Small-scale wave-power - free energy from the beach!

Wave power is a much-neglected source of renewable energy.  More consistent and reliable than wind, it is suffering badly from lack of investment.

There are two main focuses for wave-power; off-shore waves, where the rolling action is exploited by floating buoys or the proven Pelamis system, and on-shore systems, where waves are used to push volumes of air through turbines, like the Limpet system, currently running off the Island of Islay.

This project is a proof-of-concept for a micro-scale system, based on the general concepts of the Limpet, that could developed into a useful source of power for remote beach communities, or exploited commercially to charge tourists' gadgets at the beach.

There are three motivations behind this project:

1. Disaster relief / Power-poverty relief.

A device like this (made of light materials) could be delivered as a flat-pack to areas that are deprived of power (through natural disaster or material poverty), and close to the sea.  Although not enough to cook with, it could be used to charge batteries for radios, lighting or cell-phones (there are a surprising number of areas with good cell-phone coverage, and yet no available mains electricity).  The parts for a unit like this are cheaper and lighter than a solar- or wind-based unit, and wave power is usually more reliable than either wind or solar.  It could even be sent as just the turbine unit, with diagrams on how to make the shell from indigenous materials or debris, maybe with a selection of design tweaks that could be chosen from depending on the local beach conditions.

2. Commercial applications.

I can imagine beach-side stalls, the ones that sell sun-tan lotion and trinkets to tourists, could also provide a service charging up tourist iPads, Kindles and phones.  Again, because of the simplicity and low cost of the component parts, it would be easier to fund for an independent start-up in a poverty-stricken area.

3. Education.

For some reason, discussion of renewable resources in the media begins with solar, ends with wind, and mentions nothing else.  Unfortunately, the same is also true in education.

I can tell my students about wave power systems, and show them pictures of experimental or commercial installations, but the only hands-on kits available are all solar or wind-power based.  Having a project like this available encourages younger students to think outside the box, gives them a chance to get hands-on with a real system, and also provides a starter for older students to work on their own projects (this design is far from perfect, and I am really keen to see where other people can take this idea - see the final step).

Step 1: The general concept.

The concept is simple - waves move inside a confined space, cyclically driving a column of air in and out through a turbine (see the animated gif taken from their website).

Islay, where the Limpet system is installed, typically has high-amplitude waves, breaking against a steep cliff/shoreline.

Most people who go near the sea, though, go to flatter beaches with more horizontal motion to the water.  That is what I will be working with.

Comments

[taftncraft]

Not only are wind turbines inefficient and unsightly they kill bats by the hundreds. Bats are an important part of our ecosystem. article:
http://www.scientificamerican.com/article.cfm?id=wind-turbines-kill-bats

[Kiteman]

Er, have you actually read my *wave* power instructable?

[MakeItWithJason]

I LOVE this, man!

[Kiteman]

Thank you!

[aeszok]

Are those... stock Intel CPU fans??? or are those actually turbines? I didn't know Intel made tiny wind turbines...

[Kiteman]

Just stock fans.

[aeszok]

Ah ok, now it makes sense.

[aeszok]

Very nice instructable btw, how many watts do you think something like that would roughly output?

[gen81465]

I apologize if this has already been suggested, but to keep the water, sand and other debris out of the turbines, why not use some type of rubber bladder on the inside of the upper mechanism? As it fills up, it will still push the air out through the turbines, but would keep the debris from reaching sensitive electrical components. Also, to keep the airflow going in one direction only, why not use plastic dryer vent covers? One would be on the inside (opening inwards), and the other on the outside (facing outwards). The vanes open as air goes through one way, but snap shut when it tries to reverse direction. If it works for keeping cold air out of the dryer vent tubing during the winter, it should work fine here, and it's weatherproof.

[gen81465]

For clarification, the dryer vent cover facing outwards would be on the outflow turbine; and the inside one for return air. I hope these are helpful ideas.

[Kiteman]

I have a feeling that the bladder might rob the device of some efficiency. Unless it's very loose?

The vent cover idea is what I was trying to do with the plastic film.

[bigtreehouse]

Love it..

[Kiteman]

Thank you.

[dragonbtv]

further images

[Kiteman]

Yes, that's the installation that inspired me to do this project.

[profgizmo]

This video has 3 different options for wave power:
http://www.youtube.com/watch?v=bEfrtAOMuvk&feature=related

[audreyobscura]

I am now sad I missed the rest of your residency. THIS! is such a cool project.

[Kiteman]

Thank you!

What's even cooler are the constructive comments: I hope folk take up the idea and move it on.

[ehudwill]

Great idea. I really want to try this one.

[Kiteman]

Let me know how you get on - remember to take photos so you can post it.

[DoctorDv]

Awesome!

[Kiteman]

Thank you!

[Tracy_Marie]

Add handles for carrying parts. Make some parts "nesting" for easier transport. Make a storage area for sandbags and a folding shovel. Keep going, I love this concept. I'd try, but disabled old ladies with no knowledge of generators would need a lot of "help". I seriously want to know how it goes.

