(Page 2 of 2)
Blades of power: Shown above is one of the turbines for the SeaGen project. It is 16 meters in diameter and produces 600 kilowatts of power. It turns at 14 revolutions per minute.
Marine Current Technologies
SeaGen is a $20 million project, and Fraenkel estimates that any such project right now costs $7 to $8 million per megawatt. "The technology is emerging, so right now it is expensive," says Taylor. "But we expect that as it gets developed at a commercial scale and we learn more about it, it will be at a price consistent with other forms of renewable energy." He says that he expects Nova Scotia Power's one-megawatt plant to be installed in the Bay of Fundy in 2009. It will be operated for a two-year demonstration project. Clean Current Power Systems of Vancouver, Canada also announced plans to build a system that generates two megawatts of power from the tidal currents in the Bay of Fundy in 2009.
MCT has even larger plans. It has teamed up with a German utility company to build a 10.5-megawatt project off the coast of North Wales. Fraenkel says that the company has already started working on the system, which should be developed within three years.
The engineering giant likes the predictability of marine power—which can be "calculated for centuries in advance."
Ten wave and tidal projects will generate 1.2 gigawatts of power.
Perhaps they could contact Whalepower to put some tubercles on those turbine blades.
In the places where depth allows, the inside passage between Vancouver Island and the mainland would be perfect for this. The tide bores with tremendous energy, the Johnstone Straits region for example, and the communites along the way are fairly isolated otherwise.
But at 14 RPM's and given the mass, I would have to wonder about whale strikes. If there were sensors that detected the presence of whales (hugely easy with their lungs full of air) and conducted an emergency shut down, that would be a good thing.. With the variable pitch it should be easy to quickly halt rotation.
So that is what Steorn decided to work on after their failed technology demonstration late last year.
I love the idea of tapping into what the moon gives us free! If you run a 16 meter diameter rotor at 14 rpm, that puts the tip speed up to about 26.23 mph. Does that seem a bit aggressive for larger marine life?
Soarhead
I think this concept is fundamentally flawed. It is more or less taking wind tech and moving it underwater. It solves very few of the problems with wind tech and creates a lot more. The technology it is based on has high maintenance costs, and I can’t see them getting any cheaper by moving them under water. We need to try some completely new ideas, such as the rubber tube idea from a few weeks ago.
As the builder of the first trial version of the Tidal Turbine in the UK, I totally agree, which is why I looked at a 'Tidal Fence' concept (but then found that it doesn't work hydraulically) and ended up with the 'Tidal Reef' design that is almost totally environmentally benign but produces almost as much power as a full blown barrage. The sums of money being talked about on most of these schemes is rediculous. There is a place for straightforward basic engineering using simple fixed flow concrete turbines rather than sophisticated double regulated kaplan turbines. Most of the environmental damage is caused by the high differential head and the short generation period. There may be a place for tidal stream turbines in single units or small arrays in remote locations but it certainly doesn't make sense in an estuary location.
I am VERY pleased to read that electrical power is being produced from tidal movement, but I am concerned that so much of the production equipment is under (salt)water. A very hostile environment. That seems a very basic flaw.
rtjr
Manufacturing in the United States is in trouble. That's bad news not just for the country's economy but for the future of innovation.
On Twitter
Become a Fan on Facebook
Subscribe to the Feed
DJTal
154 Comments
Cost effective ?
I know they say that this technology is in the early stages and so still quite expensive , but it is way more expensive than tidal barrage technology at the moment . The Severn Tidal Barrage project , spanning the Severn estuary in the UK is estimated to cost £15 billion and will generate 8600MW on average . That's £1.75 million or $3.4 millon per MW . Barrage technology is well proven and available to us right now .
Reply
SHORELINER11@YAHOO.COM
2 Comments
Re: Cost effective ?
The difference is the tidal barrage will most likely have a great impact on the local environment. Trapping large quantities of water and restricting flow changes the hydrology of the environment. We've all seen the effects hydropower dams have on ecosystems, none of them arguably being good. I think this is a step in the right direction.
Reply
DJTal
154 Comments
Re: Cost effective ?
All the evidence suggests that a tidal barrage would have beneficial effect on the estuary ecosystem . The water would become less turbulent and clearer , allowing increased growth of plant life , which can then support a wider range of species . The evidence from the tidal barrage at La Rance in France indicates that the ecosystem is in a healthy state , with no loss of species diversity . Tidal barrages are very different from any other hydro power project since the water is able to move in both directions through the system , allowing wildife to pass safely through . We need different solutions for different situations , just like we do with solar power , and one of those solutions is barrage technology .
Reply
Shoreliner11
9 Comments
Re: Cost effective ?
What you're talking about may be beneficial for some species, but all in all you're still fundamentally changing the parameters of an ecosystem. A reduction in turbidity implies a reduction in water flow, which would mostly in some way be detrimental to the environment. Tidal currents have been shown to directly influence when certain species spawn and/or settle. So disrupting this flow, could detrimentally effect those organisms.
I'm not arguing that we don't need different solutions in different areas. I am trying to point out that the environmental impacts of each are very different, and a more expensive option that is better for the environment may be worth the $$$.
Reply
DJTal
154 Comments
Re: Cost effective ?
Or perhaps the money saved by creating a cheaper barrage could be used to protect an area of rainforest in some poor part of the world , which is undoubtedly of far greater ecological value .
Reply