Tidal Power a Reality 346
updog writes "Here's an interesting story about a city in Norway using an underwater
turbine to generate electricity. It doesn't produce much power (300kW) but maybe it'll pave the way for these types of power plants. Maybe one under the Golden Gate someday??"
Another reason to bring our other 2 moons nearer.. (Score:2, Funny)
Then profit!
Yo da man (Score:4, Interesting)
In order to generate a kilowatt hour it would be necessary to
displace33000 cubic ft at %100 eff. assuming a tidal effect of
1 ft per hour. 1000 watts divided by a hrspwr [776 foot-lbs.]
times 550 times 60.. It would require a tidal pool 10 times
larger than the town it was designed to power just to supply
a minimum power per unit..
.
A system infinitely more effective is the "Wave Rocker"..
which has been going nowhere in the decades since its
inception. There are two types;
1) Tethered to the sea floor, as the waves come in, a float
rises & sinks with each wave. The tether cable turns a generator
as the float moves up & down.Its as though one ties a boat to a
pier, when the wave hits the boat it will snap the line if it has no give.
2) a boat whose length is eqal to 1/2 wavelength of the waves.
As the boat rocks in the surf, a bowling ball rolling around on the
deck pulls a lanyard wraped around the generator shaft.
.
Oilmen will tell you the floats collect barnacles & its costly
maintaining them. Anti barnicle paints containing capsicum
[chilli peppers] keep the little suckers at bay however.
.
Speaking of oil interests, how the hell the republicans could take
any seats in congress after Dubyah blew 10 terabucks in
the stockmarket I'll never know. He blew 600 million dollars of
investor money just trying to screw Martha Stewart,[ can't say
he's a cheap date but it wasn't his money.] They want Martha to
roll over on that Cancer doctorWelasec[?] because cancer
protects oil profits from nuclear power.
Enron is the Vampire of the stock community, the only way it can
be killed is by the government stopping trading on this stock.
It owns immensely profitable pipelines that replace revenue as
quickly as they can gamble the money away. If any of those
gambles were allowed to come in it would have doubled the
stock value. Enron deliberately created thousands of jobs
which were all trashed by Dubyah when he demanded Enron
cease functioning.
.
He blames the CEOs who have created America's wealth
& cites $100 million dollar bonuses. Personally if I were a CEO
& I brought in a billion dollars in new business a %10 bonus
wouldn't be excesive, it would be mandatory. Never having
worked a day in his life since the Skull & Bones made him
a "made Man"; being reimbursed for ones labors in a country
where life is measured in dollars doesn't mean anything to him
SPQR
Warning! (Score:5, Funny)
graspee
Re:Warning! (Score:2)
Deep ones generating electricity?
Who modded this off-topic?
Someone should read their Lovecraft.
Re:Heh eh ah ha eh (Score:3, Insightful)
Anybody know of a way to manualy enter a domain to block images from in Phoenix? Having to go there and right click the image to not have to see it again... it's like killing Hitler as a baby, only with gaping assholes. *shudder*
Environmental concerns (Score:5, Insightful)
Repost! I remember now. (Score:2, Interesting)
Bay of Fundy, Anapolis Royal Nova Scotia (Score:4, Informative)
There is a perfect location, potentially generating 5000 MW [electricalline.com] (Sorry for the pdf) on the Minas Basin of the Bay of Fundy between Cape Split and Parsbarro. These are the highest tides in the world, up to 16 metres.The entrance to the basin is approximately 8km wide, and could be dammed relatively easily.
On flows [valleyweb.com] "The currents exceed 8 knots (4m/s), and the flow in the deep, 5 km-wide channel on the north side of Cape Split equals the combined flow of all the streams and rivers of Earth (about 4 cubic kilometres per hour)."
Back to where I started, Environmental impact: There would be huge disruptions to the intertidal zone, where much of the life of the bay lives. Siltation would be a major problem. The Petticodiac river in Moncton, NB, was partly dammed by a causeway in the early 1960's. Since then, the river downstream from the causeway has filled in with mud as it no longer gets flushed twice a day, and no longer gets the full effect of the spring runoff. Many of the rivers running into the Bay of Fundy are muddy. Will that settle into the basin? There are no longer any Salmon going up the Petticodiac river, largely due to the causeway. What effect would a huge dam/causeway have?
Any power generation will have environmental effects. It comes down to a choice as to which effects we choose to live with.
Michael (working at a nuke plant on the other side of the bay)
fish power (Score:5, Funny)
Harm? don't think about that, just think how much extra energy is generated when fishies slam into the fan blades that drive the turbine.
Dams don't change world water levels. (Score:5, Informative)
Um, no.
