Tidal Turbines

Hi,

Congratulations.

Tides are not consistent in nature, so my questions is how do they maintain the frequency and voltage at required levels?

10 Megawatts 100% of the time or at peak ebb and flood, and then zero at slack water?

It's more or less free...eventually.

MY EYE! Absolutely, nothing is free. All I ask is none of my money pays for it and it doesn't happen anywhere near where I have the right to care about.

If they work, put them in rivers--Rivers don't waste time changing direction.

Let's put car treadmills at stop lights--The cars could turn generators for a set time before we let them go--FREE POWER, YEAH!

Sorry about the sarcasim--Couldn't help myself.

In what sense are tides "not consistent"? Tides are one of the only things in science that can be accurately predicted without the necessity of understanding their mechanism. That gives them the advantage over wind or even wave power, which are less predictable (and more likely to be intermittent).

I don't claim that wind or waves are reliable either. If tidal power works--do it in a river where the current is constant.

or 110,000 tons of coal ?

No, just oil or gas.

The power is hardly free. There is a huge capital investment and it produces power according to the tides, not according to demand. And it has taken another piece of what we are slowly coming to realize, which is our coastal waterways. This piece of the ocean is now more difficult to navigate and more difficult to fish. And it has probably made life more difficult for some marine organism, whether by blocking it's migratory path, shading it's habitat or bonking it on the head as it flexes.

Agree. Why is it they don't tell us the cost of installation, estimated lifetime, maintenance costs? Maybe because it's a huge waste of money? Now, on one hand, if this were designed to be an experiment to accurately judge the costs vs. benefits I can accept an investment loss on a small scale before embarking on much larger projects.

Anyone want to wager that the taxpayer is funding this?

I predict, that like many wind turbine programs, the costs will far outweigh the return because of overly optimistic reliability predictions. I still remember driving east of San Francisco through the very windy Altamont Pass area peppered with hundreds of wind turbines, and only a handful were spinning, the rest were idled due to maintenance issues. What a feel-good colossal waste of money. Perhaps updated technologies and better understanding of the design issues will make a wind turbine that you can set it and forget it.

Unless I misread every damn thing in all the linked articles, each turbine will supply electrical power sufficient to supply 26 and a fraction houses. Is this for real? What ever happened to economy of scale? No figures were given regarding costs, durability, maintenance... This looks like a boondoggle in the works.

Now imagine these generators running motors pumping water back up stream for hydrower at dams.

Or installed in the spillways of small dams all along rivers.

Small coffer dams could be build every 300 yards along a river and have 4 or 5 these running.

Only to be spilled in dam draw downs for the sake of fish.

It is really quite scary that someone would try to effect the tide(anywhere) for such a puny potential of sporadic power.

I will argue this---WE COULD REMODEL ONE DAM ON THE COLUMBIA RIVER AND RECOVER AT LEAST 1000 MEGAWATTS! The remodel would not hardly affect a thing from what we have now.

Tides?--Come on!

Not sure but houses typical of Texas (by Goshen) and of NYC are quite different in terms of occupancy.

Economy of scale? Perhaps the East River installation is primarily a test bed? And a government funded one at that? (Gotta start somewhere before full scale comes into play.)

Something to consider, experimental pilot scale projects can be exempt from NEPA. If you generate electricity for 26 home with one, to be effective you are going to need maybe 100,000. You now have to consider the impacts to the environment, including aesthetics, impacts to fisheries and existing industries, impacts to wildlife (including impacts on the tidal zones), etc.. Once one of these things goes in and the public gets a look at it, you could kill all future projects and get enough public pressure that you end up having to shut down the project.

Hide the projects from the public(tax base that funds this)and force feed them what they are too stupid to want?

Does not matter, all projects have to go through either State or Federal EIR process, unless covered under a Statewide or Federal Agency programmatic EIR with a general permit of some sort. As such part of the process requires a public disclosure and comments period. However, there is nothing that indicates you can not do the bare minimum for public disclosure, and do it obscurely. However, you would get sued if it was too secretive in the disclosure, and the project stopped while you go through the courts. The fastest way is to be as totally open as possible to the various interested parties, and pre-emptively address their major potential concerns that could reasonably incur court intervention in manner that appears to adequately mitigate the environmental risk. You then have forced them to fighting over trivial things, then you fight hand and tooth over the trivial things, and the courts will probably get pissed off at the opponents and throw them out on their head in the first few trials. After a few court losses where the courts find the subject so trivial it is not worth their time from the start of the trials, I have found that many groups immediately drop most other suits rather than incur the trial preparation costs for an instant embarrassing loss. Also, even harder is the administrative reviews by agencies, Fish & Wildlife can be quite a nuissance and rather stupid when it involves even simple engineering.

Well--the rotting corpse of industry that I just left will certainly free up so much power that the need for it is going to ebb away(no pun intended)--So right now if utilities are forced to purchase high priced alternative power, before even hydro electric, with no one wanting to pay for it. It will make recovery from our current problems a lot harder.

Is a river the best place for tidal turbines?

Surely the best place to put them is where the tide is at its strongest - where erosion is taking place.

OK, so that would mean building them stronger and so more expensively, but the benefits of reducing the force of incoming waves, so reducing the effect on sensitive sites may just be worthwhile. We would get electricity and those living near the sea may just be able to keep living there a while longer. I'd rather know these active defences were sitting below the surface, out of view than to see miles upon miles of huge concrete walls sitting like Kris's bath sides at the edge of the oceans.

