Oversizing co-locatedwind and solar parks to increase the capacity factor

This paper presents a study on oversizing existing wind parks with solar photovoltaics (PV) parks. Oversizing is done by installing larger capacity than stipulated in the connection agreement with the system operator. We use two years of observed wind power output from 264 operational wind parks across Sweden and modeled solar power output. The results show that the required curtailment and the increasing PV capacity has a non-linear relationship, where curtailment losses are small at first but increase quickly after installing more than roughly 50 % of the nominal contracted export capacity. The average curtailment losses largely depend on the anti-correlation between the resources and the latitude location, where sites with stronger anti-correlation and higher latitude location in general have less curtailment losses. The curtailed power is largely a function of the overinstalled PV, where storages should be rated at approximately 35 % less than the overinstalled PV in order to capture at least 90 % of the curtailed power. Furthermore, the autocorrelation of the curtailed energy is largely unaffected by the amount of overinstalled PV and reaches a low correlation after approximately four hours.