There has been a total collapse of the UK wind fleet output that coincides with the public debates on nuclear generation choices and fracking.

Once again this month as a result of the enjoyable late summer weather the UK has suffered several sustained and virtually complete collapses in its wind fleet output throughout at least 11 of the past 20 days of this month that I randomly checked.

The total installed wind fleet capacity in the UK as of last autumn was 12GW and has continued to increase since then as more turbines are commissioned.

At 10.40 on Saturday the UK total wind output was 0.15GW. This met 0.49 per cent of the UK’s needs and meant that windfarms were producing less than 1.25 per cent of their installed capacity.

This is equivalent to 6.7 per cent of the capacity of Longannet and, whatever proportion of it was generated in Scotland, it would be unlikely to have met the combined demand of our hospitals.

Throughout this month, our power imports from the continent continued at their present maximum interlink capacity of 3 GW (mostly French nuclear), meaning imports were 20 times greater than Saturday’s total wind generation.

The UK demand on Saturday was just over 30GW and in mid winter this could climb to around 55GW.

Ofgem forecast no more than an eight per cent margin in UK electricity availability over demand this winter if it is “average” weather, assuming the imports from the continent remain at the maximum of 3GW. Without imports our margin will only be two per cent. The French are making no promises as to availability. The sobering reality is that we will always continue to face periods of several consecutive days when the entire UK wind fleet, never mind just the Scottish wind fleet, will not produce anything like the capability of a Longannet.

There remain also considerable technical doubts within the electrical engineering profession as to whether Scotland’s interconnections to the rest of the UK, whilst being “reinforced” in the longer term, will be capable of responding adequately after Longannet’s closure, to prevent large scale supply interruptions in Scotland in the near future.

I invite the power companies to provide their calculations and results data that demonstrate they have produced rigorous power system analyses through cross-company liaison and whether these confirm future electricity supplies in Scotland and the wider UK are no less secure than

when the industry was privatised or demonstrate predicted heightened probability of interruptions.

DB Watson,

Saviskaill,

Langdales Ave,

Cumbernauld.