Abstract
The marine environment represents a vast source of renewable energy. Marine and offshore wind (OSW) energy infrastructures can contribute significantly to meeting the growing demand for renewable energy. The OSW developments along the NC coast are underway as shown in Fig. 1 (three leases, one off Kitty Hawk and two in Carolina Long Bay). There is a need to study the synergy between OSW and wave energy as complementary resources. OSW and wave energy can be jointly harnessed to reduce output variability and zero production hours. Sharing common installations can lower Levelized Cost of Energy. Co-located WECs can also extract energy from the waves and shield the OSW installation. At present, the wave energy industry is passing the so-called valley of death in technology development and beginning to acquire the necessary experience to reduce the costs. The OSW industry is reducing operational costs and scaling up turbines to achieve more competitive energy prices. Combined wave–wind systems could represent the right approach to solve both requirements in a symbiotic union. WECs could provide an important operational cost reduction to OSW farms by sharing O&M costs or by being used as shields to increase weather windows for access to the wind turbines. The OSW farms could reduce the energy cost of wave energy by sharing the grid connection, the logistics, and other common infrastructures.
To optimally harvest the joint power from OSW and waves in the OSW lease areas off the Carolina coast, there is a need for detailed resource characterization of wave energy that takes into consideration the diversity of two resources. The purpose of this project is to assess and characterize the combined wind and wave energy resource potential in the OSW lease areas. The teams has followed the following approach to meet the project’s objectives: (1) conducted a thorough survey to identify approaches and standards to assess wave energy resource for combined exploitation; (2) identify and understand the publicly available met-ocean data sources and models (long term wave hindcasts such as WaveWatch III, NDBC data from buoy locations in Fig. 2, Marine Energy Atlas, and others) that enabled high temporal and spatial resolution wave resource assessment; (3) Used the selected datasets to estimate wave power density in kilowatts per meter of wave crest width as shown in Fig. 3 for Kitty Hawk location; (4) Used the data from selected NDBC stations to validate the power density estimates for each location as shown in Fig. 4; and (5) Characterized the combined wind and wave energy resources based on the met-ocean parameters and assessed their correlation and seasonal variability. The team found annual OSW and wave energy potentials of 3.1 and 9.05 GW in Kitty Hawk; 3.0 and 4.07 GW in Wilmington West; and 3.1 and 4.09 GW in Wilmington East. If a fraction of the combined OSW and wave energy resource (~17 GW) along NC coast is harnessed, it is sufficient to power all homes in NC (~ 4 million homes).