Global techno-economic assessment of hybrid offshore wind, wave, and solar power

The large-scale deployment of renewable energy at sea offers an opportunity to combine complementary resources within shared offshore infrastructure. While co-location of wind, wave, and solar energy has been proposed as a means to reduce variability and costs, the global conditions under which hybrid offshore power parks are economically preferable remain poorly understood. This study performs a global, temporally high-resolved, techno-economic assessment of offshore wind, wave, and floating solar power, both as stand-alone and co-located systems. Using hourly ERA5 reanalysis data for the period 2020–2024, energy generation from each technology is modelled, and the levelized cost of energy (LCOE) for hybrid parks is minimized subject to shared grid infrastructure and curtailment. The optimization is performed for two cost scenarios representing present-day and near-future capital expenditure levels. Results show that LCOE ranges from 0.04–0.16 €/kWh under present-day conditions and 0.02–0.09 €/kWh under near-future scenarios. Co-location is rarely cost-optimal in regions with excellent single-resource conditions, but can yield lower LCOE than single-technology deployment in locations with moderate and complementary resources. Negative correlations between hourly energy profiles, even when weak (−0.3 to −0.2), are shown to systematically reduce LCOE in mixed systems. While the optimal technology mix is sensitive to assumed cost levels, the underlying drivers (solar capacity factor, resource availability and intersource correlation) for co-location remain robust. These findings provide a global perspective on where and why hybrid offshore energy systems can contribute to a cost-efficient and resilient future energy supply.