renewable energy sources for electricity generation, heat and cooling, and transport fuels. The corresponding figures, at the regional level, are given below in Figure 6/ In the basic version of the model, each country within a region is assumed to adopt the same mix, as determined by the regional potential.