[Kiteman]

I refuse to believe that age stops you contributing - if nothing else, you can badger the younger folk you know into having a stab at this as well.

[Tracy_Marie]

Not age per say, severe disabilities as well. Besides, I don't happen to have any "younger folk" available at all. My youngest friend is 42 and has his own family to take care of. My care taker is 67 and losing his ability to care for me. However, you will notice that I did use my brains and made a couple of suggestions regarding easier transport. I have also been read some info about those generators others have mentioned so as to become better informed, thus becoming able to make some useful suggestions to Kiteman.

[Kiteman]

:-)

[wndwalker]

remember the childs toy that had a large disk type object that spun around a screw type device that went through it? It was a spinning top.It had a handle that when pushed down the top would spin up and down the "screw" device. Take that same idea, place it in a wave/air tunnel and I think you would have a great electrical producing machine. There are so many variations that could be harnessed to this wave idea that it isnt funny. I actually designed an idea long ago of a turbine that could be placed in a tidal "current" between 2 or more rock outcroppings that formed a tunnel with both ends open and the middle that got tight, a vortex design. The force of the tide coming through this is enormous. A large turbine placed in the middle would produce power at both incoming as well as out going tides. There is a short period when the tide "ebbs", changes direction and goes the other way, usually about 30 min. Other than that, it's a jam up idea. PS the ebb tides have different times up and down the coast, so no generators would be stopped at the same time..giving constant power every where all the time...turbines I believe would be much better than blades from windmills that are currently working under water. just my opinion.

[Edgar]

Great Project, as usual, Kiteman. You deserve a Video, read the Subtitles:

[Kiteman]

That's really cool, and could be reproducible on the hobby/educational scale (thinks; bicycle pump?)

[Edgar]

Simplified, I should think so...
Even not so simplified, using those Refrigerator Gases instead of the Water pressure circuit...

[Tommunbeig]

An excellent project. It reminded me of Stephen Salter of Edinburgh University whose Ducks for generating power in the 1970's from the waves.were 90% sucessful at energy retrieval and conversion. If you are going ahead with a project be very careful that you are not fobbed off with a direct competitor to evaluate your work. The UK government requested the UK Atomic Energy Commision to do the evaluation. They completely fouled the calculations and came out with a result that was less than 0.9%. Eventuaklly they had to admit this, but by then there was another oil boom.

[Kiteman]

I remember, that only hit the mainstream media in the last year or two, didn't it?

[timmyzog]

This is a really cool concept! What about something really simple like using PVC pipe in an L shape. The base of the L could be in the water with large diameter pipe. A few reducers and then a 90 degree elbow could get you to the top of the L. The fan would reside at the top of the L. You could make the top of the L pretty tall to avoid salt water in your electronics. If there wasn't enough volume differential, you could add some Ys and add several bottom sections to increase the intake volume. That might also allow you to design a more stable base. One leg could be filled with sand as an anchor? My guess is that the best power would come from the highest velocity air so the larger the bottom volume and the smaller the top pipe, the greater the output?
Good luck and keep working!

[eoffermann]

This was exactly my first thought! The basic setup would be fairly easy to maintain and transport, leaving only ensuring that the electronics are isolated from corrosion or are relatively corrosion-resistant in manufacture (or ideally, both).

This strikes me generally as a great project - as an avid sailor with a bluewater ketch that I intend to take to the sea with in the next year or so, the ability to generate power in remote locations is a big part of my plans. While I'm anticipating large solar capacity on the boat itself, while visiting remote islands and the like it would be nice to have reliable power generation. I'm fond of this project for laying the groundwork for a nice, portable 'seapower' system.

[Kiteman]

Oh, that's a nice idea!

[glorybe]

Nature does this on its own. Many beaches have a blowing rock. All it takes is a slab of rock that the waves can rush under and a hole in the rock. In mild waves a blowing rock can spray water and air thirty feet upward or perhaps even more. If a tube were placed over that blow hole a fan could be spun with good force.
There nust be video of blowing rocks on the net.

[mgalyean]

Very nice thinking that simplifies the design well. This would make the entire assembly much easier to move up and down the tide mark as the tides rose and fell. Most beaches in the world have tides that span at least a couple of feet vertically and on the "flat" beaches the author targets this translates to dozens of feet horizontally typically. I'm assuming the idea is that the device would be manually moved up and down the slope if needed. But with a tall enough vertical and a long enough horizontal, your design might allow the device to remain in one place throughout the tidal cycle. We are, after all, dealing with water pressure here, not waves directly; just the pressure change as the depth of the water changes with wave action.

[dragonbtv]

I think water is far more better than air as a working flow because of either its quality or its behavior under compression...

[dexterandrada]

I think having several of these wave generators strategically placed to cover low tide to high tide will at least give you constant 24/7 power generation. I will try to recreate this in an exhibit. Very interesting project.

[Kiteman]

An exhibit? Cool, let me know how that goes.