The Electricity Council and boards are seeking to reduce the cost by developing cheaper methods of insulation, including the use of plastics and gas-filled cables. They are also studying the feasibility of using super conductors, although there are considerable technical problems to be overcome before this method is likely to be practicable, and ways of reducing the cost of transmitting electricity underground by direct current.
Will the Parliamentary Secretary say whether there is any prospect of this research reducing substantially the price differential of 18 to 20 times between the alternative methods? Secondly, can he confirm that the amount spent by the Central Electricity Generating Board on research in this field is about £100,000 to £200,000? Is he satisfied that that is a sufficiently high priority?
On the last part of the hon. Gentleman's supplementary question, I am satisfied that no promising project is being neglected. On the first part, it is difficult to estimate how much the ratio between the cost of overhead lines and that of underground cable may be reduced as a result of research. We hope that reductions would be made, but even on the most optimistic estimate the capital cost of high voltage cable will still be much greater than that of overhead lines.
I am sure the House knows that it costs about £1 million a mile for a 400 kV cable to go underground compared with £54,000 for overhead lines. Those are some of the figures involved.