Letters: Wind farms cannot replace fossil fuel

As a one-time chartered electrical engineer and also a long standing member of the RSPB it was with increasing dismay that I read through the letter (23 September) from Messrs Dixon, Austin and McLaren of the WWF, RSPB and FoE (Scotland) respectively.

To refute all their misunderstandings, ill-understood technicalities and flawed recommendations would require at least half a page of this newspaper. I shall content myself with addressing one simple misconception and that is their weird belief that wind farms can replace fossil-fuel electricity-generating plants.

The reality is that winds sometimes blow strongly and sometimes weakly and sometimes not at all, but because electricity is needed all the time, every wind farm has to be "backed up" by fossil-fuel fired plant of equal installed capacity.

When the wind blows, wind farm electricity can replace some, but not all, of the the fossil-fuel plant output and so reduce some, but not all, of its carbon emissions. When the wind doesn't blow the back-up plant takes over.

The above consortium is proposing that by 2020 wind farms should provide 100 per cent of Scotland's electricity needs.

This will require about 3,000 turbines with a total installed capacity of 10GW backed up by 10GW installed capacity of fossil fuel-generating plant. Perhaps seven or eight large coal fired power stations?

Instead of protesting against plans to build a coal-fired power station at Hunterston, they should instead be enthusiastically supporting it and pressing for the construction of the other six or seven. Only then will their cherished wind farms be a viable proposition.

William Oxenham

Easter Currie Place

Currie, Edinburgh

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It is interesting to see the RSPB writing, in concert with other "environmental" subsidy lobbyists, for more government bungs to wind farmers.

A school which spent 20,000 on its own windmill recently turned it off because the sight of its continuous shredding of birds was not helping them give the pupils the desired "alternative" indoctrination.

Since the total number of birds killed by windmills is clearly many orders of magnitude more than those killed in the Caribbean oil release perhaps the RSPB could endorse something less harmful to its alleged clients, like more oil spills.

Neil Craig

Woodlands Road

Glasgow

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To produce 80 per cent of Scotland's electricity, never mind 100 per cent or even 50 per cent, from diffuse renewable methods (your report, 24 September and Letters, 23 September) some large-scale method of storing electricity would be required.

This is because the load factor of such methods is invariably below 50 per cent (wind is around 30 per cent but sometimes as low as 10 per cent); in 2008 such methods produced less that 20 per cent or our electricity.

In other words, the annual production from renewable methods can never exceed the load factor, which is a measure of how much time a generator actually spends generating.

Extra power can come from hydro (only about 9 per cent in Scotland) and other intermittent renewable methods (photovoltaic solar and tidal), but storage will still be required. The only large-scale storage at present are the pumped storage schemes at Foyers and Cruachan, but their combined capacity is only 700 MW.

Since Scottish demand can sometimes reach 7 GW (7000 MW), a storage system at least ten times greater than the pumped storage schemes would be required (more to meet rising demand in the future). Is this practical? It would be simpler to build new nuclear power stations.

Steuart Campbell

Dovecot Loan

Edinburgh

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While renewable energy generation will make an increasingly important contribution to the energy mix, there remains a need for reliable base load energy generation capacity to cater for the variable nature of electricity generated by wind and wave energy sources.

Given the anticipated closure of existing power stations across the UK over the next decade there is a need for replacement based load generating capacity to provide security of electricity supply - if not when the wind does not blow the lights won't come on.

The Scottish Government supports the development of low carbon power generation based upon Carbon Capture and Storage (CCS) technology of the type proposed by Ayrshire Power for Hunterston, a project which will enable Scotland to use its inherent skills and offshore assets to lead the world in the development of this technology.

The economic benefits of establishing Scotland as a world-leader in CCS are hugely significant, placing Scotland at the heart of the global drive towards low-carbon electricity generation.

It should also be noted that the cost to tax payers and electricity consumers of the development of renewable energy capacity is significantly higher than for the development of CCS - a major consideration in the light of current financial constraints.

Mike Claydon

Ayrshire Power Limited

Robertson Street

Glasgow