Modeling the transition to sustainable energy using harmony search: A water-energy nexus case in Greek islands.

The islands of the Aegean Sea in Greece represent a unique example for the water and energy interrelation. A great number of them are not interconnected to the main power grid and independent local grids produce power mainly using imported fossil fuels (e.g. heavy oil, diesel). Equally important, water resources' scarcity is an additional challenge, especially during the high-demand, summer months. Thus, in many arid islands potable water is transported from the mainland by means of sea transport, at a significant cost. This approach apart from the additional cost of fuel and water transport, also imposes signicant economic and environmental impact to these idyllic touristic locations. Seasonal variability in power demand and drinking water consumption, fuel price volatility as well as a growing touristic development, impose some additional complexity. The present study analyzes specic island grids of the Aegean Sea. Selected islands are analyzed as case studies over a 20-year period (2016-2036). The developed energy modeling exercise uses a Harmony Search Algorithm (HSA) in its core. The aim is to investigate whether deployment of renewable energy sources (RES) to existing energy production could lead to a cleaner, sustainable system, decrease the current burden to the government budget and support local resources. The aim is to examine whether increased share of RES, battery storage, desalination and their combination could reduce islands reliability on imports, reduce its cost and potentially eliminate the current non-sustainable and heavily subsidized status quo.