Floating Offshore Solar Photovoltaics for Land-Constrained and Diverse Renewable Supply Conditions in the United States and Canada

Energy transition pathways for large continental areas are largely understood to be achievable using a diverse set of onshore renewable energy technologies. Previous research for the integrated United States and Canada energy–industry system indicated that solar photovoltaics (PVs) may dominate the primary energy structure, complemented by onshore wind power. However, societal constraints may require increased supply diversity, and onshore renewable energy may not be sufficient for densely populated regions, especially on the east coast of the United States. The LUT Energy System Transition Model was applied to investigate the role of floating offshore solar PV coupled with offshore wind and wave power when onshore solar PV is limited. The results indicate that, when onshore solar PV is limited to 60% of electricity generation, 434 GW of floating offshore solar PV may be installed by 2050 as part of a hybrid power plant sharing the same grid connection as offshore wind power, which reaches 414 GW of installed capacity, contributing 607 and 1576 TWh to the electricity supply, respectively. In total, 7.4 TW of solar PV capacity is installed by 2050, complemented by 1.4 TW of onshore wind power. Increased supply diversity still leads to a 42% reduction in the levelized cost of electricity, reaching 32.7 €/MWh in 2050. Compared with cost-optimal conditions, the levelized cost of final energy and nonenergy use in 2050 increases by 28% to 52.7 €/MWh. Nevertheless, such increased costs may be justifiable to meet societal constraints, and a diverse power-to-X economy structure for the United States and Canada may still be technoeconomically viable.