The biggest environmental issue would be if you extracted too much energy, the stream might slow or stop or reverse [there are other factors weakening it already. The Gulf stream moderates the climates of North America and Europe, any loss of that circulation will have huge climate impacts on both continents.
The UK has just signed up for Europe's largest [and possibly the world's largest], tidal stream power station. [similar technology on a more modest scale, just a few gigawatts ]
Tidal streams in some places are much faster and therefore more concentrated sources of energy than ocean currents.
No one has mentioned the obvious....maintaining & servicing these turbines. With wind turbines, one can readily climb up and enter the turbine to perform service to the gearing, etc. How will you do this several hundred feet below the surface? Will you cable them up to perform service? What about transmission line issues (impedance)? These turbines will be placed several miles out to sea, so cable resistance will reduce the voltage...which will mean substations to amplify the voltage so as to get a meaningful amount back to shore. What about electrolysis? Anyone that owns a boat knows what happens to outboards because of electrolysis....are they going to place zincs all over the place? Bottom line...this is a hairball! The cost to benefit ratio is NOT there. If the aim is to employ people...these will be a HUGE success...
The morons around here, Southern California, required So Cal Edison to cool the water before pumping into the ocean as if a little warm water was going to hurt anything. This stopped a multi billion dollar nuclear plant in a place where energy is sorely needed. The EPA and other government organizations have become so powerful and so ecofascist that underwater turbines is little more than a pipe dream IMO, at least until the current crop are voted out.
Cost is prohibitive. Who do you think will pay for this. The cost will be paid by the consumers when they get the bill. Oil companies probably do own it or t least stock and cheap energy is not what the customer gets
The Ocean currents are fierce how long would a turbine
last . A lunchtime or a few years ?
tricky step. lookup into yahoo and bing. it will help!
Mechanically, it is possible. There just is not an investment pool out there and no one is dunning it up.
Ecologically though, what about all of those dolphins that will unwittingly swim into the blades?..../:}
I'll get cold if you stop the flow, better to wean you off using cheap power.
cost. it's still cheaper to burn coal and dump the waste.
Considering that the amount power in the current for only 24 hours is more than all the output of all power stations in the world, I am surprised that something is not there already, like at least a prototype.
I know there are environmental issues to consider but even a fraction of that power can reduce US electricity cost by half at a stroke. Off course the Oil company's wouldn't want that unless they own it themselves but which one? Anyway for that kind of output it is even worth moving the whole marine life to another suitable place and reroute the shipping lanes.
So what is going on? This project seems to have been kicked into the long grass. If it were in Europe, it would be understandable. E.g just laying down a new rail way of 300 miles is to take 25 years and it hasn't even been decided on after ten years of talking.
