there is an interesting technical sideargument here regarding the deoptimisation of the residual system if vres had to earn their revenue on the market rather than receive fixed remuneration the revenue they would earn would be lower than the average of all the prices during the hours of the year this is because vre production is selfcorrelated and concentrated during a limited number of hours of the year during which processes are particularly low precisely because of high vre production since this effect is precisely proportional to the variability of the vres the negative externality of system deoptimisation would in fact be directly internalised through the price system see nea a however as long as vre receive fixed fits which protect them against this effect the system deoptimisation due to overdeployment of vres from the point of view of economic efficiency continues to impose an uninternalised social cost or technical externality on the electricity system while they can impose highly unwelcome impacts on certain parties eg traditional utilities which may raise issues from a distributional or political point of view they do not as such constitute social costs and rationales for public intervention