Session: 09-09-02: Hybrid Energy II

Submission Number: 156296

Integrated Offshore Wind and Wave Energy: Dynamic Interactions and Economic Potential of Hybrid Systems 

In the global effort to mitigate climate change and achieve a zero-carbon future, renewable energy has become essential. Offshore wind and wave energy are two of the most promising renewable energy sources due to their high energy density, abundant availability, and relatively low environmental impact. While offshore wind energy has reached a high level of maturity in recent years, wave energy remains an emerging, complementary resource with significant potential. Major challenges facing wave energy converters are their relatively high costs compared to established offshore wind technology. Integrating wind and wave energy harvesting devices into a single hybrid system could yield substantial benefits, including increased power generation, smoother power output, overall cost reduction, and improved infrastructure utilization. In this study, we investigate the potential advantages of a hybrid system comprising a floating offshore wind turbine and a heaving point absorber wave energy converter. As case studies, we consider the NREL reference 5MW and 15MW offshore wind turbines for integration with the Sandia RM3 wave energy converter comprised of a float that moves relative to a central column that can be outfitted with a reaction plate. We consider both spar and semi-submersible mooring platforms for the integrated systems. The dynamic interactions between the floating offshore wind turbine and wave energy converter are examined, focusing on critical factors such as platform stability, dynamic response, mooring loads, and power production. We explore how the wave energy converter float motion and an optional reaction plate influence the floating offshore wind turbine stability and energy output under various environmental conditions. It is found that the reaction plate provides additional damping to the spar motion, allowing the float to absorb more energy and thereby increasing overall energy production. A comparative analysis between the hybrid configuration and standalone versions of the floating offshore wind turbine and wave energy converter is conducted, highlighting key performance differences and quantifying the economic implications through levelized cost of energy calculations. Our preliminary results suggest a 38% reduction in the levelized cost of energy for the wave energy converter when integrated with the wind turbine, with no increase in the wind turbine’s levelized cost of energy. This economic assessment evaluates how the hybrid approach might lower overall costs, making offshore renewable energy more competitive. Further results will be presented, quantifying the impact of integrating the wave energy converter with the wind turbine on a shared mooring platform. This analysis will address the hydrodynamic responses of both the wave energy converter and floating platform in different directions, mooring line tensions, annual energy production, and a comprehensive cost-benefit assessment. The results from this analysis offer valuable insights for the design and optimization of future hybrid offshore renewable energy systems, demonstrating how integrated wind-wave platforms can support sustainable energy goals while providing a cost-effective solution for energy production.

Presenting Author: Maha Haji Cornell University

Presenting Author Biography: Maha Haji is an Assistant Professor of Mechanical, Aerospace, and Systems Engineering at Cornell University , where she leads the Symbiotic Engineering and Analysis (SEA) Lab. Her research focuses on designing offshore systems that sustainably extract ocean resources—power, water, food, and critical minerals. Current projects include wave energy converters, offshore hydrogen production, seawater lithium harvesters, integrated desalination systems, and marine robotics, with support from NOAA, DOE, DARPA, and Sea Grant. She earned her Ph.D. in 2017 in Mechanical and Oceanographic Engineering from the MIT–WHOI Joint Program. She also worked as an engineering consultant at ATA Engineering, tackling analysis-driven design challenges across aerospace, robotics, and amusement systems. She holds a B.S. in Mechanical Engineering and a B.A. in Applied Mathematics from the University of California, Berkeley.