Enabling synergies among hydrogen, desalination, and flywheel storage for sustainable island energy systems

Abstract

The reliance of Lanzarote (Spain) on imported fossil fuels and its complete dependence on energy-intensive desalination underscore the need for an integrated approach to sustainability. This study proposes and evaluates multiple scenarios that combine wind and solar power with hydrogen-based storage, desalination (power-towater), and flywheel technology, highlighting the synergies among these elements. By leveraging scenario modelling, we show how surplus wind electricity can be converted into hydrogen (power-to-hydrogen), used to drive desalination processes, and buffered by flywheels to stabilize short-term fluctuations. Key findings from the study show that renewables can supply 87% of the overall electricity demand of Lanzarote with a competitive levelized cost of energy (LCOE), substantially reducing carbon emissions. However, raising the renewables share from 87% to 100% increases the LCOE considerably. When focusing exclusively on desalination, fully renewable configurations also prove feasible, although they produce notable excess electricity that can be redirected to additional uses or stored as hydrogen. The integration of hydrogen storage helps mitigate the intermittent nature of wind and photovoltaic generation, while flywheels provide rapid-response frequency regulation. Overall, this synergy-focused strategy demonstrates a practical pathway toward large-scale decarbonization and water-security enhancement on islands with similar constraints. By aligning water and energy objectives through power-to-X solutions, Lanzarote's case study offers valuable insights into achieving a more sustainable and resilient future.