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Power Earth

Nanogenerator Harvests Ocean-Wave Energy (electronicdesign.com) 12

"There seem to be no limits to the ingenious ways that designers are devising to harvest energy or take existing approaches and exploit and enhance them," writes the site Electronic Design: A research team at the Pacific Northwest National Laboratory (PNNL) has developed a contact-separation mode triboelectric nanogenerator (TENG) with a simple structure for harvesting wave energy and powering marine sensors and transmitters.Although this isn't the first cylindrical TENG (C-TENG) — several models are already in use — the PNNL team maintains that this design overcomes weaknesses of those existing ones.
Long-time Slashdot reader RoccamOccam writes that "triboelectrification is the process by which two originally uncharged bodies become charged when brought into contact and then separated." The key is a new mechanism for wave-driven energy-harvesting "TENGs" that can convert the low-amplitude, low-frequency ocean waves into high-frequency mechanical motion for more effective power generation. This new TENG must be able to operate and be triggered by any wave conditions, even in the middle of the ocean where waves have uniform or random low amplitude and frequency.
The researchers tested their process in a 12-meter-long water tank (with "adjustable wave height and frequency," according to the article). The patent-pending device "sustainably powered up an array of 27 LEDs and was able to charge up a capacitor up to 1.8 V for driving an acoustic transmitter."
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Nanogenerator Harvests Ocean-Wave Energy

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  • Like a Nano Doctor [youtube.com] ... :-)

  • Finally we can have some street lights and traffic lights in the seas. The ships were missing this for a long time now.

  • Ringing a bell (Score:5, Interesting)

    by Okian Warrior ( 537106 ) on Saturday July 15, 2023 @02:10PM (#63688525) Homepage Journal

    Line a container with piezoelectric discs (any of the ones you find in those alerter components on PCBs) and then fill it with steel balls, and place this in your maritime sensor buoy. The rocking and jostling action of the waves will generate a considerable amount of energy(*) from this - upwards of 100 volts in some cases.

    The researchers tested their process in a 12-meter-long water tank (with "adjustable wave height and frequency," according to the article). The patent-pending device "sustainably powered up an array of 27 LEDs and was able to charge up a capacitor up to 1.8 V for driving an acoustic transmitter."

    (*) Note: 1.8V is not a measure of energy, it's a measure of the difference in energy between two points. To be useful to the reader, the journalist should have reported power (voltage times current), because anyone who's interested in this will be wondering if they can use it for their system and... does it supply enough power? But I suppose in the mind of a journalist, voltage is the same as power.

    LEDs are typically driven at 10mA and we don't know the color of the LED but since the article mentioned 1.8V we might assume it's a red LED, so roughly half a watt of energy... probably at thunderstorm levels of jostling.

    To enhance the output performance, a soft-contact mechanism between fluorinated ethylene propylene (FEP) and rabbit fur is attached in the FMC-TENG.

    Have to wonder how long such a system will last with a magnet rolling around inside a cylinder partially lined with rabbit fur. In a marine environment.

    • roughly half a watt of energy

      Meant to say "power" here.

      Damn! Journalists confusing terms is infectious!

    • And I thought you were joking about the rabbit fur. The marine environment recommends baby seal fur. Years ago I worked in a high-rise. We would hang a string from the ceiling, weighted with a couple of hardware nuts, to illustrate the swaying sometimes felt in high winds and earthquakes. People would plant a pencil between curtain wall and supports to watch the pencil break with curtain wall flex. I wondered how much power could be derived by large piezoelectrics on building walls, sometimes while wat
    • by AmiMoJo ( 196126 )

      TFA says 6.67 W/m3 peak with a 0.33Hz wave.

      Potentially useful for remote sensors, but you would probably go with solar panels due to them being mature, proven technology and having no moving parts.

  • Furthermore, Feng et al. designed a soft-contact C-TENG with rabbit fur to prevent charge dissipation and to increase the surface charge density on the dielectric layers (20.3 C/m2); this TENG reached a peak power density of 2.71 W/m3 and an average power density of 0.16 W/m3 at 0.1 Hz triggering wave frequency [21].

    The article does not mention that, "some animals, specifically rabbits, were harmed in this patent pending research."

  • At those very low power consumption levels, even a small solar cell should be able to charge a super-capacitor (or a battery) enough during the day to power the devices during the night.

    This wave energy harvesting contraptions looks way more complicated and expensive... especially because it has moving mechanical parts...
  • Just saw an article talking about how the moon and sun have opposing forces. The sun would speed the Earth's spin, but the moon slows it.

    I've wondered if minute energy harvesters, over time, might have an impact we don't realize until it's too late. That we're on the cusp of some balance we don't realize. And we'll throw things so far out of balance we can't forcibly recover. I know...totally new concept there.

    Weather happens from air flow, and also water flow (which is heat flow). We're purposefully s

  • Not said how much power it generates. Not said how it transfers electricity to outside, stationary land objects. Not said about why the heck rabbit fur and how they concluded that was best material for long term and massively scaled production. So basically a fantastic story about nothing.

As long as we're going to reinvent the wheel again, we might as well try making it round this time. - Mike Dennison

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