Wave Driven Generators

nickovs writes "The BBC report that the worlds first commercial power station powered by ocean waves has gone on line. Built by WaveGen, who have issued this press release, the system uses the swell from waves reaching the shore to force air through a Wells Turbine which has the neat property that it turns the same direction irrespective of which way the air flows through it. According to WaveGen "It has been estimated that if less than 0.1% of the renewable energy available within the oceans could be converted into electricity it would satisfy the present world demand for energy more than five times over". Now wouldn't that be nice?" Nice trick.

Re:Tidal generators are the stuff dreams are made

pose no such risk
The cost line - say the 100 meters centered where water meets land - is a very important natural space. As you mentioned Dams can block spawning runs ect, but this plan also has a very negative effect of destroying that coast line which seabirds, turtles, rodents, mammals ect ect use. The waters edge is used by many animals - the habitat lost if you lined the coasts with this type of generator would be immense. Animals need a variety of different spaces - and removing coast lines destroys a vital, independant, specific habitat.

I would be very much in favour of renewable, clean sources of energy being developed - this I feel is a very exciting opportunity and technology BUT what really has to be addressed is the flagrant overconsumption in NorthAmerica. We can increase the amount of power 'till the cows come home' and create it in many clean/viable ways, but when you analyze the issue this does not address the root problem it simply masks it.

Taken from this months Adbuster [adbustesr.org] magazine: ...Storms are growing more intense, more frequent. And --Surprise, surprise -- it has something to do with all that buying. As a standard rule of thumb, spending a dollar in our economy uses about a liter of oil. for manufacturing, shipping advertising, running whatever item you've purchased. Not every purchase is equal, obviously. Buying a used bike at a garage sale is different from buying a Ford Exploiter. But as a rule of thumb it works. If you spend, you heat: Hurricanes ' R' Us. Ask yourself these two questions if you want to understand the physical constraints we face: could the six billion people now inhabiting the Earth (soon to be ten billion) all consume like middle-class Americans without overwhelming the planet? If we keep consuming in such a fashion, will they want to try?"

Later it continues:

"...before he went off to Rio de Janeiro for the 1992 Earth Summit, George Bush the Elder said that while he was willing to talk about the environment, "the American way of life is not negotiable." His successor, Bill Clinton, remarked famously that "it's the economy, stupid." Everything we see around us reinforces that message of inevitability: cars get larger each year, and homes too"

This is a root issue to be concerned with.

The Power of Sex

Perhaps a similar generator could be attached to your waterbed, so when you and your S.O. are ****ing, the lights stay on.

Oh, yeah. You don't want the lights on. So much for that idea.

Re:Wave Generators

Indeed. The Bay of Fundy (yes, you nailed the spelling), which lies between Nova Scotia and New Brunswick (near Maine, for the Canadian geographically-challenged) is home to the highest tides in the world. Some 100 billion tons of water is pumped in and out of the Bay twice a day, every day. It is also the home of the only tidal energy plant in the Western hemisphere.

The Bay of Fundy does produce energy at the Annapolis Royal energy plant, but it only amounts to about 18-20 gigawatts, which equals out to about 1% of Nova Scotia's entire energy use. (Not a lot, in other words.) At last check, it is believed that some 3000 gigawatts of electricity could be produced worldwide through tidal power.

The main problem with tidal power though is that it requires a great difference between high and low tides, at least a 5 m difference. (The Bay of Fundy's high/low tide difference is 17 m.) There aren't too many places around the world with those kinds of tides. Plus, there's the downside that the energy can only be gathered every 12 hours because of the tides.

On the other hand, there are tons of places with waves. Hell, most of the planet is covered with water, so that makes for a lot of beaches. From what I've read, the technology is rather different from the tidal energy used at the Bay. (But then again, IANA hydroelectric expert.)

Since I'm a Nova Scotian, for some reason I know this stuff. Damn Nova Scotian Bay of Fundy propaganda.

J

Re:won't happen, yet...

he bottom line is that alternative fuel will not be used to its potential until it becomes cheaper than traditional power.

