A brush with darkness

SIR – Lord Jenkin of Roding (Obituary, December 21) appealed to the public to “clean their teeth in the dark” during the energy crisis of 1973-74.

I worked with him as an adviser until after the passage of the 2013 Electricity Act and he was always looking to make amends for this remark. As a leading Conservative spokesman on energy in the Lords, he took every opportunity to criticise policies that he felt would undermine the security of the energy supply.

In 2014, in an article in The Daily Telegraph he warned the Coalition Government that keeping the lights on required more emphasis on underpinning new investment and greater competition in conventional gas generation and less emphasis on renewable energy. He was always searching for solutions that were in the best interests of the consumer. Clive Moffatt London SW1 SIR – Most power stations do use steam turbines (Letters, December 24), but the steam flowing through the turbines is pure and demineralised. It is condensed and reused on emerging from the last stage of the turbines.

This condensing is accomplished by using large volumes of cooling water taken either from the local river or from the sea. During this process, the cooling water becomes heated past the temperature at which it could be returned to a river. Hence the cooling water is itself cooled in the massive cooling towers referred to.

So what emerges from the top of these towers is nothing more than vapour from hot river water. Since the temperature of the cooling water is not a problem when it is returned to the ocean directly, there is no need for cooling towers on coastal stations. John Todd Stoke-on-Trent, Staffordshire