The tide is actually a huge double-lobed bulge around the whole planet. To grossly simplify, two quarters of the planet have higher than normal water levels, and the other two have lower than normal.
Even if you built dams around all continents, the amount of water you'd trap would be about 0.1% of the surface area of the ocean, for a sea level change of one thousandth the height of the _dam_ (not the ocean). This is truly miniscule.
The real problem with dams is that when you build one, you flood a large region of land behind it. For areas that wouldn't normally be flooded (e.g. with hydroelectric projects), this causes environmental upset, and leaches all sorts of crud out of the rocks and soil far faster than rain leaching would (so you get a large spike in, say, mercury levels for a few years). This is unpopular.
Tidal areas are already flooded regularly, so the effects are far less drastic there. All you end up doing is making it very difficult for marine creatures to reach the shore (bad if you built in something like a turtle breeding ground), and change with the timing of the tide cycle (you need to drain the dam when the ocean is near the low mark and fill it when it's near the high mark to generate power, meaning a much more abrubt change in water level for the beach).
Re:Dams don't change world water levels. (Score:3, Interesting)
0.1% of the surface area of the ocean is still huge area, probably far more than you could reasonably build a dam to contain. With respect to the volume of the ocean and dam would be the proverbian "drop".
Re:Environmental concerns (Score:2, Informative)
Re:Environmental concerns (Score:3, Interesting)
If they were to dam it before Saint John harbour (you'd have a hard time driving ships through a dam), the Bay of Fundy is 65 km across. That'd be one hell of a mega-project. It would make the Confederation Bridge look like a plastic model.
It has the largest tides in the world.
And the Saint John River is one of two in the world that reverses its flow every day.
why not miniaturize this technology (Score:5, Funny)
Re:why not miniaturize this technology (Score:2, Funny)
That's a shitty idea
Re:Environmental concerns (Score:2, Interesting)
Re:Environmental concerns (Score:5, Interesting)
But that doesn't mean they can't swim through them and get sliced up instead, does it?
I think you're confusing low head water turbines with aircraft engines. The turbine will probably be something like a Kaplan [waterwheelfactory.com] which has big wide blades and turns at quite low speeds. Fish tend to flow straight through (though it would be rather disorienting for them I'm sure)
What surprises me is that these things have been used for years - I'm sure I read about 5 or 6 different designs of tidal and wave based generators a good 10 years ago when I was interested in these things.
Disclaimer - I have a lot more experience with high speed/high head impulse turbines (my father still has an original 1896 pelton water wheel with 'patent pending' on its cast iron sides - we took it out of production about 6 years ago when we decided the bearings were going through too much oil, and the new peltons could get an extra 20% efficiency, especially with specially wound low-speed alternators rather than old DC motors and v-belts)
I'd like to see some of the more imaginative wave-power systems used though (think balloon on surface anchored to cable on seafloor with bi-directional pump and bigass spring)
Re:Environmental concerns (Score:5, Informative)
Re:Environmental concerns (Score:2)
My biggest concern is that we would be leaching even more energy from the orbit of the moon around the earth. Tidal friction is already slowing the moon down, and by increasing tidal friction, we're accelerating the collapse of the system...
This is dangerous stuff, people!
Re:Environmental concerns (Score:2)
The proposal discussed does not involve a dam so should be easier to construct, however some fish may be upset though.
Re:Environmental concerns (Score:3, Insightful)
Trust me, they don't care. (Score:3, Interesting)
Not that I'm usually a tree-hugger, but it strikes me as hypocritical that the Scandinavians come across as looking good for pursuing "alternative" energy, when in fact that pursuit is motivated by profit margin and a scarcity of fossil fuel.
Re:Trust me, they don't care. (Score:3, Interesting)
Yes, Norway really wants lower oil prices so they can spend less on all that fossil fuel imported there. Oh wait, Norway exported 34.62 million tons [www.ssb.no] of crude oil just in the second quarter of 2002.
One problem (Score:5, Funny)
Oh sure...all those ships running into the turbines will give it extra spin. Free power, hoozah!
Not gonna happen, tell ya why... (Score:2, Insightful)
All right, irregardless of the fact that placing a turbine under the Golden Gate bridge would be a hazard to shipping, it would give off enough power to, what, light up Pier 39? BFD.
If you take a look at the article, it says:
<I>The biggest tidal power plant in the world is a barrage across the La Rance river in northern France, in place since the 1960s. It has a 240-megawatt capacity, but Electricite de France has no plans to build new ones.
