Design optimization of hybrid renewable energy systems under uncertainty - The case of Sifnos island

The European Green deal has set the goal of increasing renewable energy penetration in European countries’ power systems, in an attempt to also reduce their carbon footprint. With regard to this, hybrid systems, combining renewables with energy storage components, have become increasingly popular. Their versatility allows for the exploitation of the complementary features of different energy sources. Hybrid energy systems find great applicability in remote regions that are typically not connected to the mainland power grid, where the energy independence challenge intensifies. In this thesis, we consider the optimization of a proposed scheme in the Greek island of Sifnos, comprising wind turbines, solar panels, and a pumped storage system using seawater, which introduces additional technical challenges to address. The rational design for the main system components is based on two pillars. The first is a multi-criteria financial optimization procedure that accounts for investment costs, energy market revenues and reliability metrics. The second pillar is a novel representation of key uncertainty sources, including two external drivers, namely the wind velocity (natural process) and the energy demand (anthropogenic process), and the wind-to-power conversion (internal process). The latter originates from the deviation of on-site wind power production from the manufacturer’s power curve. The outcomes of the overall stochastic optimization procedure are compared to the mainstream deterministic design approach. In this vein, we employ a comprehensive interpretation of the impacts of uncertainty in hybrid energy system planning.