Thursday, May 7, 2009

Ocean electricity generation draws nearer


I've been wondering for some time why we've heard so little about generating electricity from tidal and wave motion. So-called 'wind farms' are all very well, but they're notoriously unpredictable as reliable generators of electricity (when the wind dies down, so does your electricity supply), and they kill tens of thousands of birds each year, which fly into their huge rotors. They're not a satisfactory solution. Wave motion, on the other hand, and the rise and fall of the tides, is a constant, and doesn't die down with the wind.

Now a report from England says that a new type of electricity generator, to be moored offshore in deep water, is nearing full-scale testing.

It looks and moves like a like a giant snake, but according to scientists this weird device could be generating energy off Britain's coast within five years.

Each 'anaconda', which could be more than 200 yards long and made almost entirely of a rubber tube, may be capable of producing 1MW (megawatt) of power.

The plan is to have 'shoals' or 'schools' of the devices around the coast, where they would be harnessed to 'swim' just below the surface.

Groups of 50 anacondas could each generate enough electricity to power 50,000 homes at an 'excitingly low' cost, the developers Checkmate Group said.

A ten-yard version of the anaconda is currently in the final stage of 'proof of concept' testing at a 300-yard wave test tank run by QinetiQ in Gosport, Hampshire.

Checkmate hopes to be testing full-scale devices in the ocean within three years, with the first anacondas in commercial production and deployed off the coast by 2014.

. . .

Prof Rainey, a chief engineer with engineering design consultants Atkins, said: 'It's a completely new kind of wave power machine.'

And he said: 'The beauty of wave energy is its consistency. However, the problem holding back wave energy machines is they tend to deteriorate over time in the harsh marine environment.

'Anaconda is non-mechanical: it is mainly rubber, a natural material with a natural resilience and so it has very few moving parts to maintain.'

He added that the design was 'tremendously survivable'.

'If the worst comes to the worst it'll only be washed up on the beach, and you can patch it up and put it back out there,' he said.


There's more at the link.

Here's a video of the proposed system in operation.





I find it all very interesting. If enough of these can be moored in out-of-the-way places off the coast, a large proportion of our energy needs might be satisfied without using fuel of any kind. That can only be good for the environment.

Of course, they'll have to be careful to site these things clear of the habitat of the electric eel. Those things carry a charge of their own, and if one of them should develop amorous intentions towards an 'anaconda', the results might be literally shocking!



Peter

4 comments:

Peripatetic Engineer said...

I predict that maintenance on this thing will make it cost prohibitive. And mooring it below the serface to avoid ships decreases its efficiency. The particle motion in a wave drops off very quickly with water depth. I like the turbine units on the rocky coast of Scotland that use the wave to compress a volume of air. There are no moving parts in the water and anything that needs maintenance is accessable from land.

Billll said...

There are lots of funkey ways to generate electricity, and very few cost-effective ways to do it. A typical coal-fired power plant delivers about 1200 Mw. Those wave generators look like they would take a lot of real estate to do the same thing, as individual units would need to be spaced far enough apart to not interfere with one another.
Additional cost includes the spider web of cabling to connect all 1200 units together, most of which would be running in sea water, which is a hostile environment.
Assuming 250 square meters per unit, 1200 Mw would require 75 sq Km of boat-free ocean to install, and about 300,000 M of cable to connect.
The research probably pays the salaries of 50 or so people doing the research, though, proving that a PhD in EE isn't completely useless.

LabRat said...

Wouldn't worry about the electric eels- that's a freshwater species.

Electric RAYS on the other hand...

Ted said...

There's a facility of this type somewhere in Scandanavia. It cost millions to build, is very expensive to maintain, and generates enough power to provide electricity to something less than 100 homes.