First Minister's case for wind energy is brave but woefully misinformed
First Minister Alex Salmond makes a brave case for Scotland to be a world leader in energy and in reducing harmful emissions to produce clean, green energy (Opinion, 13 May).
He strongly promotes the case for wind energy and asserts that ten offshore wind sites in Scottish territorial waters have the potential to generate 6GW of electricity; it is assumed that these are shallow-water sites as deep-water sites are not economically viable at present. However, it may be wise to question the ability of the available sites to achieve such a huge generating capacity. Mr Salmond would be well advised to refer to an excellent book by David Mackay, Sustainable energy without hot air, which provides a much more accurate perspective on offshore wind generation.
To summarise one or two key points: a potential of 6GW means an average output of just 2GW and an installed capacity of 6GW would require a shallow sea area of around 10,000 km. It seems unlikely that such a large area of suitable coastline can be utilised. There is also the question of sustainability as the corrosive effects of sea water on wind turbines have a significant impact on whole-life costs when compared to onshore wind turbines. In addition to installation costs, consideration should be given to the huge quantities of concrete and steel required in their construction, which will be much greater than that used in the construction of a nuclear power station and thus involve significant production in their manufacture.
However, to be fair to Mr Salmond he is advocating a mix of renewable energy sources together with clean coal combined with carbon capture. It is, however, regrettable that for political rather than practical reasons he excludes nuclear power from the mix.
First Minister Alex Salmond's claim that nuclear power is unreliable and unwanted in Scotland ("Scotland's energy-rich potential is unrivalled", Opinion, 13 May) is flawed and seems to indicate that he is out of touch.
Due to occasional breakdowns, no method of generating electricity is completely reliable. However, because it can supply when required, generation via a steam or gas turbine is regarded as the most reliable method (nuclear stations generate via steam turbines). Measured by load factor (the proportion of time plants operate at designated capacity compared with operation at that capacity 24/7), nuclear stations are at least three times more reliable than wind farms, perhaps the most unreliable generation method ever devised. In fact, all renewable energy methods are more unreliable than thermal generation.
As an example of reliability, over the five years from 2004-09, both units at Torness have been off line simultaneously for only just under 2 per cent of the time; so it has been generating for 98 per cent of the time over those years.
As for being unwanted, in March 2009, the Scottish Government surveyed 3,000 people about their views on all types of energy. It found that 53 per cent were in favour of more nuclear power, with only 23 per cent against.
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Thursday 20 June 2013
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