Challenges and Opportunities in Integrating Floating Offshore Wind

Melinda Marquis, Offshore Grid Integration Lead, National Renewable Energy Laboratory (NREL)
The U.S. grid is being transformed with increasing additions of wind and solar power to reach the administration’s goal of decarbonizing the electric power system by 2035 and to achieve a net-zero-emissions economy by 2050. Meeting the 2050 goal will require direct electrification (switching from non-electric to electric power, such as electrifying transportation) and indirect electrification (using electricity to produce other low-carbon energy carriers, such as hydrogen or synthetic fuels).

Offshore wind power will contribute to the low-carbon energy sources being integrated into the grid at increasing rates to meet the decarbonization goals. This year, the administration announced a first-ever national offshore wind goal of 30 GW by 2030, which builds a path toward 110 GW or more offshore wind by 2050. The U.S. offshore wind energy project development and operational pipeline grew to a potential generating capacity of 35,324 megawatts (MW) in 2020. And states have goals to procure at least 39.3 GW of offshore wind capacity by 2040. Water depths in the U.S. are great enough (>60 m) that 60% of the offshore wind resource requires floating turbines. Floating turbines are required for the Pacific, most of the Great Lakes, and Maine.

Modeling and evaluating the impacts to the grid of large capacities of offshore wind, including 30 GW by 2030 and 110+ by 2050, will be crucial to optimizing its integration. Evaluating the need for transmission expansion and ensuring adequate onshore points of interconnection (POIs), as well as different transmission topologies and technologies, is key to maximizing the benefits of offshore wind power. Understanding and estimating the offshore wind resource, including quantifying the uncertainty, is critical. Lastly, understanding and predicting the impacts of climate change on the resource, as well as the resulting increase in extreme weather events, such as hurricanes and wildfires, is necessary.

Floating offshore wind plants will employ dynamic array cables, cables in deep water columns, floating substations, and possibly remote hydrogen production stations. Mooring system designs to expand cost and siting options (e.g., deep water, shallow water, compatibility with fishing, shared moorings) are all research areas for innovation. This presentation will discuss the challenges that need to be overcome to integrate offshore wind into the U.S. grid, including ensuring adequate onshore points of interconnection and onshore transmission upgrades; optimizing offshore transmission topologies for each region to reduce costs, increase reliability, and minimize impacts to coastal communities, ocean users, and the marine environment; and innovations in mooring systems and storage, including hydrogen production.