Canada's Bay of Fundy in Nova Scotia has the highest tides in the world, at about 39 feet. Nova Scotia Power's 20 megawatt plant at Annapolis Royal, built in 1984, is the only one in North America, but the company is now focusing more on wind. "There are ecological objections to building more tidal plants along the coast," said Margaret Murphy, spokeswoman for Nova Scotia Power. </I>
What does that tell you? That this new station is bigger than France's entry by !60! Megawatts. And that where the biggest tides are, they decided to go into windpower instead. Why? Let me repeat:
<I>"There are ecological objections to building more tidal plants along the coast," </I>
Before you go wishful thinking, read the article.
Re:One problem (Score:2)
The current here can be pretty mean. Rumour has it that some yachts have sailed down hill going out the gate. too much water in the bay trying to leave. I've spent one unplanned after noon out the gate due to sailing backwards out.
But let's be real no one in their right mind is going to put a tidal generator in 300ft of water. Servicing would be a dangerous job. the current would ensure only a few hours a day available to work. Shove it up north in some of those tidal races were tides go up and down 20ft.
Nice but (Score:3, Offtopic)
Tidal power will no doubt make sense in some areas, esp. where political or cultural factors make the increased costs (over fossil or nuclear) palatable & the local coastal conditions are right.
But it seems a better long term solution would be to combine the money and the political will into orbital solar, which has the potential to be cheaper than fossil, cleaner than tidal/wind/ground based solar, etc., and reach just about everywhere on the planet with the same basic technology.
Re:Nice but (Score:2, Interesting)
Re:Nice but (Score:3, Interesting)
Yeah, but that was a computer game... (Score:4, Interesting)
But the proposals for satellite solar power involve wide, low power beams, not enough per square meter to cause a fire or even burn the skin.
The beam, with many times the energy per square meter than unamplified sunlight, hits a large photovoltaic receiver.
Hanging out under the beam would not be good for you, but it would not be instantly fatal, either, and as another poster pointed out, a simple fix would be to turn off the transmitter if the ground station was not receiving the beam.
One can point out greater dangers involved in hangliding around windmills or diving near tidal generators: the best rule is 'don't do that' (or as Ogg said to Mog: fire is hurts!), but like the others, & unlike nuclear & fossil, no toxic exhaust or poisonous waste is made.
As far as a rogue power taking over a beam station, simply staying indoors would be a decent protection until anti-satellite weapons took out the very large target.
More: The World Needs Energy from Space [space.com]
Re:Nice but (Score:5, Interesting)
Ever played sim city 2000? Ever built a microwave power station? Ever had the beam slice through your airport and into a commericial zone?
OK, a little extreme. In reality the beam would be no more powerful then a cell phone.
I have read that Japan plans to launch one [spacedaily.com] in the next 40 years. It will be capable of producing 1GW (although the article says 1GW per second
In 40 years? Who knows.
Re:Nice but (Score:2, Informative)
A better strat for that is to pre-design the landscape so the outer edge of the entire map is a 1 tile wide waterfall, then build hydroelectric power on it. You can increment in small doses ($400/unit if I reall) and they never expire over time!
Fusion reactors should be our goal! (Score:3, Interesting)
Funding for nuclear fusion is scarce, probably due to energy companies' opposition to anything that could possibly mean free energy. Creating a miniature star with potentially unlimited power -- it can generate as much power as it is fed water to spin turbines -- doesn't sound good to the multi-trillion dollar oil, gas, and coal cartels.
The process for creating a fusion reactor has been mapped out since the 1970s -- however, it would require the equivalent of 7 fission reactors to start the reaction before it can sustain itself, and materials including a very large 3-foot thick shield of lithium.
Nuclear fusion could still be done more easily and cheaper than space-based energy projects.
Fusion is good, but not magic. (Score:5, Informative)
Funding for nuclear fusion is scarce, probably due to energy companies' opposition to anything that could possibly mean free energy.
Actually, this is wrong on pretty much all counts.
Fusion reactors are very big, and very expensive. This is why funding for fusion projects tends to get cut when economic belts are tightened. This is also why fusion energy will never be free - your plant has yearly costs (maintenance, and the amortized cost of building the plant over a reasonable payback window). These costs are passed directly on to the consumer, in the form of a nonzero price for electricity. The same happens with things like hydroelectric and fission power - the cost of the fuel required is low (or zero, for hydroelectric). You're paying for the plant/dam.
Lastly, the fact that electricity never will be free (due to the cost of facilities for producing/distributing it) means that a) there will be no magic free-energy solution, and b) our lust for energy had damned well *better* be sated, because otherwise we'll be awfully disappointed when we find out there isn't a free (beer) supply.
Oh, and if anything, I'd expect the big fossil fuel companies to be the strongest _supporters_ of alternative power sources. They're on top of the market now, and as soon as fossil fuel supplies wane and prices go up (or taxes on fossil fuel emissions rise), they'll want to be right there ready to sell the alternatives.
