Utilizing the power of the oceans to generate energy has been explored for decades. The reasons are obvious: waves alone produce 32,000 terawatt-hours of natural energy per year. By comparison, the entire world uses around 23,000 terawatt-hours.
But despite scientists’ best efforts, the motion of the ocean has proven difficult to harness.
The challenges are formidable. Wave patterns are unpredictable, seawater corrodes metal generating machinery, and ocean energy is dispersed across multiple dimensions.
But there are some breakthroughs…albeit on more modest scales.
As reported in Scientific American, Portuguese researchers believe they have uncovered how to use ocean waves to power small and more manageable devices: Specifically, navigational buoys.
Notes Scientific American:
“The team turned to so-called triboelectric nanogenerators, or TENGs, which convert wave motion into an electrical current using static electricity—the same principle as rubbing a balloon on a fuzzy sweater to generate charge. At each TENG’s core are two surfaces, just a few square centimeters in area, that can easily become positively or negatively charged. Atop these two stacked surfaces, the researchers place 10 stainless steel balls, about 12 millimeters in diameter, that are free to move around. When their container tilts, the balls roll around and rub the two surfaces together. This builds up a static charge, which can be converted into electricity to power a battery.
“Working in a hydraulics lab at the University of Porto, the team tested designs for TENGs embedded in a one-eighth-scale replica of an oceanic buoy. They placed the model in a wave pool and simulated the five most frequent wave patterns that occur in the seaport in nearby Figueira da Foz, Portugal. The new study marked the first time they have been tested under such realistic wave conditions, Rodrigues says. And it was a success: the swimming-lane-esque TENG design produced a maximum output of 230 microwatts.”
To read the article in its entirety at Scientific American, click here.
August 17, 2021