You forgot to add that it will never become chaper than traditional power unless omone starts buying it now. Any technology needs its early adopters to get off the ground. Look at HDTV, is it worth paying $10000 for a new TV? A few people might say yes, and this drives the price down as more competition pops up and economies of scale drive the price down. Same for power technology, Wind power started in the 1970's as a potential power technology, but it was damn expensive, like 30-40 cents a kWh, while conventional coal power was on the order of 3-6 cents a kWh. Some people though the technology was good, and they bought it anyways. Now Wind power is about the same cost as coal power, maybe a little more expensive, and adoption of wind is starting to take off. Wind power installations have grown about 30% a year for the last couple of years and even more as prices come down further. My point is that the fact a commercial installation of wave power has finally become a reality is a big boost for the technology. Even if its more expensive now, the very fact that people are buying into it is a good sign. If enough do, eventually the price will come down, after all, waves are free, coal and oil are not. At the point that wave energy becomes cheaper to install than a new coal power plant, the technology will take of. It may take 20 years to get things ramped up, but it will happen.

re:Environmental impact...

That seems backwards to me. Removing kinetic energy from the ocean would lessen such effects, I would think. (Am I missing something basic here?)

It would lessen or almost eliminate erosion at the area where the waves _would have_ hit. That's gotta be good for people living there, right?

I think the only people who would bitch about this are the surfers, dude. Total bummer.

Plus if the figure quoted is acurate, 0.1% of the ocean's kinetic energy being able to power the planet - that's a pretty small amount of the total. Plus we already alter our weather in weird ways just by building cities (take a meteorology class - it's an eye-opener!).

I say go for it. It's gotta be better to be powered by that than by what we are now. Take that, windmills, biomass power plants, geothermal, and solar, and it's very technically feasible to power the whole planet without anywhere near the amount of pollution we currently produce. It's just that it's so much cheaper to do it the dirty way. *sigh*

Quite wrong, sorry

Your concern is that removing kinetic energy from the waves will cause unwanted harm.

Can't happen.

As a wave hits the coastline, it starts to break up. Eventually, it spills over itself and the wave ends. This is the point of zero remaining kinetic energy, and the point of maximum potential energy. The wave retreats, as always.

From what I can tell, this technology uses both kinetic and potential energies to generate electricity. However, it doesn't remove any more energy than the wave would remove on its own. There is absolutely no way that the climate would be harmed by having a man-made structure remove the same kinetic and potential energy from a wave, that it would lose without man's help.

Should work VERY well for the U.S.

Oh, man! Yeah, it "only works on the coasts," but do you know what percent of the population (and therefore power consumption) lies along the coasts here? Okay, I don't know the percentage either, but it's alot. If, say, 10% of coastal power consumption could be replaced with this kind of technology, that would still save a LOT of carbon-based fuel and therefore pollution.

I like this kind of technology because it seems to be taking advantage of apparently perpetual motion. Of course the oceans aren't literally in perpetual motion, but it's as close as we come.

Can it calm harbor chop?

If these thing can have the same sort of effect as the chop reducing things they put in fancy swimming pools, people might really want to install them.

I can just imagine Ney York harbor without all of the chop, because these things absorb the wave energy. Would be really cool, and save a couple bucks of the city energy bill.

Surfers, lichen protest WaveGen

Just as wind farms in Europe have reportedly altered local weather patterns, would not sapping energy from the sea change the fluid dynamics in areas near endagered choral reefs, etc.?

It sounds silly (as was intended), but the more I think about it, we may look at renewable energy very differently in twenty years. From the long view, renewable energy sources like wind and wave may be much more environmentally sound - but far from the assumed perfection.

The legal questions here are similar to mineral rights cases of the last century. If your neighbor installs a wind farm near your property and suddenly your natural bird sanctuary is ruined, can you sue? We know from case law that it is legally hinky to divert a river onto your property no matter what your purpose (even generating renewable hydropower). Wavegen may have farther-reaching effects on the surrounding environment, slightly ruducing the amount of oxygen in the water, endangering wildlife by changing the way the tides play out in a given hydrosystem.

Something to think about.

now on with the stupid crap... [ridiculopathy.com]

Envinronmental impact...

