As the global demand for electricity escalates, the vulnerability of conventional energy sources has become increasingly apparent. Oceanic resources, which encompass over 70% of the Earth’s surface, arise as promising avenues for sustainable energy production through renewable sources, particularly harnessing the power of ocean currents and waves. Despite their potential, the journey toward marine renewable energy development is still in its infancy when compared to more established sources like wind and solar energy. A significant hurdle that needs addressing is the economic viability and feasibility of identifying optimal locations for ocean current energy projects, a challenge that has previously limited the scope of research in this field.
Historically, many investigations have centered on assessing regional ocean current energy resources, yet there has been a notable gap in comprehensive global evaluations based on empirical data. This gap is now being filled by an innovative study from the College of Engineering and Computer Science at Florida Atlantic University, utilizing over three decades of measured data provided by NOAA’s Global Drifter Program. This pioneering research delivers the most extensive assessment of ocean current energy resources on a global scale, providing insights that may significantly impact energy strategies, particularly for Southeast Florida.
Through analytical exploration of kinetic energy capture potential from ocean currents, researchers have focused on the dynamics of power density and its geographic and temporal variations. The Global Drifter Program comprises approximately 1,250 satellite-tracked buoys deployed across the oceans, meticulously measuring currents and their respective positions. For their groundbreaking study, the researchers methodically analyzed more than 43 million data points collected between March 1988 and September 2021, allowing for a detailed understanding of global ocean current patterns and energy potential.
The findings of the study, recently published in the journal "Renewable Energy," underscore that the waters off Florida’s East Coast and South Africa exhibit consistently high power density levels, indicating prime locations for electricity generation via ocean currents. Remarkably, these areas demonstrated power densities exceeding 2,500 watts per square meter – a figure significantly surpassing the energy density classified as "excellent" for wind energy. The relatively shallow waters, averaging around 300 meters in depth, further enhance the practicality of deploying ocean current turbines in these regions. In contrast, locations such as Japan and parts of South America failed to reveal comparable power densities at similar depths.
In their exploration of ocean current energy potential, researchers discovered that roughly 75% of the identified high-power density zones encompass approximately 490,000 square kilometers of ocean, showcasing energy levels ranging from 500 to 1,000 watts per square meter. This residual potential suggests a substantial opportunity for energy harvesting from ocean currents, particularly in regions characterized by moderate yet significant power densities suitable for sustainable energy production. Dr. Mahsan Sadoughipour, the first author and a graduate research assistant in the College of Engineering and Computer Science, emphasized this point, stating that understanding the variables influencing energy generation estimates—including environmental conditions and measurement methodologies—could enhance the reliability of such evaluations.
The study also identified regions in the Southeast U.S., extending from Florida to North Carolina, as locales with high power densities, exceeding the 2,000 watts per square meter threshold. Simultaneously, the Eastern and Southeastern coasts of Africa, particularly places like Somalia, Kenya, and South Africa, were marked as abundant in kinetic energy potential. Conversely, areas in the Eastern Pacific, including Japan and the Philippines, and parts of Northern South America, such as Brazil and French Guiana, exhibited lower power densities, which hampers the feasibility of ocean current energy projects in those locales.
A notable aspect of the research was the accuracy of power density estimates in areas like North America and Japan, where the calculations were deemed highly reliable, instilling confidence regarding energy potential forecasts. By comparing results with existing studies, researchers confirmed the validity of their findings in these well-studied regions, as power density estimates aligned closely with measurements acquired through various techniques. However, assessing areas such as South Africa and parts of South America proved more challenging due to a dearth of data coupled with fluctuating water conditions.
Dr. Yufei Tang, a co-author and an associate professor at FAU, highlighted that certain regions, particularly Brazil and South Africa, suffer from a scarcity of available data, which limits the accuracy of energy predictions and complicates the overall assessment of their potential for energy extraction. He advocated for the expansion of data collection efforts to refine understanding and unlock the maximum energy potential. For instance, region-specific studies utilizing advanced acoustic Doppler current profilers could yield more accurate estimates of energy production potential for underwater turbines.
Factors such as the depth of the water column and complex flow patterns were also pivotal themes emerging from the study. Areas such as South Africa and Japan, while blessed with high power densities, presented challenges linked to deeper water conditions. Regions with depths exceeding 1,000 meters complicate energy extraction tasks, demanding advanced technological solutions. Dr. James H. VanZwieten Jr., another co-author and assistant professor at FAU, emphasized the necessity of innovation in turbine placement and design owing to the established relationship between depth and power density, which directly affects the efficiency and feasibility of energy extraction endeavors.
Seasonal variations are another critical dimension influencing energy availability from ocean currents. During the Northern Hemisphere’s warmer months (June through August), enhanced power densities were reported in regions such as Florida, Japan, and Northern Brazil—a timely alignment with increased energy demand during this period. Likewise, South Africa experiences its peak power densities during its warmer months from December to February. These seasonal fluctuations suggest that ocean current energy has the potential to coincide with peak electricity demands driven by heightened air conditioning usage, positioning it as a reliable renewable energy source.
Dr. Stella Batalama, the dean of the College of Engineering and Computer Science, reiterated the complexity of ensuring accurate estimates for ocean current energy. She pointed out that critical parameters such as data density, data type, and flow variability directly influence these estimates. The insights gained from the study underline the importance of meticulous consideration of these aspects, and the resulting energy characteristics hold promise for effectively merging ocean current energy into the broader renewable energy portfolio.
This groundbreaking research has been rooteded, in part, by support from the National Science Foundation, the U.S. Department of Energy, and the FPL InETech center at FAU. Emphasizing the significance of their findings, Gabriel Alsenas, director of FAU’s Southeast National Marine Renewable Energy Center, noted that Southeast Florida has solidified its status as a leading location for harnessing ocean currents. He expressed pride in FAU’s role at the forefront of American energy innovation, fostering advancements that enhance regional energy security while paving the way for national energy superiority.
As we pivot towards sustainable energy solutions, the potential of ocean current energy is undeniable. With ongoing research and technological enhancements, the knowledge generated through this study provides a foundational understanding of where and how to capitalize on oceanic power, serving as a pivotal roadmap moving forward.
Subject of Research: Ocean Current Energy Resource Assessment
Article Title: Drifter-Based Global Ocean Current Energy Resource Assessment
News Publication Date: 8-Feb-2025
Web References: Florida Atlantic University, Renewable Energy Journal
References: 10.1016/j.renene.2025.122576
Image Credits: Florida Atlantic University
Keywords
Renewable energy, Kinetic energy, Ocean currents, Power density, Ocean engineering, Environmental methods.
