Hybrid Floating Wind and Solar Plants for Small Island States and Remote Communities: Synergy or Wishful Thinking? An Exploratory Study on the Maltese Islands.

Abstract

The current reliance of Small Island States (SISs) and Remote Communities (RCs) on the import of fossil fuels for power generation comprises significant economic, social and environmental burdens. This is due to the high costs incurred to transport fuels to their often-remote locations which also exposes them to fluctuations in global energy prices and any changes in geopolitical relations. SISs and coastal RCs are also very vulnerable to the effects of climate change. Nonetheless, electrifying SISs and RCs is no easy feat due to the considerable technical challenges encountered in extending stable transmission lines to their locations, their financial difficulties and developmental state, the generally high initial costs of renewable energy technologies, the limited onshore space available in SISs, the variable nature of wind and solar resources, the steep continental slopes of SISs and the dependence of their people’s livelihood on their natural environment.

This research seeks to investigate as to whether offshore floating hybrid wind and solar plants may constitute a solution to electrifying SISs and RCs domestically, in a more environmentally-friendly yet affordable manner. This is done by seeking to confirm or dismiss the hypotheses that when compared to separate systems, Hybrid Energy Systems (HESs) can exploit cost synergies due to the sharing of management and infrastructure, reliability (correlation between system output and electricity demand profiles) synergies stemming from the partial balancing of more than one Variable Renewable Energy (VRE) system, and environmental synergies as a result of the occupation of an overall smaller area by the systems. Using the Maltese Islands as a case study, the findings of this study resolve the research question driving this research: ‘To what extent can Small Island States such as Malta and Remote Communities benefit from hybrid floating wind and solar energy systems and how would an optimal hybrid system in Malta look like?’

This is achieved through stakeholder interviews, direct contact with relevant entities, literature review and the running of energy system simulations and optimisation using the Hybrid Optimization Model for Electric Renewables (HOMER) Model under different scenarios and configurations. The techno-economic outcomes and their analyses are presented, analysed and compared primarily using their Net Present Value (NPV), Payback Period (PBP), storage or supplementation capacities they require and their Levelized Cost Of Electricity (LCOE), among other criteria. These are complimented by a series of sensitivity analyses and a short environmental impact evaluation to get a comprehensive understanding of these systems.

The cost and reliability benefits that SISs and RCs may exploit by installing offshore floating solar-wind HESs as opposed to solitary offshore floating solar and wind systems are confirmed in this study. This research also defines the likely format, key components and probable techno-economic performance of optimal offshore floating solar-wind HESs around the Maltese Islands, thus answering the research question. It also outlines several areas meriting further research. Nonetheless, given the specificity of most of the parameters modelled, these results are liable to change with any major technological shifts or site modifications.