Large scale integration of renewable energy sources in the Spanish power system. Curtailment and market issues

In Spain, Renewable Energy Sources (RES) have priority of dispatch in the process of scheduling the available power plants to satisfy system load requirements. Nevertheless, some non-RES units must be necessarily dispatched due to security or system constraints. Thus, at any given time, maximum RES production that can be fed into the system is limited. When RES available resource is higher than this limit, curtailments must be applied in order to guarantee system security. Such situations have already occurred in Spain on several occasions of high wind production during off-peak demands. This paper presents an estimation of future RES curtailments in the Spanish power system. The time horizons of the study are years 2016 and 2020. National RES installation objectives for those years are taken into account. Results show that under all the scenarios considered, RES curtailments are expected to occur. Then, the paper discusses different technical and regulatory measures that could be put in place in the Spanish power system with the aim of optimizing the integration of renewable resources.