Demand management for load smoothing in small power systems: the case of Porto Santo island

This work assesses the contribution of a reverse osmosis seawater desalination plant, as a controllable load, to smoothen the power fluctuations in a small islanded power system with the contribution of renewable generation (solar and wind production). The mismatch that may exist between energy availability and the energy consumption is one of the main barriers to higher dissemination of renewable generation for cases like Porto Santo island. Being able to deal with the variation of renewable sources may be challenging especially if demand varies in the opposite direction. Demand-side management techniques are one of the tools that may be used for dealing with such mismatch, thus facilitating the accommodation of higher renewable electricity, and at the same time allowing a more efficient operation of the power system. This is even more critical in scenarios in which there are no endogenous resources and the existing power system is based on small size thermal power plants. The proposed approach for managing the desalination plant shows a reduction in the maximum electricity demand on the island and a smoother diagram allowing a more predictable operation of conventional generators. It proves that the option of employing the desalination plant as a flexible demand/load is beneficial for managing the electric power grid of Porto Santo island.