One of the biggest challenges facing the scaling of marine renewable energy is identifying the most feasible and economically viable locations for ocean current energy projects.
A pioneering study from the College of Engineering and Computer Science at Florida Atlantic University using more than 30 years of measured data from NOAA’s Global Drifter Program (GDP) has been reported as the most comprehensive global assessment of ocean current energy to date.
Researchers explored the potential of capturing kinetic energy from ocean currents, focusing on power density estimation and its variation over time and location. The GDP includes about 1,250 satellite-tracked buoys that measure ocean currents and their positions. For this study, researchers used more than 43 million data points from March 1988 to September 2021.
Their results reveal that the waters off Florida’s East coast and South Africa consistently exhibited high power densities, making them ideal for generating electricity from ocean currents. Specifically, these regions showed power densities greater than 2,500 watts per square meters, considered 2.5 times more energy dense than an “excellent” wind energy resource. The relatively shallow waters of around 300 meters deep further enhance their suitability for extracting energy using ocean current turbines.
Image description: An aerial photograph of Cape Town South Africa. Image by Scott Webb / Pexels
High power densities, more than 2,000 watts per square meter, are found off the Southeast coast of the U.S. from Florida to North Carolina and along the Eastern and Southeastern coasts of Africa (Somalia, Kenya, Tanzania, South Africa and Madagascar). Lower power densities are seen in the Eastern Pacific (Japan, Vietnam and Philippines), Northern South America (Brazil and French Guiana), and the Eastern coast of Australia. In contrast, regions like Japan and parts of South America did not show similar power densities at these depths.
Seasonal variations also significantly influence energy availability. In warmer months for the Northern hemisphere (June to August), higher power densities are observed in regions like Florida, Japan and Northern Brazil, aligning with increased energy demand during these months. Similarly, highest power densities in South Africa occurs during their warmer months (December to February). These seasonal patterns indicate that ocean current energy could align well with periods of higher electricity demand associated with increased air conditioning usage, making it a potentially reliable source of renewable energy.