Our analysis shows that the structure and the average level of electricity prices is identical in the scenario without renewables and in the two scenarios at 10% penetration level. On the contrary, at 30% penetration level there are limited periods in which renewables can meet all of demand and thus become the marginal generating technology, which in a competitive market means zero prices. The price duration curve in the renewable scenario is thus strictly the same as in the reference case, with the exception of those periods in which renewables become the marginal technology.