Rubber snake harvests wave energy




Seen in the video above is Anaconda, a new system for harvesting energy from the ocean's waves. The 8-meter long, water-filled rubber "snake" is a prototype of a 200 meter version that the developers, Atkins Global, hopes will generate the energy required to power 1000 homes. The device is currently under testing in Gosport, UK and Checkmate Seaenergy hopes to bring it to market by 2014. I was surprised to learn that one of the big challenges to harvesting tidal wave energy is that the mechanical devices don't tend to last long because they get so abused by the ocean. From New Scientist:
(As the Anaconda moves, it forms "bulge waves") similar to those that pass through the human circulatory system and can be felt as the pulse in the wrist and neck, says Rod Rainey of Atkins Global, co-inventor of the Anaconda. When each bulge wave reaches the end of the snake it keeps a turbine spinning to generate electricity.

The snake is made from a rubber-based material similar to that used to make dracones – flexible containers that are filled with diesel or water and towed behind ships for quick and cheap transportation.

Other than the turbine, Anaconda has no moving parts and unlike other wave power devices it needs only one tether to the ocean floor. That lowers construction costs and reduces the need for maintenance – an expensive undertaking in offshore settings where corrosion and accessibility are problems, explains Rainey.
"Sea 'snake' generates electricity with every wave"

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  1. Very cool.

    I’m glad to see this concept is still moving forward after reading about it in the past!

  2. Off topic, but is it just me or does that narrator’s voice really bug anyone else? Something about the way she emphasizes or stresses certain words and syllables is very grating.

    Is this just an idiosyncrasy or some regional accent I haven’t heard before?

  3. Very cool idea…

    But wait just a doggone minute here. Are you telling me that after Exxon Valdez and now in the era of double-hulled tankers, we friggin’ transport fuel around behind ships in rubber tubes?!!! Wha?!

    http://en.wikipedia.org/wiki/Dracone_Barge

    (Reminds me of the Star Trek storyline where it was revealed that ships “carried” cargo in transporter beam “stasis” (like Scotty in “Relic”) — the mass is still there, and the energy it takes to maintain signal integrity, but the physical space to contain the cargo isn’t needed…)

  4. Interesting concept, but this is actually not the first attempt to use a snake-like shape to harvest energy from waves. Google for “pelamis” or see this Wikipedia article.

  5. Ahhh, the world saved by BULGES…

    I like the guy at the computer console with a life preserver on (I’m sure it’s some anal rententive safety mesaure)

  6. 2 and a half questions:

    1. How does the electricity get from the anaconda’s to someplace useful? Underwater cables? or does someone have to take boat out there to swap out the batteries?

    2. will all these floating rubber things cause any problems for whales, sharks, or have any other potentially problematic environmental impact?

    2.5 What about boats? Seems like they’d be pretty easy to run over.

  7. I always wonder about this. I know that the ocean is vast and that the amount of energy in the waves is enormous. If we start using something like this that uses wave energy and we put tons of these things out there, rather than just enough to power 50k homes, is there a chance we could alter wave patterns? I’m sure altering wave patterns a little is infinitely preferable to using nonrenewable, carbon spewing energy sources, but I’ve just never gotten a good answer on that.

  8. I await the day our oceans are littered with these things, and the panic of the day is ‘orbit decay’ after scientists discover we’ve taken too much energy out of the system and the moon is going to crash into the earth.

    Of course I’ll be dead by then, so I’ll be watching from the afterlife, but that won’t make it any less funny.

  9. the simulated video of fields of these things is kinda creepy.

    massive tentacles in the water with cables running back to land with these eerie undulations. seems very matrix-esque kinda scary sci-fi. can we have them painted with nice friendly colors?

    also. not so worried about the lunar orbiting loss of energy, more worried about how this will muck up my skim boarding ride times. … that and when i go crabbing, or build sand castles. seriously.. could be dangerous.

    … also kinda worried about large sums of electricity in the water.

  10. Does anyone know what the cost per kWh is estimated for this? The Agucadoura-Pelamis project looks to be about $.36/kWh but that is a napkin calculation based on the tariff subsidy, which seems pretty expensive.

  11. “I was surprised to learn that one of the big challenges to harvesting tidal energy is that the mechanical devices don’t tend to last long because they get so abused by the ocean.”

    Tidal energy != wave energy

    Tidal energy is a continuous flow of water. Its direction varies during the day. Wave energy is from an oscillatory motion. It has phases of seconds to minutes.

