Improving reliability indices of the autonomous power system of Crete Island utilizing extended photovoltaic installationsImproving reliability indices of the autonomous power system of Crete Island utilizing extended photovoltaic installations Peer-Reviewed Journal Publication Δημοσίευση σε Περιοδικό με Κριτές 2020-03-312020enRenewable energy sources (RES) have significantly helped in meeting the electricity demand of Crete, with their share in the energy balance to account for about 25% of the annual electricity production for the past five years. The contribution of photovoltaics (PVs) has been especially significant for the past three years, offering 10% in the peak demand, during summertime. This paper investigates what the capacity credit would be, i.e., up to what extent increasing existing PV capacity by about 20% can be considered as certain, to avoid installing thermal power units. In order to do so, probabilistic techniques have been applied to quantify the load that the installed thermal units in the Cretan power system should be able to meet at any time. In addition, the effect of the additional PV capacity to power system’s reliability is evaluated, introducing a new reliability index and taking into account actual data, regarding the planned and unplanned thermal units’ maintenance. Two scenarios have been examined using actual hourly data for load demand, PV, and wind production from the island power system of Crete. In the first scenario, the calculations were carried out considering the operation of the Cretan power system in its current state, while in the second scenario it was assumed that the PV production has been increased by 20%. Furthermore, we examine how the maximum value of capacity credit can be achieved as the PV installations are extended. In this regard, there is an upper limit of the additional PV capacity that leads to the maximum value of capacity credit.http://creativecommons.org/licenses/by/4.0/Energies131Fiorentiz_et_al_Energies_13(1)_2020.pdfChania [Greece]Library of TUC2020-03-30application/pdf8.1 MBfree Fiorentzis Konstantinos Φιορεντζης Κωνσταντινος Tsikalakis Antonios G. Karapidakis Emmanouel S. Katsigiannis Ioannis Κατσιγιαννης Ιωαννης Stavrakakis Georgios Σταυρακακης Γεωργιος MDPI Capacity credit Island power systems Photovoltaics Probabilistic analysis Reliability