IN your report on the shutdown of one reactor at Torness for a valve repair (“Reactor powered down as valve trouble is uncovered”, The Herald, March 18) you quote WWF Scotland as asserting: “It’s clear that nuclear power is showing itself to be an increasingly unreliable source of energy … Scotland is right to be choosing to harness more power from renewable energy sources” to “end our reliance on unreliable and unpopular nuclear power and fossil fuels”.

Implying that our existing nuclear stations are unreliable is not borne out by fact.

Since privatisation it is only the politicians who are responsible for ensuring we have adequate energy generation in the UK and since we have had no energy planning or researched strategy in place since 1990 the reality is that we need to keep ageing nuclear stations operating to supply base load as we cannot reliably depend on the outputs from renewable sources (predominantly wind) into which we have blindly and ignorantly invested so much.

It is worthwhile considering the reported visit to Orkney last week by the Scottish Affairs Committee of the House of Commons, chaired by SNP MP Peter Wishart, which held an evidence-gathering session on issues such as grid capacity and the lack of a cable capable of exporting electricity to the Scottish mainland. One keynote of the inquiry is to look at recent decisions by the UK Government particularly regarding on-shore wind and renewables generally.

Regarding wind reliability, on March 9, 10, 11, 14 and 15 I randomly checked existing Orkney wind output and the committee would have found the figures sobering. However it repeated the usual political hyperbole that “some things we all know, for example, that Orkney is self-sustainable when it comes to renewables”.

My random daily checks showed that during these five days Orkney was not exporting any energy at all. Orkney was importing between 50 per cent and 90 per cent of its needs. It was only generating between one per cent on March 9 to a maximum on March 13 of 18 per cent of its current installed wind capacity of 57,000kW.

In fact this was the second major lull experienced in Orkney within a couple of weeks, the previous being from February 24-26 (and probably longer).

Indeed at 9.59 am on February 26 the entire measured windfleet of 57,000kW in Orkney was producing 4kW when Orkney’s was using 24,000kW.

That is barely enough to power two kettles for a population of more than 20,000.

Before we are rushed by the politicians to intensively plant Orkney with wind turbines, and the consequent threats that some consider it will bring to its native, and rare, birdlife – which does not seem to concern WWF – we must question how reliable an energy source more wind generation would provide.

The answer is that it will always be much less reliable than nuclear and if the interlink is DC, as has been proposed, will not help support frequency or provide reactive power to help prevent voltage collapse in the already fragile north of Scotland grid.

DB Watson,

Saviskaill,

Langdales Avenue, Cumbernauld.