Re: [Vo]:Tidal power

2017-10-27 Thread ChemE Stewart
You missed the part where the tens of thousands of fish died the same week
the turbine was put into operation.

http://thechronicleherald.ca/novascotia/1428745-studies-lacking-in-bay-of-fundy-fish-kill-say-fishermen

That particular model is putting a strong magnetic field (1,200,000 nT)
through the open, conductive saltwater gap, between rotor and stator.
Things corrode very quickly when you put a voltage in seawater.  All of
their sacrificial zincs were gone when they pulled the turbine after a few
months.  While it was connected the first 3 months I calculated it only
supplied enough power to the grid to power a few household treadmills.

I guess it is more environmentally friendly to be killed by green energy.



On Fri, Oct 27, 2017 at 10:25 PM, Jed Rothwell 
wrote:

> The potential energy from tides, waves and the Gulf Stream is immense.
> People have known that for a long time. There have been many attempts to
> tap these sources. They have failed because the ocean environment is so
> challenging. Ships and boats require constant maintenance. My father, who
> grew up among them on Long Island and Bermuda, said that a boat is "a hole
> in the water into which you pour money."
>
> The Bay of Fundy is one of the most promising places for tidal generation.
> A large generator was installed there in 2009. It failed *within days*.
> See:
>
> http://www.cbc.ca/news/canada/nova-scotia/tidal-power-bay-
> of-fundy-turbine-electricity-emera-hydro-1.3862227
>
> Think about that. Here we are in the 21st century with computer
> simulations, immense knowledge of engineering, materials and so on, yet
> this machinery failed as quickly as the first transatlantic cable did in
> 1858! Because putting things under the ocean is difficult. H. G. Wells was
> a technophile yet in 1901 he said, "my imagination refuses to see any sort
> of submarine doing anything but suffocate its crew and founder at sea."
>
> I am not saying this technology will never work, but the fact that a
> megawatt-scale installation failed within days is telling. It's telling you
> this is a lot harder than it looks.
>
> Tapping a flow of fresh water in a stream or river is a lot easier. People
> have been doing that for ~2,500 years.
>
>


Re: [Vo]:Tidal power

2017-10-27 Thread Jed Rothwell
The potential energy from tides, waves and the Gulf Stream is immense.
People have known that for a long time. There have been many attempts to
tap these sources. They have failed because the ocean environment is so
challenging. Ships and boats require constant maintenance. My father, who
grew up among them on Long Island and Bermuda, said that a boat is "a hole
in the water into which you pour money."

The Bay of Fundy is one of the most promising places for tidal generation.
A large generator was installed there in 2009. It failed *within days*. See:

http://www.cbc.ca/news/canada/nova-scotia/tidal-power-bay-of-fundy-turbine-electricity-emera-hydro-1.3862227

Think about that. Here we are in the 21st century with computer
simulations, immense knowledge of engineering, materials and so on, yet
this machinery failed as quickly as the first transatlantic cable did in
1858! Because putting things under the ocean is difficult. H. G. Wells was
a technophile yet in 1901 he said, "my imagination refuses to see any sort
of submarine doing anything but suffocate its crew and founder at sea."

I am not saying this technology will never work, but the fact that a
megawatt-scale installation failed within days is telling. It's telling you
this is a lot harder than it looks.

Tapping a flow of fresh water in a stream or river is a lot easier. People
have been doing that for ~2,500 years.


[Vo]:Tidal power

2017-10-27 Thread H LV
​'​
The tide is turning for underwater turbines
​'​


https://horizon-magazine.eu/article/tide-turning-underwater-turbines_en.html

​Harry​