The process for creating a fusion reactor has been mapped out since the 1970s -- however, it would require the equivalent of 7 fission reactors to start the reaction before it can sustain itself, and materials including a very large 3-foot thick shield of lithium.
Startup power isn't really an issue. The real problem is that producing fusion isn't as simple as building a big donut and watching it go. Fusion ignition is harder than anyone thought 30 years ago, and the engineering problems involved with building a useful fusion reactor are orders of magnitude harder that we'd thought as well. Progress is (slowly) being made, but it's going to be a while, and it's *not* going to be cheap.
In summary, I'd suggest doing a bit more reading about fusion and power generation in general before extolling it's virtues as a cure-all.
Re:Ever heard of google? (Score:2)
The other main issue with tokamaks are their sheer size - the research ones are pretty damn big - but from what I have seen, the size requirements for one to power a city was to have been about the size of a large 50,000 seat stadium. I am not saying such a machine can't be built, but the capital costs to do so are pretty prohibitive...
Plasma turbulence. (Score:3, Interesting)
I've heard varying stories as to what the limiting problems are with current reactors (and all are probably true). However, an interesting development re. turbulence was made relatively recently. A group installed sensors and correction magnets on a tokamak, and suppressed the small irregularities in the containment field that turbulence produced. The result was much better confinement.
I don't have a link handy, but it might even have been on Slashdot many months ago.
My personal suspicion is that better materials will provide a big boost. I'm drooling over what nanotubes will do for anything that involves strong magnetic fields - they're the next best thing to superconducting, and their tensile strength means you can run an extremely strong magnet without worrying about it tearing itself apart. Both high density and long confinement times are much easier to achieve with a stronger magnetic field.
Beams are a concern, and lifetime. (Score:5, Interesting)
While solar energy is a very promising option, there are a couple of catches that make it less ideal than advertised:
If your beam intensity is less than, say, the average intensity of sunlight, you might as well build photovoltaics or a solar heat engine on the ground, and save the cost of a satellite and receiving station. If your beam intensity is large enough to be useful (many times the intensity of sunlight), then it will cook birds that fly through it, muck royally with local weather (maybe even to the point of starting a local hurricane), and so forth. While these drawbacks aren't catastrophic, they have to be planned for.
There is no danger of the beam wandering and frying the landscape. It's generated by a host of phase-locked emitters - synced to a transmitter in the middle of the receiving patch. No transmitter to sync to, and the emitters on random phases send energy in all directions, and most of it would have a hard time hitting *earth*, much less your backyard.
Not horribly short, but you're going to have to amortize the cost of the satellite over a decade or two before something wears out or micrometeorites turn your panels/mirrors into confetti. A solar power satellite costs a _lot_ to lift, and power is cheap. My own back-of-the-envelope calculations suggest it costing 10 times more to lift than would be generated from electricity sales over a decade even with very favourable assumptions (100 W wall-plug output per kg of satellite, $10,000/kg to build _and_ launch, $0.10/kw*hr sale price of the electricity).
In summary, solar power will need several technological breakthroughs (or an order of magnitude increase in terrestrial power cost) before being competitive.
The breakthroughs are on the horizon, though. High-efficiency photovoltaic cells are coming on to the market, and thin-film cells can already be bought over the counter. Combine this with aluminized mylar concentrating mirrors, and you might have a satellite cheap enough to lift.
My money's still on fusion, though.
Waterfalls? (Score:3, Funny)
Re:Oh My God - You're an asshat (Score:2)
You're both incorrect.
The gravitational pull of the earth is the source of power.
The water generating the power travels niether through the river nor over the falls. The water is pulled by gravity through pipes called penstocks to the turbines.
Take the next step (Score:2)
The source of power is the dispersal of coalesced energy. The Sun has a lot of it (most of it having coalesced so far as to become matter), so its chemical process is designed to disperse it quickly. This leads to the processes you describe, as our planet has been infected by this energy from the sun.
As if we didn't have things like "properties of matter" to overcome in our quest to disperse energy - we also have to deal with the stuff from the sun.
Obviously this technique is just another one to add to the list of things that aid us in our work - the work that humans are uniquely qualified to do and which sets us higher than all of the rest of the creatures on earth: waste energy.
Now if you'll excuse me, I somebody just turned off one of the lights in the house, so I gotta go turn it back on. Plus, either the air conditioner or the heater just shut off; I need to go figure out which and get that up and running again.
Re:Waterfalls? (Score:2, Funny)
You mean they couldn't build a piece of string?
Currents (Score:2, Insightful)
the oceans that affects the currents? E.g. Mess with the Gulf stream, and Scandinavia will get a
rather cold climate.
