Smarter fresh air

SIR – I can understand people’s frustration (Letters, August 3) at the very negative reply by Claire Perry, the Minister of State for Energy and Clean Growth, on smart meters (Letters, August 2).

I don’t think she realises what a fantastic breath of fresh air it would be for a minister to change a policy that is obviously wrong. John Spiller

Bristol

SIR – I am grateful to Mrs Perry for clarifying that her predecessor jettisoned not a smart meter, but an energy monitor.

However, these devices should not be so lightly disparaged. Inaccuracy of clip-on monitoring devices arises from their failing to take account of the phase-lag between an AC voltage applied to a circuit and the resulting current intensity. In a domestic environment this phase lag is virtually never far from zero and over time it scarcely varies, so the inaccuracy is nugatory.

These devices serve very well as energy-consumption monitors. I formerly used such a device. However, since the manufacturer of the unit was subsumed into British Gas, production has ceased and I have found no replacement.

A slightly less convenient alternative is a single-socket monitor, which is as effective in supporting intelligent consumption management as smart metering. I commend these devices to the nation as a means of saving roughly £11 billion. Gerald Lessnoff

Wimborne Minster, Dorset