[Devil]

Really! It doesn't take much intelligence to realise that he has fitted a small tank with petrol in it for just that and disconnected the real tank :D

[Guest]

US patent office seemed to accept that it's possible, way back in 1935.

BMW also seem to think this will work

[Guest]

US patent office seemed to accept that it's possible, way back in 1935.

BMW also seem to think this will work

[bentstrider]

I don't know if I got this from a "Popular Science" or Mechanics article.
But I remember reading something up on a viable replacement for monster dams like the Hoover Dam.
These devices are just wind turbines. Except for the fact they could be placed under water.
When under water, the passing water current turns the fan blades.
As long as the river or lake doesn't run dry, you have a power source that could go on for practically forever.
Just put a group of these in a certain area of the river you plan to use.
Place a sort of underwater fence around it to keep wildlife out.
Yet also keep the fence felxible enough for boats to skim right over the top of the field.

[savethehumans]

Right now, the UK is investing in developing wave and tidal power. It is good to get such an infrastructure going NOW...we might not have the energy available to build one later!

The oceans are pretty powerful forces--it'll be interesting to see how the UK's efforts work out...very SOON, I hope!

[duff_beer_dragon]

Again, yeah!
Hydroelectric pumps can be placed in rivers, if you are fortunate enough to live nearby one or have one on your property.
Water mills would work too - remember those amazing looking wooden wheels? I feel lucky to have even seen an actual real one.
Windmills are real too - just like wind turbines except they are directly used to power the millstones for the grain, or other crops.

And there are wave power stations too.
So, another bunch of examples of already-working renewables.
Trees use gravity to get water to travel up from the roots to their tips - I reckon such a system could be used to make a self-contained liquid-fuel wheel system - like the water mill. Probably already has been done.
At the CAT centre in Wales, they have a water-balanced railway

[Optimist]

$this->bbcode_second_pass_quote('', 'T')rees use gravity to get water to travel up from the roots to their tips

[bentstrider]

Perpetual motion has always been around.
People were just to lazy to look into it.
One thing I've always thought about was a water/spoon mechanism.
To get it going, you pour water into one spoon, and the weight....
I would have to draw and scan a picture.

[backstop]

BentStrider - The Run-of-Current Turbine is certainly feasible and has a record of R&D going back at least to the 1970s.
Two main a designs are being advanced, with the UK setting devices off its SW coast to harness strong tidal currents. These follow the original design pholosophy of minimizing structure costs by having free-standing 'vertical axis' turbines set on the sea-bed.
I gather (from New Scientis last year) that a US version ignores that philosophy and aims to build massive underwater concrete fences (off Hawaii ?) with gaps housing turbines, in order the raise the speed of the current flowing past them. Given that sea currents are notoriously dicey to bugger about with, I guess this is probably guilding the lily.

The Torque output from Reading Univ research in the '70s was 1.0HP per m.sq. swept by the turbine on a 3knot current (on the River Thames). Power output changes with the square of the speed of the current, thus a square metre swept in a 6knot current will give 4HP of torque.
The potential of this option is thus very localised as an urban-scale power source - only a few places around the world have sufficient tidal currents to be worth harnessing, but some of those (such as off Nova Scotia) are really massive.
The widespread application of this option is more likely to be its use for water-pumping for irrigation from slow flowing rivers, or for local power from fast steep rivers, for which it has huge potential. One such ran for irrigation for several years on the Nile before being lost in local warfare in the '80s.

With regard to the miasma of a perpetual motion machine, I shouldn't spend too much time hunting them. There are several difficulties commonly overlooked by their devotees.
First, perpetual means continuing longer than the sun, and us, so there's no one to observe and prove it.
Second, its no use at all unless it's providing energy to us, meaning it must either create energy out of nothing, (a nonsense) or transmit energy produced by an external source (and is therefore not perpetual).
Third, even a flywheel sent spinning off into the near-perfect vacuum of space will face steady friction by inter-stellar dust and will, over aeons, slow to a halt, or alternatively just get splatted by a passing asteroid.

I guess the UK govt.'s DTI website will give some news about the RoC turbines now being installed if you'ld like to learn more about them.

[Optimist]

$this->bbcode_second_pass_quote('backstop', 'I') gather (from New Scientis last year) that a US version ignores that philosophy and aims to build massive underwater concrete fences (off Hawaii ?) with gaps housing turbines, in order the raise the speed of the current flowing past them.

