More than 70% of Earth’s surface is ocean, and running through it — just beneath the waves — are powerful currents carrying enormous amounts of kinetic energy. Yet marine renewable energy remains a fraction of what wind and solar have become, in part because no one had ever produced a truly global, data-driven map of where those currents are strongest.
That gap stayed open for decades. Then researchers at Florida Atlantic University fed 30 years of real-world ocean measurements into a comprehensive assessment — and what they found off Florida’s East Coast surprised even the people looking for it.
Thirty years of drifting buoys, one global map
The data behind this discovery didn’t come from satellites or computer simulations. It came from buoys — about 1,250 of them, drifting through the world’s oceans for more than three decades, each one tracking where currents go and how fast they move.
Along Africa, elevated densities run down the eastern and southeastern coastlines — Somalia, Kenya, Tanzania, Madagascar, and South Africa all appear on the map.
Researchers at Florida Atlantic University drew on NOAA’s Global Drifter Program, pulling more than 43 million data points collected between March 1988 and September 2021. That volume of real-world measurement — not modeled estimates — is what makes the study stand out. Most previous work on ocean current energy relied on regional assessments or computational models. This is the first comprehensive global picture built entirely from observed data.
The results appeared in Science Daily via the Florida Atlantic University.
Where the currents hit hardest
The numbers off Florida’s East Coast are striking. Waters there — along with those off South Africa — consistently showed power densities above 2,500 watts per square meter. For context, an “excellent” wind energy resource is classified at roughly 1,000 W/m². These ocean currents carry 2.5 times that energy density.
High-power zones don’t stop at Florida. Strong readings stretch northward along the U.S. Southeast coast all the way to North Carolina. Along Africa, elevated densities run down the eastern and southeastern coastlines — Somalia, Kenya, Tanzania, Madagascar, and South Africa all appear on the map.
The broader picture is also encouraging. About 75% of all high-power-density ocean areas — covering roughly 490,000 square kilometers — carry between 500 and 1,000 W/m². That range sits below the peaks off Florida and South Africa, but it remains significant for practical energy generation.
Why shallow water makes all the difference
Raw power density is only part of the equation. Where that power sits in the water column matters just as much for anyone thinking about placing a turbine in the ocean.
Florida and parts of South Africa benefit from a useful combination: strong currents running through relatively shallow water, around 300 meters deep. That depth is manageable — engineers can anchor turbines there without extraordinary infrastructure.
The contrast with other high-current regions is instructive. Japan and parts of South America show lower power densities at comparable depths, reducing their practical appeal. Where currents run strong in deep water — 1,000 meters or more — engineering challenges multiply fast. Advanced mooring systems become necessary to keep turbines stable, and both installation and maintenance grow significantly more expensive.
The depth-to-power-density relationship, as the researchers put it, is a critical variable in turbine placement and design. Finding a fast current isn’t enough. You need one you can actually reach.
Seasons, reliability, and the gaps in the data
Ocean currents aren’t static. They shift with the seasons, and the study tracked those rhythms carefully.
In the Northern Hemisphere’s warmer months — June through August — power densities near Florida, Japan, and northern Brazil tend to peak. That timing lines up with higher electricity demand driven by air conditioning. South Africa follows its own calendar: peak densities arrive in December through February, the Southern Hemisphere’s summer. Ocean current energy could, in other words, naturally track demand cycles rather than work against them.
Reliability of the estimates varies by region, though. Calculations for North America and Japan were highly consistent, confirmed by comparisons with other measurement methods. South Africa and northern Brazil are harder to pin down — sparse data and variable water conditions introduce more uncertainty into those estimates. To sharpen the picture, researchers recommend targeted studies using acoustic Doppler current profilers, instruments that measure current velocity at multiple depths simultaneously and give engineers the precision needed to design submerged turbines for specific sites.
What comes next for ocean current energy
The immediate scientific priority is filling the data gaps. Brazil and South Africa both show promise, but neither has the measurement density needed to support confident engineering decisions.
On the applied side, FAU’s Southeast National Marine Renewable Energy Center is already working to develop technologies suited to Florida’s offshore current. The center’s director has described Southeast Florida as one of the premier locations globally for harnessing ocean current power — and the new data gives that claim a firmer empirical foundation. The study’s energy characterization data was also designed with integration in mind, so engineers working on broader renewable energy planning can evaluate where ocean current power fits alongside wind, solar, and other sources.
What the research opens up is a clearer view of a resource that has always been there, running steadily offshore, largely unexamined at global scale. The currents won’t wait. The question now is how quickly the technology, the investment, and the policy frameworks can catch up to what the data already shows.
CEO
Carlos is an engineer with strong expertise in technical and industrial topics. He previously worked at international companies such as Siemens and is multilingual.
Carlos is an engineer with strong expertise in technical and industrial topics. He previously worked at international companies such as Siemens and is multilingual.