This study presents a two‐stage stochastic linear programming (LP) model to calculate the water value in an isolated hybrid diesel/wind/pumped‐storage power system with high wind power penetration and with a closed‐loop pumped‐storage power plant (i.e. there is no natural inflows in the upper pond), that takes into account in an approximate manner that the start‐up cost of the diesel units depends on the time passed since the previous shut‐down. The proposed model is applied in the power system of El Hierro island in the Canary Archipelago. The water values provided by the proposed model have been used as input for the day‐ahead generation scheduling. The results obtained in the study indicate that the day‐ahead generation schedule obtained when using the water values provided by the proposed model is similar to the one obtained when using the water values provided by a detailed mixed integer LP (MILP) model. The computational time required to obtain the water value with the proposed model is several orders of magnitude lower than the one needed to solve the MILP model.

This paper analyses the contribution of non‐conventional pumped‐storage hydropower plant (PSHP) configurations like variable‐speed pumping and hydraulic short‐circuit, to reducing the scheduling cost and wind curtailment of an isolated power system with a high penetration of renewable energy. Their impact on the system's CO ₂ emissions and generation mix is analysed as well. For this purpose, the next‐day generation scheduling of the power system of the Great Canary island is computed on a rolling horizon basis for an entire year, considering conventional and non‐conventional PSHP configurations and an increasing installed wind power. Different types of start‐ups of the thermal generating units and the opportunity cost of water (water value) are considered in the day‐ahead generation scheduling. The water value is daily updated by using a two‐stage stochastic optimisation model with a two‐week planning horizon. The results obtained show how these non‐conventional pumped‐storage hydropower plant configurations help not only to reduce the power system scheduling cost but also to integrate more wind energy.

Wave energy is one of the electric generation options based on renewable energies, especially suitable for islands due to the energy resource availability and the higher energy cost of energy in its electric grids. The oscillating nature of the wave resource is prone to produce negative impacts in these electric grids when considering scenarios of high penetration of wave energy generation. This study analyses the impact of wave energy generation on the power system frequency for the particular case study of Tenerife Island (Spain). Then, hourly data related to sea states in Tenerife, during a whole year, will be provided to generate an electric power profile, based on a model of a wave energy farm with a specific wave converter type. A previously developed dynamic simulation model of the Tenerife transmission network will be fed with these power profiles and the hourly electric generation and consumption profiles to analyse the system frequency. A complete set of analysis during the whole year will be accomplished in order to determine the number of over‐frequency events according to the grid codes. Finally, some corrective measures will be proposed as conclusions, e.g. energy storage devices, as the most reliable solution to mitigate frequency deviations.