Re:Currents (Score:2)
Re:Currents (Score:2)
Re:Currents (Score:2)
Re:Currents (Score:4, Funny)
Err, dude, if you think scandanavia's not cold, I dont want to know where you live!
Re:Currents (Score:2)
Re:Currents (Score:2, Insightful)
I live in England, thanks to your stream we dont get snow, but we dont get much sun either. Also it constantly rains. Please change this so I can buy a sledge.
Re:Currents (Score:2)
I don't know the exact location of these underwater turbines, but here's a page with an illustration of the turbines [sintef.no].
I guess these turbines could be used for normal currents as well as for the intended tidal currents.
How about... (Score:2, Funny)
What a waste this is. (Score:5, Funny)
Re:What a waste this is. (Score:2)
The problem with all these stupid "environmentally friendly" power sources is that the wild-eyed dreamers pushing them aren't being mindful of scale. Wind, solar, and tidal power are all "dilute" energy sources, as compared to hydro, coal, gas, oil, and nuclear which are "concentrated". Windmills seem like a great idea for "free and clean" power until you do the math and realize that you have to litter the countryside with the hideous things in order to generate any decent quantity of power. Solar? Litter the countryside with lovely photovoltaic cells. Tidal? Clog up every bay, fjord, and inlet with turbines. Even then, the grid would need hefty supplements from more reliable (concentrated) generating methods in order to meet demand. So you could have that, or you could spend the money on a nice, clean burning natural gas generating plant right off the bat.
Don't you watch Star Trek? (Score:5, Funny)
Great! Admiral Kirk and crew grab two whales (and baby) to save the planet, they release them .. and the whales get chewed to sushi by the turbines. Probe shakes planet to bits shouting "Hello whales, wakey-wakey!" Ferengi sell souvenir Earth rocks. Profit!
But seriously, there's a lot of power in tides. Nice to see someone actually trying it out.
Millenium Project Up an Running (Score:5, Informative)
Check out information on the Millenial Project here [asi.org] or here [oceania.org].
This also brings me to the interesting Free State project, mentioned on Libertarian Candidate Rachel Mill's Homepage [rachelmills.com] which links to The Free State Project [freestateproject.org]. Interestingly, Rachel Mills decided to raise money for her run for office by selling pushup calendars of the female Libertarian candidates [rachelmills.com]. Yep, Libertarians stand up for your rights and (some of them) do it while looking good too. A much better way to raise money than what the corrupt Democrats and Republicans do, which is by accepting tacit bribes from special interest groups.
Re:Millenium Project Up an Running (Score:2)
How is this on-topic by the way?
Re:Millenium Project Up an Running (Score:2)
I didn't find the catalogue a turn off. I thought it was great, I thought (most) of the women looked sexy and sophisticated. If I were in a state where one of them was running, I would have voted for them. Btw, they're not targetting the average pervert who jerks off to smut porn. They're targetting the type of (more intelligent, more sophisticated) people who will be interested in politics. Thus, classy is good.
Re:Millenium Project Up an Running (Score:2)
I wish they had formatted their webpage a little cleaner though...
Yehaw tidal harness! (Score:5, Funny)
The thermal borehole is the one I'd really like to see in action, though. 6 energy and 6 minerals is a lot, and could really cut down on our dependency on oil.
Err, yeah...
Re:Yehaw tidal harness! (Score:2)
It's Sid Meier's Alpha Centauri. It's part of the Civilization family of games. It's available for Windows and Linux, though the Linux port was done by the now bankrupt Loki Games [lokigames.com] which means locating a copy may prove difficult.
Tidal Power Finally? (Score:5, Interesting)
Here's one web page [horizon.ab.ca] on the subject.
Anyway the tidal power finally line is a bit inappropriate.
Re:Tidal Power Finally? (Score:2, Informative)
"There are currently two commercial scale barrages in operation around the world: a 240 MW bulb turbine at La Rance, Brittany, France and a 16 MW plant at Annapolis Royal, Nova Scotia, Canada. Several other tidal power stations are being considered, including the Severn project in England"
Re:Tidal Power Finally? (Score:3, Interesting)
Derby Hydro Power are constructing a 48 MW tidal power station near Derby to supply electricity to Derby, Broome, Fitzroy Crossing and the Western Metals lead and zinc mine at Pillara. The project will take advantage of the flow from a high tidal range of around 10 metres. The double basin design allows continuous electricity output from the flow of water between the high and low basins which the barrages maintain in two adjacent creeks.