[rerere]

$this->bbcode_second_pass_quote('duff_beer_dragon', 'A')gain, yeah!
Trees use gravity to get water to travel up from the roots to their tips - I reckon such a system

[small_steps]

$this->bbcode_second_pass_quote('backstop', 'T')he Torque output from Reading Univ research in the '70s was 1.0HP per m.sq. swept by the turbine on a 3knot current (on the River Thames). Power output changes with the square of the speed of the current, thus a square metre swept in a 6knot current will give 4HP of torque.

[backstop]

Small Steps - you're quite right in what you say. I used the term torque, valued in horsepower, because I didn't want to use the term power which most people associate with electricity.

So the figures I quoted are also quite right, and are quoted in "The Power Guide" a catalogue of energy equipment that I got from the publishers, ITDG (the Intermediate Technology Development Group) back in '78.

They've recently done an updated version if anyone's interested in Googling for them. Well worth getting for all sorts of small to medium energy plant.

regards,

Backstop

[backstop]

Small Steps - I've just re-read both our posts and realize that to be clear I should have said "Energy output changes with the square of the speed of the water current."

However, a 3 knot current with 1.0 sq.m swept by the turbine's foils yielding 1.0HP, used in a nomal genny will give 746 watts (per HP) x (say) 85% efficiency yielding about 634watts output of electricity.

Raising the speed of the water current to 6 knots will give 4 HP of torque, which in turn could yield 4 x 634watts = 2.536kw (with the same genny efficiency).

Sorry for any confusion caused.

Regards,

Backstop

[gg3]

I've heard of successful prototypes a couple of years ago while I was working on the wind project.

At the time, we also realized that it would be possible to use offshore wind turbine foundations as anchoring points for tidal turbines. After all, you already have a massive amount of concrete and steel, and the transmission line capacity, so all you have to do is provide the hardware to anchor the tidal turbines in place. The incremental cost of piggybacking these on offshore wind farms is therefore relatively low.

Some of the locations we were planning for offshore wind sites (in this case on-river) are also well known for strong river currents.

Even in ocean locations where all you have to work with is tidal flow, the low cost of piggybacking water turbines on top of wind infrastructure, is very tempting. The water power, being less subject to spot fluctuation than wind, is also a good source of "firm power" in such an installation, which helps improve the price that an independent power producer (IPP) can get from selling power to the local utility grid.

Re "perpetual," not to keep feeding a digression, but IMHO one doesn't have to worry about theoretical cases of "keeps working literally forever." The simple criterion of running for a more "realistic" length of time is sufficient to disprove the vast majority of cases (I'm always hesitant to use the a-priori "all" or "impossible" because one might someday be proven wrong).

[Graeme]

Hydrogen Technology Applications, Inc. based out of Clearwater, Florida has just invented a new device called the H2O Model 1500 Gas Generator. The gas generator runs off water and produces a unique water/hydrogen gas that can be used for welding metal because of it's extreme heat capabilities. This is just the tip of the iceberg though. They also plan on using this very same process to run automobiles and other devices. That's right, a car that can run off water. Check out their website for more details.

http://hytechapps.com/applications/HHOS.htm

[Eli]

We are saved!

That guy standing next to the water car looks very sharp in his cop shades and members only jacket. I wonder if he is scientify guy? Those guys are real smrt.

[Googolplex]

Looks like another take on the whole "use electrolisys to generate fuel (hydrogen) and store it instead of just charging batteries" idea. Overall, its rather pointless, as it wastes lots of energy. Just a simple charge-and-go electric car sounds like a much better idea, especially if Toshiba's new one minute charge batteries really materialize.

[gnm]

just another take on the "magic" "browns gas" - which is another way of saying nasty ready to blow co-mingled hydrogen and oxygen... you ought to google on browns gas to see the loads of BS attributed to it...

either they are stupid or they think we are.....

-G

[Brandon]

$this->bbcode_second_pass_quote('Googolplex', 'L')ooks like another take on the whole "use electrolisys to generate fuel (hydrogen) and store it instead of just charging batteries" idea. Overall, its rather pointless, as it wastes lots of energy. Just a simple charge-and-go electric car sounds like a much better idea, especially if Toshiba's new one minute charge batteries really materialize.