JENNY Hogan ("Time truth was told about the vital role of renewables in our wellbeing", Agenda, The Herald, April 22) makes the case that the continued growth of renewables in Scotland is an essential response to climate change.

However, Scotland has been delivering copious low-carbon electrical energy through nuclear since well before climate change became a political issue. Indeed, nuclear is our single largest generator of electrical energy, with the output from only two compact plants at Hunterston and Torness far exceeding the combined output of every wind, wave and solar generator in Scotland.

The sole result of the future growth of renewables in Scotland, mostly through onshore wind, will be the replacement of long-lived, compact baseload nuclear capacity with short-lived, diffuse and intermittent wind capacity once Hunterston and Torness close in 2023.

But worse, due to its intermittent nature, wind requires significant fossilfuel capacity to ensure that demand is met. Wind is in fact enabled by fossil fuels, and locks in their use, while nuclear replaces fossil fuels, in particular the most polluting baseload coal plants.

Colin R McInnes,

23 Williamwood Park West,



I NOTE with interest Jenny Hogan's article and Jack Ponton's response (Letters, April 24). There are, however, two further claims made by Scottish Renewables that I believe are misleading.

Large-scale energy storage is the elephant in the renewables room.

Utilising pumped storage when generating one-third of our energy from wind, we would require a further 97 Cruachans to withstand a three-day lull across the UK. Such lulls are not infrequent. This is a topographic,geological and geo­graphic impossibility. We simply cannot do it.

The recently-mooted cost for doubling the size of Cruachan is £1bn, with much infrastructure already in place, giving an approx­imate related total cost, were it feasible, of around £175bn.

It is also the case that pumped storage uses energy; it takes up to 25% more energy to pump the water to the upper reservoirs than is generated on release, so at best it is partial storage.

Whilst researching the perform­ance of the Pelamis wave energy devices from last year's results (following nine years of sea testing) when preparing a major review (since published), I established that with the then-current model it would take Pelamis, operating continu­ously, at least 16 years to go "green" - that is, generate the energy it took to build it. It was no surprise, therefore, that Eon withdrew its support. Subsequently, the Energy and Climate Change Directorate wrote to me confirming: "Clearly the technology needed to utilise and harness Scotland's wave and tidal power is in its infancy..."

As a chartered electrical engineer I support the research, but the general public who provide the subsidies should be appraised of the energy facts.

DB Watson,


Langdales Avenue,