Head Tidal Development Ltd renewable energy site has been awarded to a
venture company owned by OpenHydro and Scottish and Southern Energy
(SSE). The site is a three mile stretch along the
south coast of South Walls
(Hoy) and lies within the Pentland Firth
which is considered to be one of the world’s largest
single tidal sites. It is claimed that the site will be a major first
delivering, by means of undersea turbines, large scale tidal energy to
with this one project having the potential to
provide enough energy to power over 130,000 homes. Extrapolated from
published data this would mean that between 850-900 turbines [of the
tested] were required to meet this target
the next few years, the joint venture company says that it will be
closely with statutory bodies, local communities and others to complete
required surveys prior to bringing forward an application to deploy
undersea “open-centre” turbines.
Their Open-Centre Turbine
is designed to be deployed directly on the seabed and, it is said, will
be silent and invisible from the surface.
these turbines will be located at depth and present no navigational
hazard whilst providing, it is said, a significant, predictable and
undetectable supply of clean renewable energy.
claim that communities that benefit from power supplied by the undersea
turbine technology will never be conscious of the turbines' existence.
turbine is an example of a simple idea proving to be a most effective
solution to renewable energy generation.
functionality and robustness of such equipment in an underwater
environment is crucial. The turbines expect to meet these demands, with
a slow-moving rotor (about seven r.p.m) and a lubricant-free operation
minimising risk to marine life..
turbine has a number of design features intended to avoid any impact on
marine life. The large open centre, about 2 metres in diameter,
provides a safe passage for smaller marine life and the turbine's
hydrodynamic lines should ensure that fish will not become entangled. The minimal underwater
noise may prove sufficient to allow larger mammals to detour around the
scientific evidence seems
to exist concerning the impact of such undersea turbine developments on
or the environment. Nor
appear to by any planned other than a three year research project,
to determine whether sea mammals can detect noise from the turbines
and, thus, can
avoid colliding with them.
All we know for sure is that the
introduction of undersea turbines (and exclusion of some types of
bring about some changes for species and habitats, but nobody can say
at this point what those changes will be.
Present knowledge – based on offshore
windfarms seems to be that there
may be some disruption during the installation stage but no evidence of
to marine life has been witnessed.
scientific consensus, therefore, seems
to be to install the turbines and then observe the consequences: early
should be available from turbines already installed in the Channel Islands and Canada.