Inflexible power

The UK strongly promotes nuclear and wind power. These forms of generation have common features but make uncomfortable bedfellows.

Both are inflexible. Nuclear is essentially base load, due to huge capital cost but low marginal cost, and wind power is weather-dependent.

Both are government favourites because by 2020 they will be operating without CO₂ emissions, albeit having created vast quantities during construction — a conjuring trick favoured by governments to comply with 2020 CO₂ and renewables directives, but useless in reducing atmospheric CO₂.

But it will create quangos and bottlenecks, a point made in the feature 'Collaborate for change'.

Windpower is already criticised for extra standby capacity required, but waste could also occur when widespread strong winds blow at off-peak periods. The wind farms' average output of 15 per cent will then rise to their installed capacity of over 45 per cent and, with nuclear's 25 per cent, the sum will easily exceed off-peak demand, requiring the wind turbines to be feathered to limit output.

This will cause their utilisation factor to further drop, and the more the wind blows, the utilisation of conventional power stations also drops, dissuading further private investment.

As regards Martin Francis' suggestion of 'a string of nuclear stations along the French coast' (Letters, 14 July) such a concentration of distant power would need ultra-high cost transmission.

But the lights will not go out. Technically, peak load lopping by voltage reduction and insertion of gas burners into 'forbidden' coal boilers will see us through. Carbon trading, offsetting, exporting manufacture and importing biofuels will miraculously give 2020 compliance.

P Field

St Albans, Herts