A GIS-based framework for hybrid offshore wind and floating solar power plants in Australia

Co-locating offshore wind and floating solar energy represents a promising approach to enhancing renewable energy generation while optimising the use of marine space. This study develops a suitability index ( SI ) to identify and map suitable areas for hybrid offshore wind–floating solar farms within Australia's Exclusive Economic Zone. The index incorporates 11 years of hourly data on wind speed, solar irradiance, and significant wave height (Bureau of Meteorology Atmospheric High-resolution Regional Reanalysis for Australia (BARRA) and the Centre for Australian Weather and Climate Research (CAWCR), alongside indicators of resource magnitude, temporal variability, and wind–solar complementarity. The index also considers factors such as bathymetry, wave climate, marine protected areas, and operational thresholds. In addition, a wind–solar synergy index ( WSSI ) was created to quantify the proportion of time that at least one of the resources is available, to determine the measure of operational measure of hybrid reliability. Three planning scenarios, wind-dominant, balanced, and solar-dominant, were analysed to assess how shifting resource priorities affect spatial suitability. The findings reveal a northward shift in optimal sites under solar-dominant weighting, with the Northern Territory, northern Western Australia, and Queensland emerging as prime locations due to their stronger irradiance, favourable complementarity, and calmer seas. Beyond mapping efforts, the study estimates annual energy production (AEP) for the shortlisted sites, thereby linking suitability directly to practical energy yields. Collectively, the developed SI , scenario-based suitability maps, and AEP estimates provide a reproducible decision-support framework for planning co-located offshore wind–floating solar projects that can support the growth of the blue economy. • Offshore wind–solar colocation assessed across Australia's EEZ using GIS. • Suitability index formulated to integrate wind, solar, and wave resource metrics. • Wind–Solar Synergy Index introduced to quantify hybrid resource complementarity. • National and state-level hotspots mapped for hybrid farms. • Energy yields of top sites estimated with industry standards to show potential.