Anyone know what the environmental impact would be if one removes some of the kinetic energy from the oceans? I could see it maybe changing shorelines, shifting or destroying habitats, in more extreme cases damaging or destroying reefs, and the most extreme altering the global energy flow that takes place via the undersea currents from the equator to the poles, resulting in global weather pattern changes. Great technology if it doesn't bite us in the ass.

Energy isn't free.

Sure it looks nice on paper but that energy isn't created from nothing. Have any studies been done to determine the environmental impact of removing that energy from the ocean? I'm far from a tree hugger but when I see alternative energy sources mentioned, I never see any discussion of the impact. It's as if people think that anything that doesn't burn fossil fuels is automatically eco-friendly.

Jamie

related, detailed article

Wave Energy [ernet.in]

Enjoy.
-Hatta

Re:Wells Turbines

Here is a fairly detailed description [ed.ac.uk]

The short answer is that it uses a variable pitch turbine. The idea is somewhat related to tacking a sailboat.

Tidal generators are the stuff dreams are made of

What the press release doesn't make clear is that Wavegen's generator has actually made its schedule: the 2000 rollout was promised back in 1998. How many technologies do you know which have made their window like that?

What the press release also doesn't mention is how Wavegen's generators don't pose the same ecological threat that other generators have historically posed: the chief alternative is a "tidal fence" which completely blocks off the channel in the same way a dam blocks off a river. And like with dams, tidal fences can disrupt the migration and spawning patterns of fish and other sea creatures, who shouldn't be forced to bear the brunt of human progress upon their tuckered little bodies. Wavegen's generators, as you can see from the diagram [wavegen.co.uk] pose no such risk.

Now, let's just make sure we don't steal too much momentum from the moon and have it crash into the earth. That would put a real damper on any ipo.

Renewable or not?

It seems to me that it is rather hard to pin down exactly what a renewable or sustainable power source consists of. There are plenty of power generation sources that look renewable when used on a small scale, but turn out to not be renewable when used on a large scale.

For example, after having built a few small hydro-electric plants, you notice that you can get loads of electricity out of them for almost no ongoing costs, and you don't end up with horribly polluted cities like you did when you were burning coal. So you say, "Great! Let's go build hydro-dams", and you set off round the country looking for good spots on large rivers to start erecting dams.

Fast forward a few decades. Suddenly hydro isn't looking so exciting. You've dammed up all your large rivers at massive public cost -- it turns out building dams is really difficult. Most of the dams you've built came in over-budget and aren't generating as much electricity as they were supposed to. The eco-systems down river of the dams are trashed because they aren't getting enough water. The eco-systems up river are trashed because they're flooded. When the dam was closed you flooded a bunch of great farm land, and now all the vegetation on that land is rotting under water and releasing tons of greenhouse gasses. But you've still got lots of electricity for the future, right? Wrong. It turns out all your dams are filling up with sediment, and are going to be useless in a few years anyway.

That's when you turn to nuclear ... same deal. Supposed to be cheap, clean and renewable. Turns out to be expensive, dangerous and polluting. The people who told us to pay them to build nuclear plants and who said they'd be safe and cheap don't seem to be home when the plants need to be decomissioned, or when it comes to being legally liable for meltdown risk.

So what above wave power? Well it sounds like there's a pretty good chance that it's going to be a lot less damaging than coal, nuclear or hydro, and we should certainly start using it in wider deployments. We sure could use better alternatives to what we're doing now. But lets not just assume that building wave barriers entirely around every coastal country isn't going to have some environmental impact -- to figure that out you'll need ecologists paid by industry independent organizations, whose opinions will be listened to and not just swept under the carpet (as in the case of Nuclear or Hydro).

Final point -- the real win optimizations here are to decrease our needs for energy by looking for less energy intensive technologies and by reducing the uses that we do have. Anyone still using incandescent light bulbs? And what the hell happened to Green PCs? Those high power PIII and Athlon processors burning up more juice than ever before. What do you think those fans and heat sinks are for?

The incentive for invention of better low-power technologies will be commercial. That means that electricity costs should reflect actual production costs, and that means we have to stop subsidising (non-renewable) electricity generation with taxes.

We also need to stop the growth [vhemt.org] of world population.

Whoo-Hoo!

"this both sucks and blows" -Bart