On 15/12/2012 21:31, Tim Streater wrote:
Same sort of issue really. You could have a tidal barrage across the
Severn, and then one or more across, I dunno, the Humber or something
(anyway, somewhere where the tide is 90deg out of phase with the Severn).

Morecambe Bay IIRC.

"H R Wallingfords research consisted of both on site measurement and
modelling and identified that the maximum outputs for power production
outputs in the Bay could be as much as 2-3GW."

http://www.imeche.org/knowledge/industries/power/news/bridge-across-the-bay

The biggest Severn scheme, if Wikipedia and the Beeb can be believed, is
8Gw. For 8 hours per day, and not at neaps.

Andy