Byline: Peter K Jones
"A TIDAL barrage would fundamentally change the nature of the Severn Estuary" - this was the conclusion of the Sustainable Development Commission (SDC) in its report last October to the UK Government - Tidal Power in the UK.
The report had been commissioned following a recommendation from the Welsh Assembly Government (WAG) in May 2006 that it was now "appropriate to re-examine the Severn barrage proposals in depth".
The SDC report focused very much on the proposal for a 16 kilometre embankment that would link Lavernock Point in Penarth with Brean Down in Somerset, known as the Cardiff Weston barrage. However, the report also considered a much smaller option, known as the Shoots barrage. Both barrages would be designed to harness for electricity generation the high tidal range of the Severn Estuary.
Since publication of the report, the UK Department of Business, Enterprise and Regulatory Reform (DBERR, formerly the DTI) has started a two-year feasibility study into the potential for energy generation from alternative tidal range locations.
Electricity output - potential electricity output from the Cardiff Weston barrage is estimated at 4.4% of current UK consumption.
With an estimated construction cost at current prices of pounds 15bn, the barrage would be three to four times more expensive than other forms of large-scale generation.