Supply of renewable energy sources and the cost of EU climate policy

What are the excess costs of a separate 20% target for renewable energy as a part of the EU climate policy for 2020? We answer this question using a computable general equilibrium model, WorldScan, which has been extended with a bottom-up module of the electricity sector. The model set-up makes it possible to base the calibration directly on available estimates of costs and capacity potentials for renewable energy sources. In our base case simulation, the costs of EU climate policy with the renewables target are 6% higher than those of a policy without this target. The uncertainty in this estimate is considerable, however, and depends on our assumptions about the availability of low-cost renewable energy: the initial cost level, the steepness of the supply curves and share of renewable energy in the baseline. Within the range we explore, the excess costs vary from zero (when the target is not a binding constraint) to 32% (when the cost progression and the initial cost disadvantage for renewable energy are high and its initial share is low). ► Adding a target for renewable energy to EU climate policy causes excess costs. ► These excess costs are evaluated using a computable general equilibrium model. ► Excess turn out to be between zero and 32% of the costs without a target for renewable energy. ► Crucial model elements are the steepness of the supply curves and the share of renewable energy in the baseline.