Of course.. (Score:2)
3kW? (Score:2)
Solar, wind, tidal, etc (Score:3, Insightful)
Either way, what seems a bit ironic about how these energies are collected is how inefficient the collection process actually is. In fact how inefficient we deliberately aim to make it. We use such a small part of an enormous source of energy that it has virtually no affect on the environment. No one every argues that solar panels are going to take up all the sun's warmth and freeze our planet. Squeezing every ounce of energy sources has been the pitfall of almost all previous endeavours. Dams destroy river ecosystems. Coal and oil pollute beyond comprehension.
PS. I'd still rather have nuclear power than oil power.
News? (Score:5, Insightful)
Nothing earth shattering that I can see.
Angular momentum (Score:5, Funny)
2. Days lengthen.
3. Everyone has to work 15 hour shifts (8 in France)
4. ???
5. Profit!
Re:Angular momentum (Score:2, Interesting)
Since the moon is slowly drifting away from the earth (again, to the best of my knowledge), we could take just enough energy from the moon to keep it from drifting away at all.
Tidal Energy vs. Wave Energy (Score:4, Informative)
Systems that extract power from wave energy as opposed to tidal energy may be a little less problematic and a lot cheaper to build, albeit also on a smaller scale. The basic idea is to find a waterfront cliff and drill a hole straight down to about 10 feet below the water level, then turn and drill until you encounter ocean. The result is a tunnel with a column of water in it that moves up and down a dozen times a minute or, pushing a fair amount of water and air. Put a turbine in that tunnel in either medium, and you've got power.
Here [umich.edu] is a diagram of such a design that uses a prefabricated tunnel rather than drilling. Google will turn up quite a bit about various designs and research.
All crackpots of course. Every good SUV-drivin' Amer'kin knows thar ain't no energy sources other than oil!
Re:Tidal Energy vs. Wave Energy (Score:2)
Small can be good (Score:5, Insightful)
I have this notion in the back of my head of new homes, and many older homes, being upgraded to include some small form of power generation - a solar array, or more likely a small wind turbine, to supply at least a bit of the home's own needs. Since you can still have a grid power system, homes can supplement each other, cutting part of the grid wouldn't necessarily cut all the power.
The expense would be horrid until these devices became more common, and energy companies could make up for losses in pure energy sales by providing maintanence and installation packages - that is, if you're the kind of capitalist that looks for these kind of opportunities.
Think of it as having a network where, instead of one big central server trying to handle everyone's programs and data, each host can handle most of its own data and processing, and the server's just there for the things that the hosts can't handle on their own:)
Opinions and nitpicks about this greatly appreciated...
Distributed power (Score:3, Informative)
Re:Small can be good (Score:3, Insightful)
That's not much. Doesn't speak well for tidal power in general, as the tidal currents noted of nearly 2 m/s are strong. There aren't that many places in the world with tidal currents like that; while it's strong in the bay area, a typical beach has no current from the tide.
With each power plant only providing energy for about 1000 people, it won't scale well. The article notes it will cost $100 million (US). That's about $100k/home. You can build a pretty kick-ass solar array for $100k, probably enough to power everyone on your suburban street, not just one home.
I agree in principle with what you're saying about distributed power, but these turbines aren't as distributable as other solutions and are too expensive for the small power they generate even from energetic tidal currents.
Maybe it's just me... (Score:3, Insightful)
The article mentions four or five better ways to generate power but this is how they're going to do it dammit!
Look, I'm all for green power. I like the idea, but it seems to me that the whole thing is in the shitter to start with. The conditions that make it good for power generation make it bad for maintenance. It's possibly the most expensive to implement with little to no extra gain over wind or solar. Where's the payoff?
In short, how is this better than umpteen other green power generation implementations with less start up costs, lower maintenance costs and fewer headaches?
Think TCO (Score:4, Insightful)
OK. Now the moaning. The big problem is that people are always thinking in terms of "free" energy at the time of the electricity generation, instead of the Total Cost of Ownership, which includes the construction of the thing. Others have pointed this out, but I wanted to focus on the fallacy of romanticizing electricity generation with free fuel.
The second thing is that with this, the bulk of whatever environmental damage occurs will be largely invisible. Still it might be very limited.
Again, let me say that I am not against this project. I hope that this sort of thing leads to better technologies that are eco{nomically,logically} rational. We shouldn't expect a new thing to reach that at such an early trial. But again, I wish that people wouldn't romantize electricy generation based on "free" fuel sources.
Re:Think TCO (Score:4, Insightful)
The article on this tidal current generator is very upfront about the costs of the project - so they are not really saying it is 'free'.
Your concern about romanticising 'free' energy is a terminology issue. No serious renewable energy proponent would say renewable energy is 'free', (because typically most renewable energy technologies have high up front costs), but rather that by definition the energy _source_ is 'free' - ie renewable.
