An ex-post analysis of the effect of renewables and cogeneration on Spanish electricity prices

► Concerns about climate change drive renewable support policies that have a non-negligible cost. ► A careful assessment of their impacts seems necessary, for instance their effect on electricity prices. ► We perform an ex-post analysis of renewable energy and cogeneration on Spanish electricity prices between 2005 and 2010. ► An increase of 1 GWh of electricity production with renewables or cogeneration reduced electricity prices by almost 2€/MWh.