The capital required to construct a tidal barrage has been the
significant stumbling block too. It is not an attractive
proposition to an investor due to long payback periods. This
problem could be solved by government funding or large
organisations getting involved with tidal power. In terms of
long term costs, once the construction of the barrage is
complete, there are very low maintenance and operating costs and
the turbines only need replacing once around every 30 years. The
life of the plant is indefinite and for its entire life it will
receive free fuel from the tide. Few tidal barrages have been
constructed. The largest tidal power station in the world (and
the only one in Europe) is in the Rance estuary in northern
France. La Rance was completed in 1966 and has operated reliably
ever since. So too has the barrage at The Bay of Fundy in Canada
- though this had an adverse effect on Marine life. There have
been plans for a "Severn Barrage" from Brean Down in Somerset to
Lavernock Point in Wales. Every n