Investment in renewables under uncertainty: Fitting a feed-in scheme into ETS

We analyze incentives to invest in renewable energy technologies induced by the overlap of two types of policies: feed-in schemes and carbon mitigation instruments. We find that results differ markedly depending on the specific types of policies in place, reflecting different impacts of uncertainty. As a result, the recent reform to the EU-ETS system that has established the Market Stability Reserve (MSR), effective in 2019, requires to appropriately finetune the direct RES-E support schemes. We show that this may involve moving away from feed-in tariffs towards feed-in premia. Our results suggest that the schemes currently adopted in Germany and in Italy, broadly based on feed-in premia for large generators and on feed-in tariffs for the small ones, could well fit also the post-MSR EU carbon mitigation policy. To the contrary, other countries (e.g. France and the U.K.) may have to modify their support schemes as the MSR will become operational.