The tidal example in this story is a prototype designed to use tidal power without having to construct a large dam (as per existing larger projects). The design goal seems to be: 'extract the energy from tidal currents without large earthworks so as to minimise the impact on sea life, and make it reliable and maintainable'. This design goal is what makes it new.
If the UAT works out for this prototype then the next generation would have a much lower up front cost (less research cost, economy of scale etc) so the TCO would drop from the current $'s per kwh to hopefully a few cents per kwh. Even if it ends up being more expensive than other existing technologies (eg offshore wind) it may be applicable to some areas which have low wind resources or other limitation. (Variety is good, monlithic/monoculture is bad)
Development of coal/oil/nuclear technologies went through similar improvements as they matured - helped along by large taxpayer subsidies - degrees of magnitude larger than any subsidies currently given to renewable energy R&D.
Some rough price comparisons:
TCO for wind generation is $0.03-$0.05 / kwh
the price for coal without TCO is $0.04-$0.05 / kwh
TCO for coal which includes costs of global warming, health damage, acid rain, site cleanup, centralised infrastructure etc could make that $0.1 - $0.2 / kwh
TCO for nuclear fission - depends on the time frame for cleanup and the number of accidents (the cynic in me says ask the people who live near Chernobyl)
The modern era requires energy sources that are tailored to the loads and situations where they are required. One solution/size does not fit all. There needs to be a mix of renewable and non renewable energy sources with an real public commitment to make the gradual but significant transition away from fossil fuels. There also needs to be public commitment to use energy more efficiently - good efficient design in every building, vehicle and appliance counts. As the price of oil grows exponentially in the next 50 years there will be plenty of incentive to move this way.
Power generation is always discussed in TCO... (Score:3, Informative)
Economics (Score:4, Informative)
Re:Economics (Score:2)
According to the article, this doesn't have much enviromental impact, sure as hell it is nice to have all those ugly windmills hidden from view and birds.
J.
Re:Economics (Score:2)
Holy Shit! That's about 10 times what I pay. I wonder if it's mainly because of currency differences, climate (Canada vs Missouri), size of home and family, or the recent "jump" that you mentioned.
Anyway, the calculation is a little different for me.
TIDE POWER (Score:2, Funny)
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Sure... until we get CRUSHED BY THE MOON! (Score:5, Funny)
But, doesn't conservation of energy suggest that "we can't get something for nothing"?
By taking power away from the moon's orbit, aren't we just accelerating the decay of that orbit?
Sure, we've got the power now, but what good will it be when the moon comes crashing down to KILL US ALL!
*runs and hides*
Dangerous! (Score:4, Funny)
They are taking power from the tides? The tides are generated from the gravitational pull of the moon. Taking power from it reduces the orbit of the moon, inevitably making it crash into the earth. Doom Doom Panic Panic.
I wonder how many exawatt-years that would be until it gets that far though...
Not entirely environmental (Score:2, Interesting)
When my aunt was in college they went just west of here into Minnesota to check out the environmental impact of a large windmill farm (interesting stuff, sitting in Minnesota, controlled in California, owned by Enron in Texas). There were large numbers of bats running into the blades. I dont remember what they did to curb this, although I think it involved increasing the rotational speed. Any way, bet the same effect will happen with these.
Bet thatll teach Flipper not to hang out near the shore.
It's tidal current! (Score:2)
The turbine is driven by a water current, not a tide, so it's not "tidal power". Yes, the current is driven by the tide but it's still a current (the article calls it a "tidal current"). Tides are the vertical movement of water, current is the horizontal movement of water. I just thought you all might appreciate this chance to expand your nautical knowledge. :)
My tide and current book for San Francisco Bay says the average peak tide at the gate is about 4.5 knots, which if I did my math right is about 7.6 feet per second, a little less than the one in Oslo.
I think though that Norway has many fjords, which are rather long, where they can line up a lot of thise turbines one after the other. Whereas the 'Gate is a just a relatively short constriction. They plan to build 20 of these things in Oslo just to generate enough power for about 1000 homes. I don't think there's 20 good places for a turbine like this in the Bay, so I'm not sure it would be very practical for us. Dunno, but that's my idle speculation for the day. :)
very, very old news (Score:2, Informative)
It's the "Usine Maremotrice de la Rance" (tidal generator of the Rance river) near Saint-Malo in Brittany.
It has been in service for 36 years and is still the only industrial-scale tidal energy generator in the world. It is also the most visited industrial site in France (300,000 tourists annualy).
More info at http://membres.lycos.fr/larance/main1.html
RTFA! (Score:2)
J.
