THE WWF, Friends of the Earth and RSPB Energy for Scotland publication, supported by funding from the People’s Postcode Lottery, envisions that by 2030 Scotland will “have achieved a low cost, maximum benefit energy transition … Scotland capitalises on its tremendous natural resources, generating the equivalent of 143 per cent of electricity demand from renewables, with substantial exports to the rest of the UK. An additional 7-8GW [roughly doubling renewables] is built, security of supply is maintained and up to 14,000 new jobs are created.”

Their report co-opts an earlier 2014 study they commissioned which asserted that “electricity supply in Scotland will be secure if the combined GB system is secure … with the transmission capacity to the rest of the GB currently existing or planned, there is little or no need for conventional generating capacity in Scotland to maintain security of supply”.

Their model presumes this to be achievable and has therefore apparently been run without the inclusion of any related “key defined, quantified, engineering constraints”. This therefore restricted the possible set of “feasible solutions” providing results that, technically, cannot be treated as a viable vision for the development of Scotland’s energy future..

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The achievement of “Security of Supply” first needs “Security of Operation” in our electrical grid.

The model fails to address the future control of frequency, of great concern to National Grid (NG), as large generators and their inertia are removed. There is a required provision of huge replacement levels of reactive power throughout Scotland (1000MegaVars), with one-third in England, to prevent Scotland’s voltage from collapsing. NG has called for huge “agility” investment in its UK gas grid, commenting that “because of variable patterns of generation and failure from wind turbines the system is having to respond to short notice and high ramp up rates for the start-up of gas turbine stations to sustain our electricity supplies” and that to balance the system it may have to cut gas supplies to industry this winter.

Neither is the increased Loss of Load Probability (system collapse) addressed, which is increasing from four failures per 100 years towards once every two years as we increase renewables.

The reality is that Scotland is already dependent upon England and Wales for security of operation to control voltage and meet demand.

The National Grid 2016 Winter Outlook Report expects the reliable UK electricity margin to be 1.1 per cent bolstered to a maximum of 6.6 per cent from having secured a re-start of Eggborough coal-powered station, from failure of the Moyle HVDC link to Northern Ireland reducing our exports, and an expectation that the two interconnectors to France and Netherlands can be importing at two-thirds capacity. The UK has no firm contracts in place guaranteeing these imports.

From October 30 to November1 UK-wide wind generation collapsed, typically supplying only 0.88per cent, 1.07 per cent and 5.16 per cent of our energy with gas generation having to provide 54 per cent, 58 per cent and 56 per cent.

The stock market is cold-eyed and impatient. Several generating companies are attributing big profit falls to lack of wind and are significantly underperforming the FTSE-100. Fund managers will have noticed.

DB Watson,

Saviskaill, Langdales Avenue, Cumbernauld.