Storage technology can help renewable sources

Alan Clayton (Letters, 15 August) has failed to understand the value of pumped storage, such as Ben Cruachan, for the Scottish electricity system. Pumped storage is used for two primary roles, first helping to balance generation and demand, and secondly, helping to regulate the grid voltage and frequency.

Nuclear power stations can only change their output slowly and so they sell cheap power at night when they are not required, partly for storage heating systems and partly for pumped storage. But the same technology can be utilised to maximise our uptake of renewable energy, wind or other sources.

Many renewable energy sources are intermittent and the same storage technology can be utilised to take wind power when the wind blows, and store for periods of high demand or when wind output is lower. Ben Cruachan is not a source of "generation", but is simply a system for storage of energy.

Mr Clayton is wrong when he suggests a wind farm consumes more energy in construction than is gener-ated in 25 years. The average energy pay-back period for a wind farm is between five to seven months.

Given that conventional technologies and nuclear utilise finite energy resources, when the energy value of their fuel and from construction are included, they consume many times more energy than is generated as electricity. This is why wind energy is the fastest growing energy technology in the world.

ROBERT FORREST

Chief Executive

Scottish Renewables Forum

Cooperage Way

Alloa, Clackmannanshire