Visit Wales Now
Visit Wales Now
Visit Wales and see some dramatic changes to the landscape
Excavation for the foundation of one wind turbine at Cefn Croes.
An
unspoilt environment?
Besides
being big, noisy and visibly intrusive, wind turbines have a lasting effect on
the landscape. Building a wind farm is a major construction project and the land
will never be the same again once the development is complete.
The
first step in building a wind farm is the access roads. These roads have to be
wide enough and strong enough to transport the turbine component parts, the
building equipment and the hoisting cranes into the site. The aggregate needed
to build these roads is usually dug out from the sides of the surrounding hills
from what is euphemistically referred to as ‘borrow pits’. In some
instances, these roads are invading pristine wilderness and will open these
areas up to vehicle traffic for the first time.
An
access road at Cefn Croes.
Turbine
foundations
Then
the foundations are dug. Each modern turbine needs a reinforced-concrete
foundation the size of an Olympic swimming pool. This requires about 1,000 tons
of concrete. The concrete is either transported in along the access roads or a
cement factory is set up at the site.
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A turbine foundation and concrete plant at Cefn Croes.
Note that a person is standing at the top left-hand corner of the foundation.
The
concrete foundations and the concrete standing pads, needed for the cranes that
erect the turbine towers, will remain in place forever. The developers are not
expected to remove the concrete at the end of the wind farm’s operating life.
A
wind farm also needs a substation and miles of power lines and pylons to
transport the electricity to the national grid. Wind farms are built far from
the urban areas where the electricity is needed, so most wind-generated
electricity is carried across great spans of open countryside.
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A substation and pylons at Cefn Croes.
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But don't wind turbines help reduce carbon dioxide (CO2) emissions ? Unfortunately not. In spite of what the power generating companies and the wind farm developers say, wind turbines have very little effect on the total emission of CO2 from fossil fuel power stations. The reason for this is simple. Energy output from wind varies from zero to 87% of their rated capacity, depending on the wind. If the wind speed is less than about 5 metres per second (11 mph), no electricity is generated; if the wind speed is greater than about 25 metres per second (56 mph), turbines are shut down for safety reasons. On average, wind turbines in the UK generate about 23% of their rated capacity. All
power plants need a certain amount of backup to cover down times, but wind power
is unique in that the down times are intermittent and unpredictable. The backup
for wind power must be running continuously, ready to go on stream immediately
in response to changing weather conditions. The crucial point here is that this
"spinning reserve" is burning fossil fuels and emitting CO2 even when
not producing electricity.
To
date it has been assumed as self evident that wind generated electricity will
save carbon. There is very little evidence that this is the case and indeed
mounting evidence that wind generated power is not carbon friendly. Current
available figures bring us to conclude that during
its lifetime one 3MW
turbine
will “save” 6,356 tonnes of carbon and “cost” somewhere between 27,213
and 40,773 tonnes of carbon. Dr.
Sarah Myhill, of Llangunllo, Powys,
has studied the problem. Click here to download her research paper. |