Electricity supply

Press, 24 July 1987, Page 16

Electricity supply

Sir, — If there is no demand limit for M.E.D. draw-off above which penal rates apply, why does the M.E.D. consider it necessary to cut off domestic water heating for (?) hours on June 30, three hours the following morning and, no doubt, on numerous other occasions? — Yours, etc., J. K. HENDERSON. July 15, 1987.

[The general manager of the Municipal Electricity Department, Mr C. S. Laurie, replies: “The bulk supply tariff by which all electrical supply authorities purchase their electricity contains charges for both energy used and maximum demand recorded. The demand charge is not a ‘penal rate,’ as your correspondent suggests, and there is no limit placed on levels of demand to the M.E.D. In order to reduce the cost of bulk charges, however, demands are reduced at times of heavy load by operating ripple control, and in this way retail electricity charges are kept to a minimum. Your correspondent may be interested to know that within the M.E.D. area ripple control of domestic water heating has been used very infrequently this year, with over-all control operations being less than one-fifth of those for the equivalent period last year.”]