    Erik de Bruijn . nl

  12. 1. zomg the poor moon!! no energy is “removed” from the orbit of the moon, lol. the tubes only displace water pressure already provided by the moon (and much more significantly, the wind). The average head of the ocean drops over a given area (un-noticeably, i’m sure) in order for the tube head pressure to rise, producing a jet in the tube which is directed inland towards the turbine inlets

    2. the turbines can be placed on land, or even float just above the surface, so that there is no electrical energy present in the water itself. if there’s a hurricane or something that could cause many of the cables to fail simultaneously, then surely someone/something will pull a breaker on shore.

    a large amount of these devices placed closer inland would actually reduce storm surge, though maybe not noticeably so

    turbines produce AC power, by default. so no batteries needed, just sea-tight cables delivering free, multiphase AC power easily tailored to connect directly into a neighborhood substation

  13. We need to start getting more EROEI numbers for these gadgets. For the uninitiated, it stands for “Energy Return On Energy Invested”. Historically oil was about a 100:1 ratio, but nowadays it is more like 25:1 (ethanol, by comparison, is somewhere between 1.3:1 and 0.75:1).

    Gadgets like this don’t seem to yield anywhere near that ratio, so “cheap” doesn’t really factor in when we’re talking about fossil fuel replacements.

  14. huh? “Section sponsored by General Electric”

    Never noticed that before. Is this a new thing for boing boing?

  15. @#8 Anonymous:

    is there a chance we could alter wave patterns?

    By definition, this thing is taking energy away from the waves. If you had enough of these things and a single wave ran over them, there wouldn’t be a wave at the other end — these snakes would have taken all the energy.

    But would this affect the tides? I don’t think so — the moon would still be pulling the water up on one side of the Earth, and it would still get there, even if all the energy were sapped out of waves.

    What are waves good for? I don’t actually know. Are there ecosystems that depend of the movement of the waves (not tides)?

    And that’s all besides the fact that I assume that if you calculated the total energy available from the waves and compared it to the total energy Humans use, we would amount to a very, very small fraction of it.

  16. STARFISH @21, no, not a new thing for us. GE is currently sponsoring this category of posts about energy, similar to the way, say, a financial firm might sponsor CNN.com stock market section. GE has no oversight or input into the editorial content though.

  17. Looks like a great idea, but who’s going to clean the insides of those things after a month in the water? They are instant habitat for algae, seaweed, mussels and octopi. Like an old bottle or tire on the bay floor, someone will move into it pretty quickly and the units will become much less efficient without nasty cleansers or LOTs of scrubbing labor.

  18. “I was surprised to learn that one of the big challenges to harvesting tidal energy is that the mechanical devices don’t tend to last long because they get so abused by the ocean.”

    I’m not. Oceans have been destroying man-made things for as long as we’ve been building stuff near oceans.

  19. So your girlfriend rolls a Honda, playin’ workout tapes by Fonda
    But Fonda ain’t got a motor in the back of her Honda
    My anaconda don’t want none
    Unless you’ve got buns, hun!

  20. The moons orbit is not controlled by the tide (the tide is controlled by the moons orbit however), therefore we can’t make the moon crash into the earth by putting in a trillion billion of these things.

    I think the only way we could really affect the moons orbit is to seriously change the mass of either the moon, the earth or the sun. Another possible option would be to create or acquire some kind of other massive object and throw it into orbit around the earth (or moon).

  21. @17 BOBHUGHES:
    Turbines produce rotary mechanical force by default. Whether you get AC or DC in the end depends on if you hang an AC alternator or a DC generator off the output shaft.
    Also – “…easily tailored to connect directly into a neighborhood substation…” Not really easy at all. In the case of an AC alternator output, unless the turbines are always spinning at a constant and fixed rate, you’ve got one hell of a synchronization problem with the AC mains on shore. In the case of a DC generator, you’d need a very non-trivial DC-to-AC inverter, a big and expensive piece of hardware at these power levels. Wind farms do it this way, since the wind, well, changes all the time. Like waves.

  22. So does anyone know approximately how much energy these things actually produce, other than the vague mention of enough energy “to power 1000 homes.”

  23. good idea, however it sounds a bit too risky. i would rather prefer fusion power, but its a bit more expensive and maybe catostrophic. the wave idea can mess up aquatic life as well as be a problem from hurricanes. i think the top scientist should have a round table meeting and discuss power for the future or maybe they did……

  24. @ #26
    I don’t believe these systems are open to the sea. They are closed, which is how they generate the power, by the pressure difference between the sea water and freshwater. The bulge is created, moves down the length of the snake internally and powers a turbine (also internal).
    So there should be no contaminants entering them at any point… until the salt water eats away the rubber shell… at which point the system fails since the pressure can no longer be created, then you have a bigger problem than keeping them tidy.

  25. I would be interested in the long-term durability of these devices. A power-generating system that required too frequent repair and/or replacement would be economically impractical.

    While plastic and rubber may not biodegrade, I have observed that these substances can become quite brittle over the course of a year or two, when exposed to the elements. Perhaps the researchers are using specific materials that avoid this?

  26. i just want to say thankyou for all the info on the anaconda. as i am in the middle of writing a book about how man is destroying the world and the need for alternative energy sources.and found your site very usefull and i will be logging in on more often so again thankyou

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