The UK's Environment Agency's Horizon Scanning Team has found the nation's rivers are full of untapped energy in the form of fish migrating upstream.
By installing networks of electric prongs along the riverbed, the energy can be captured and fed into the National Grid, reports the Daily Telegraph.
Environmentalists welcomed the opportunity to not only generate clean energy but ensure rivers are maintained for wildlife. However, there was concern that areas for fishing could be out of bounds in future and wildlife or even fishermen could be electrocuted by the prongs.
The project, codenamed 'Finetics', builds on Japanese technology that captures energy from people walking over pressure sensitive mats at train stations.
Research found that a typical salmon, which zips through waters at a top speed of 12 metres per second, can over a 100 metres stretch generate enough electricity to make 18 cups of tea, while the shyer rudd will only trigger enough power for three cups.
Multiplied many times over by the millions of fish that thrive in rivers and waters across England and Wales, the Environment Agency scientists estimate the amount of electricity generated could power around 30 000 homes a year.
Dr Andrea Pool, who heads up the Horizon Scanning team, said: "Initially we looked at working with sheep and cattle as well as fish, but it quickly became apparent that the energy-generating potential of fish far outweighed that of slow-moving grazing stocks. Plus, fish populations are the healthiest they have been as a result of huge improvements in water quality over the past two decades."
A three-month trial of the technology was conducted last summer at a secret location on the River Tees, which has seen salmon numbers increase to record highs. In that period enough electricity was generated to power a typical family home for a year.
Plans are now underway for a large scale trial over a year along the River Severn because it has such a strong tidal current which forces fish to move at optimum speeds as they swim upstream. This will help to ensure the technology can be rolled out across England and Wales in the future.
Gavin Roach, a world-leading specialist in green technologies based at the Université de Poisson d'Avril in Paris, who will monitor the forthcoming trials, said: "The Environment Agency team has made a very exciting breakthrough. Finetics clearly has the potential to create significant amounts of power by simply harnessing the power of nature."
However, campaign group Freedom for Fishermen said it was a potential danger to the 4m people in the UK who fish as a hobby.
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