Let's have a smaller pilot barrage first

Recent discussions by the ICE and a seminar hosted by the Royal Academy of Engineering last month highlighted the many environmental issues surrounding the use of River Severn's tidal power to generate electricity.

An enormous input of finance and resources – involving up to 45,000 personnel – would also be required to construct a Cardiff to Weston barrage capable of providing 5% of the UK's electricity.

It seems to me that it will be a very audacious and brave government that will commit to building the Cardiff-Weston barrage when no power will be generated until it is complete, perhaps a full generation in the future.

A pilot scheme would be attractive if constructed quickly to produce power and which would economically form part of the barrage.

A possibility is an enclosed lagoon with turbines to generate power, using the 14m tidal range in a deep part of the estuary on the alignment of the barrage into which it would eventually be incorporated.

A lagoon of, say, 3.5km diameter would form some 32% of the 11km length of the concrete barrage.

The pilot scheme would be a proving ground for the full barrage and the experience gained in construction methods and ground conditions would be invaluable with the potential of reducing costs.

It is to be hoped that the current government study will consider the feasibility and benefits of a pilot scheme to produce carbon-free power
at an early stage in the realisation of this tremendous project.

ALAN HAYWARD (F), 3, Tutshill Gardens, Chepstow NP16 7DW