Why don't we... (Score:2)
Say you had two massive, extremely sturdy poles which were joined together with a hinge. Let's say the hing was really a generator, and that this generator had an extreme gear ratio such that it would take thousands of tonnes to move opposite ends of the poles closer together. You just wedge the poles into something really strong like a tide or a fault line, etc...
Could we not gain a lot of energy from this technique?
Tidal power is NOT a renewable resource (Score:3, Interesting)
Remember the tho main effects (in the VERY long run, of course, though they can be measured right now by atomic clocks) of tidal power plants
1. They slow the earth rotation (which is quite normal, since they oppose the movement of tides, therefore making the earth slightly more "coupled" to the moon). No kidding.
2. They move the moon slightly away from the earth (slowly, but every year) for the same reason. You can also deduce that by another way, which is the conservation of momentum in the couple earth-moon.
Those issues were raised in their time when France built its tidal power plan on La Rance, near the town of Saint-Malo. A lot of people said that "the consecutive slowdown of the earth could never be measured". It has been. And, of course, nothing will revert if the power plant is - or rather when it will be - later stopped.
This is of course not a concern for us, but over the course of mankind as a species, it is. It is clear that just for energetic reasons there is no reasonable hope for the whole 6 billion people of mankind to emigrate anywhere else, even if we had an idea of where that "anywhere else" could be. So let us be careful with these experiments.
I wonder if the La Rance power plant could be in the future bombed by a decision of the UN or the NATO, just because it represents a (very very very very very) long term ecological menace
The Hunt For Red October (Score:2, Interesting)
This idea wouldn't be all unlike the underwater "jet engine" that the Red October had....
Saint-Michel (Score:4, Informative)
Some readers might not know that there is a successfully working tidal power facility in the Bay of Saint-Michel in France since 1966. Its output is 240MW [iclei.org].
I found some pictures [raubacapeu.net] on the web.
The most stable source of energy. (Score:3, Interesting)
Oil, coal, gas and uranium are in limited volumes at the sources we find them, and will be gone when those sources are used up.
Where it is windy today might turn into barely a breeze over years or decades depending on weather pattern changes.
The sunny place you put a solar panel today could change to mostly cloudy all year in a few years to decades also.
Only the tide is immune from all near term natural and man made changes (short of intentionally blocking waterways just to screw with the location of a tidal power plant).
If they can figure out ways to make this economical, it will be a much more stable energy source than all other earth based sources combined.
One other thing to consider is that the one constant bottleneck in all of these forms of energy (except for direct solar, not "boiling water" solar) is the turbine. Increase the efficiency of turbines and you can get more energy out of all the current power plants by doing retrofits. It seems like this should be the highest priority in energy research.
Problems with all methods of power generation (Score:3, Funny)
--Coal/Oil/Natural Gas: Air pollution
--Nuclear: Nuclear waste
--Hydroelectric: Rivers need to be dammed
--Geothermal: Releases lots of sulfer and arsnic
--Solar: Not cost effective
--Wind turbines: Kills birds
--Tidal: We'll think of something
a 1.1MW/150kW wave energey plant ... (Score:3, Interesting)
Old, old news (Score:4, Informative)
Using tidal power for mechanical energy has been around for centuries. Here in Boston we have three meter tides; at the time of the revolutionary war we had mills driven by impounding tidal water in the Back Bay. Eventually the bay became so noxious with sanitary and industrial wastes that it was landfilled to make the neighboerhood of the same name, which is the only part of Boston with streets in a regular grid layout.
Boston and the Bay of Fundy are part of a the same physical oceanographic system where the amplitude of tides are increased by resonance. There are similar places in southwest England and in Scandanavia with large tidal amplitudes. I'm sure that many places with a tidal amplitude of two or three meters or more have a history of tidal mills.
Norway? (Score:3, Funny)
They'll probably call this the "Slatibartfast tax".
Re:The Power Source (Score:2)
Re:The Power Source (Score:5, Informative)
Friction between the Earth and water, drags the tidal bulge a little bit ahead of the moon. This, in turn, cuases an unbalanced pull that slows the Earth's rotation and transfers angular momemtum to the Moon.
The result is that the moon moves about 3.8cm further form the Earth every year and the Earth's Day increases by about 1.5 ms per century.
Tidal power plants would increase this drag and slighty speed up this process, (very, very very slightly, not enough to make much of a noticealbe difference, but a difference none the same.)
In effect, tidal power plants derive their energy from the difference between the Earth's period of rotation and the Moon's orbital period. Pulling extra energy from this system slighty hastens the day when the Earth eternally shows only one face to the Moon.(Not enough to worry about, though)
it really does seem that recently (Score:2)
-- james
Re:But what happens... (Score:2)