Oxford University spin-off aims for tidal power “fence” in Bristol Channel

Kepler Energy, a commercial spin-off from the University of Oxford’s department of engineering, is seeking $220m in funding for a "fence" of energy-generating turbines in the Bristol Channel in western England.  

The first project would be to install a 1km barrier with a generating capacity of 30MW, although Kepler hopes to scale this up to 600MW over time.

We’ll be having some intensive discussions with the Welsh government because that is a very good location with access to EU regional development grants– Peter Dixon, chairman of Kepler Energy

The scheme would use the second-generation tidal turbines developed by the university department.  

These use a horizontal carbon fibre "roller" design rather than the conventional propeller configuration.  

According to Kepler, these sweep a greater area of the tidal flow and have an output "several times higher" than their predecessors.  

The fence is expected to be located between Aberthaw in Wales and Minehead in Somerset. 

Peter Dixon, the chairman of Kepler Energy, told GCR: "I imagine it would go somewhere north north-west of Minehead. It can’t go in the shipping lane or very shallow areas but at 1km long the initial proposition is not for a very long fence. The first step will be to look carefully at the precise locations." 

Kepler is hoping to attract a mix of public and private funding. Dixon said: "We’ll be having some intensive discussions with the Welsh government because that is a very good location with access to EU regional development grants."  

He added that Kepler had interest from private funders. 

Kepler says that if the fence receives funding and planning approval it could be operational within six years, after which further turbines could be added as the investment became available, with the ultimate aim creating a "serious, utility-grade" facility with a capacity of 600MW.  

According to Kepler, a typical turbine rotor would be 10m in diameter and 6m long, and sited in a tidal flow with a mean depth of 20m.  

Flume tests on a scale model have shown that the basic configuration of two turbines with one generator should generate more than 4.4MW at a water velocity of 2m/sec, and more than 5.2MW at a water velocity of 2.5m/sec. In addition, the unit will operate with reasonable efficiency at low water velocities.