It fits exactly with the way mankind is going......eliminate the natural changes which occur on this - and no doubt every other - planet.

Hudson R.....................Manhattan ......................................East R..............Roosevelt Isl>>Long Island>>L.I.Sound

(Note boat wake indicating where "river (and wild-life-migratory) navigation" is taking place.)

Not meaning to argue any side, ... I wonder if many of the posts from afar don't misperceive the man-made nature of the submerged coastal inlet (along "East Side Manhattan") called "East River"; and the paramount virtue of harnessing power from it: that of decentralizing (localizing at point of use) energy generation, thereby reducing the costs and losses entailed in power transmission.

Also, if it's anything like some other states (viz., Calif) this project could be in response to state legislated mandates for public reporting of, and meeting statutory targets for readjustment of the power source-allocation mix.

See more?

CowAnon:Also, if it's anything like some other states (viz., Calif) this project could be in response to state legislated mandates for public reporting of, and meeting statutory targets for readjustment of the power source-allocation mix.

That is the exact problem--and really the only one in my opinion. Politicians answering technical questions they don't understand with law.

Day High Tide Height Sunrise Moon Time % Moon
/Low Time Feet Sunset Visible

Su 5 High 1:18 AM 3.9 6:57 AM Rise 1:20 PM 27
5 Low 6:18 AM 1.3 6:31 PM Set 10:07 PM
5 High 1:28 PM 4.6
5 Low 7:33 PM 1.2

Above are the tides for today--5.8' of difference--The times are for slack water(no flow at all)4 a day, and 2 max ebbs(out) and 2 max floods(in).

There just doesn't seem to be enough here to do anything substantial with. It would make more sense to me to put these things in a river--But then we could just dam the river--or better yet, just put them below the dam, if they work.

Alternative energy is the question and we are getting a lot of answers--but not all of them are good. I think we need to start discriminating.

Anyway--I agree with you CowAnon, until it comes to funding it--these power sources need to be viable and should be funded during development only. Tax dollars get spent to put them into production and operate, it creates an enviorment where there is absolutely no incentive to waste time or money improving the ideas.

I'm assuming your tide table is for the King-/Pierce-County boundary adjoining area...and, yes, that location probably has little of offer for tide harnessing...I wonder about the locks at Lake Union?

As to NYC's East River there is also the inlet/bay/sound narrowing aspect which has the effect (in all places) of increasing tidal range. Moreover, there's Hudson River flow, diverting between north Manhattan and Bronx into the East River (river flow that would be accentuated during tidal ebbing after tide-induced river backup is reversed) that might serve to increase East River ebb flow velocity(?)

There is reason in my mind to both agree and disagree with the "politician answering" characterization.

• In Calif and Washington both, politicians do not operate in a vacuum; they (and the state and people) have a substantial number of highly skilled experts to rely on. The politicians' task of mediating between various competing interests (suppliers & consumers, landowners and environment, urban vs rural, coastal vs inland, fishermen vs indigenous...to name a few) while satisfying their own constituents' (perceived) interests is not an enviable, or an easy, one.
• The down side of any government (science based) program is a tendency for it to grow and metastasize into an inertia-bound bureaucracy; a competing interest group in its own right...and too often the source of onerous regulation or interference.

But that is not to say that private commercial interests (such as power generation and distribution (and other utilities) are not also prone to the same effects; and that the progress would be made without the action of government.

Seems to me that the reason government mandates (such as power source allocation, or waste stream realignment) so often rankle, is because the positive results are not readily visible; or become so only over long time spans.

As to discriminating and the NYC tidal project, I have mentioned elsewhere (sorry for not realizing I didn't sign on) that the use of that project as a test bed could be a necessary, and therefore publicly beneficial, means to acquiring "empirical discrimination expertise"—perhaps the only way. But again, test bed benefits are seldom spectacular and seldom seen quickly.

Conwagon--The tide table was pulled from the Brooklyn bridge--there, for today. The tides here run a lot higher.

Your East river looks slightly different than the Puget Sound.

300 tidal turbines sounds like a production, not research. The outfit installing and responsible for them working Pro Bono? $7.3 million-www.energy.gov/news/6554.htm

It's just silly--If this junk worked, why not place them below dams in rivers? The current wouldn't slow or change direction.

After extensive effort this plan offers up to 10MW.

Previous post this thread: WE COULD REMODEL ONE DAM ON THE COLUMBIA RIVER AND RECOVER AT LEAST 1000 MEGAWATTS! The remodel would not hardly affect a thing from what we have now.

FYI, the current would slow downstream as the energy withdrawn from the stream would be a head equivalent lost across the generating system. This must be an effect anywhere you install such energy systems, even tidal energy systems and wave energy systems must extract energy in the form of a head loss across the system. On a small scale this appears insignificant, but there is some scale where it would cause significant adverse environmental impacts to something adapted to that specific kind of habitat, like tidal pools.

Thank You and well put--

Wave energy is argueably more feasable on an enviormental level--BUT, it would coincide with the wind--No wind, no waves and wind still has the grid penetration hurdle--A lot of good another energy source would be, producing power during the same sporadic times.

There are not many areas where the tidal range is sufficient to make power generation feasible.

Bay of Fundy (60'), Kimberley region of Australia (30'+) are probably the 2 that spring to mind.

In most other areas, wave power will be more profitable and consistent.

Like wind power, power output is a function of the area covered by the generators.

Tides are at least consistent. Wave power ranges from zero to storms which have the potential to wreck the generating equipment.

Wave power could well generate a useful supplement to normal methods of power generation, without drastic environmental side effects.