Wave power—energy harvested from ocean currents—is likely to be the next big thing in renewable energy generation, so researchers are spending quite a bit of time on new technologies to take advantage of the sustainable energy source. A new device has emerged that taps into hard-to-reach low frequencies of the ocean wave energy spectrum, utilizing energy that most harvesters cannot access. This makes it possible to draw even more power from calm, slow-moving seas, amplifying the potential of wave energy.
Zhong Lin Wang of Georgia Institute of Technology created the new device to capture “blue energy,” another name for wave power. It’s a hybrid system that combines the efforts of two generators: an electromagnetic generator (EMG) and a triboelectric nanogenerator (TENG). EMG systems are the most common in existing wave energy harvesters, because they target high frequencies of fast-moving ocean currents. The more recently developed TENG technology is the one that taps into the lower frequencies, making Wang’s wave energy generator more efficient than existing models. By combining the two approaches, the generator captures a broader spectrum of ocean energy.
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“The TENG has the unique advantage of high output voltage, and its output power is linearly scaled with frequency, making it ideal for harvesting low-frequency energy,” Wang told Phys.org. “On the other hand, the EMG’s output power is proportional to the square of the frequency, so the EMG is ideally suited for harvesting high-frequency energy. At low frequency, (< 5 Hz), the effective output of the TENG is much higher than that of the EMG.” The research results were recently published in the journal ACS Nano.
Images via Saltvand/Flickr and Zhong Lin Wang