Hybrid offshore solar-wind farms: the potential of integrating floating photovoltaics with offshore wind

Floating photovoltaics (PV) are rapidly scaling up solar power beyond on-land PV. Whilst offshore floating PV (OFPV) is still in pilot phase, its combination with offshore wind could enable an efficient common use of costly transmission infrastructure. This work presents a detailed, quantitative case study assessing the integration of offshore floating PV with offshore wind. Through stochastic generation expansion planning, the optimal distribution of OFPV within a representative Dutch offshore wind farm is determined. In the power collection network, OFPV is best connected to the substation, or to the wind turbines electrically nearest to it. To evaluate the economic performance of the hybrid solar-wind system, its electrical integration with the Central Western European grid is simulated. The study reveals that a considerable amount of OFPV can be integrated in a modern offshore wind farm without hindering the transmission of wind power, with the export cables being the main bottleneck in power transfer, followed by the substation transformers and the array cables. However, this is accompanied by a significant amount of OFPV curtailment. As the capacity factors of offshore wind turbines increase, the remaining transmission gap in their connections, which OFPV can utilise without any transmission expansion, narrows. Finally, cost targets are derived for which the integrated offshore solar system would break even in the analysed case, revealing challenging economic prospects. The work identifies opportunities for hybrid offshore solar-wind farms and highlights key technical and economic challenges to be addressed.