Review of the methods for evaluation of renewable energy sources penetration and ramping used in the Scenario Outlook and Adequacy Forecast 2015. Case study for Poland

On 30th of June 2015 the European Network of Transmission System Operators for electricity (ENTSO-e) published the ENTSO-e Scenario Outlook & Adequacy Forecast (SOAF) report providing information about impact of Renewable Energy Sources (RES) on power system and potential lack of flexibility in power systems of thirty seven European countries. The flexibility is measured using Residual Load (RL) which equals actual demand decreased by solar, wind and must-run generation, and which is covered by dispatchable power units (generally thermal and hydro). According to the report, the RL for Europe is strongly irregular and unpredictable among member states. As a consequence, high generation ramping is forecasted which leads to necessity of high system flexibility. The results are presented as a distribution of the RES penetration including must-run and distribution of the hourly RES ramps. However, the methodology used by ENTSO-e is questionable. This paper aims to review methods of the RES penetration and the RES ramp assessment presented in the SOAF report. The evaluation is performed on the grounds of the authors' critical approach and in a form of comparison of the displayed techniques with the hitherto carried out studies in this field worldwide. Furthermore, information which is crucial for the stakeholders in the power industry is identified and selected. Finally, based on the collected knowledge, the authors present new, augmented method subject to various already developed techniques, as well as the innovative and creative contribution.