A "completely new kind of wave power machine" which resembles a giant swimming sea-snake could be generating energy off the coast of the UK within five years, its developers said today.
Each "anaconda", a device which could be up to 200 metres long and made almost entirely of a rubber tube, could 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 nine-metre version of the anaconda is currently in the final stage of "proof of concept" testing at a 270 metre wave test tank run by QinetiQ in Gosport, Hampshire.
The test tank is the largest in the UK and can simulate the strength and frequency of the ocean waves the device would encounter in the sea.
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.
The anaconda is harnessed to the sea floor, and unlike other wave energy machines "swims" head-on to the waves, like a ship in a storm, according to Professor Rod Rainey who came up with the original idea.
The waves in the sea stimulate a "bulge wave" which passes down the tube like a pulse of blood in an artery, gathering energy to drive a turbine in its tail.
The electricity generated by the turbine would be captured and carried to shore by cables.
Smaller versions of the device could be located alongside offshore wind farms where they could use existing grid connections to transmit electricity back to land.
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.
Checkmate's chairman Paul Auston said the anaconda could help to meet EU targets to source 15% of all the UK's energy needs from renewables by 2020 - the lion's share of which is currently expected to be met by wind power.
He said: "I think wave power has always been as the poor relation of wind energy, but a lot of people are resentful of wind turbines on their doorstep, or in vast tracts of coastal waters.
"What we're offering through Checkmate is a new technology which you can't see, it's under the water so it's not as intrusive and it's made of a natural material.
"It has major benefits to the environment and, we think, to people generally," he said.
While he said it was too early to put a price on the anaconda, he said the company was confident that they would be able to develop the technology so that it was affordable and competitive with other renewable resources such as wind.
And he said Checkmate wanted to deliver a device that was not dependent on subsidy, and was continuing to "narrow the gap" in costs.
Early stage development was backed by the Carbon Trust which said the anaconda had the potential to deliver breakthrough reductions in the cost of energy, and be much cheaper than the current best renewable energy devices.
The developers also hope the scheme could create a sizeable number of British jobs in the renewables sector and provide export opportunities to other countries in the world where wave energy could be harnessed along the coast, such as the US and Australia.