Tidal power opportunity proposed for Bristol Channel

A marine fence across the Bristol Channel, now at the planning and development stage, is estimated to have the potential to supply 5% of Britain’s energy needs from tidal power.

The fence, proposed by Kepler Energy, an Oxford University spin-off company, would use horizontal water turbines that work rather like water wheels. It would be built between Minehead, Somerset, and Aberthaw, 15 miles west of Cardiff, South Wales.

The current would back up against the fence to drive the turbines. The fence, made from carbon composite materials, would be at depths of between 20m-30m with a clearance of five to ten metres at mean tide.

Kepler maintains the simple design makes the fence less expensive and more reliable than previous proposed barrages and dams across this stretch of water.

If the plan receives the go-ahead, the fence could be operational within six years. The cost is put at £143m ($221m, €201m).

Kepler chairman Peter Dixon, with one eye on more similar schemes, said: “As our tidal technology can operate in lower-velocity tidal waters, there is greater scope for its deployment in the UK and overseas. It means that we can achieve greater economies of scale as our projects are deployed.

“We can happily co-exist with tidal lagoons, and the power peaks will occur at different stages of the tide, meaning that the combined output into the grid will be more easily manageable. In summary, tidal fences offer a very practical and cost-effective source of utility-scale renewable energy.”

Kepler is now conducting a rigorous environmental assessment of the Bristol Channel scheme and is seeking funding.

The plans have already gone to the government’s energy and climate change department, the devolved Welsh government, Bristol city council and The Crown Estate, which administers government-owned property. A stakeholder consultation programme will follow.
The news coincides with a new report from Frost & Sullivan which states that the UK is the market leader in the development of tidal energy solutions.