A methodology for calculating the overrun cost to the Spanish electricity system caused by the large overshoot of the PV power targets under the RD 661/2007 is here presented. The elements influencing the cost have been identified, which has allowed proposing different scenarios for its possible evolution. Applying the same methodology, the range of savings achievable by the new energy policy developed in 2010-2012 to reduce this cost has been quantified. Inverting the point of view, the profitability reduction that these energy measures might have caused on the PV facilities has been also assessed. The conclusions obtained from the case of four specific facilities may give some insight about the general economic effects on the installations of the 2010-2012 new energy policy, and the consequences for the investors when the inadequacies of the regulatory schemes are tried to be corrected ex-post. (C) 2014 Elsevier Ltd. All rights reserved.