§ Mr. McKelveyasked the Secretary of State for Energy (1) what has been the highest maximum demand upon the electricity grid in England and Wales in the current winter and the highest over the last five winters; and what margin of spare capacity was available on each occasion;
(2) what is the plant margin of generating capacity in the electricity supply industry in England and Wales, Scotland and Northern Ireland.
§ Mr. John MooreI am advised by the CEGB that the highest demand met by the board's system (restricted maximum system demand), and the amount of its own plant available at that time were:
303W
Megawatts A B C Year Restricted maximum system demand (MSD)* Total CEGB plant output useable at MSD† CEGB plant useable in excess of system required per cent. 1977–78 42,803 44,532 1,729 4.0 1978–89 44,102 44,590 488 1.1 1979–80 44,225 46,974 2,749 6.2 1980–81 42,600 44,498 1,898 4.5 1981–82 42,597 43,421 824 1.0 1982–83 42,073 42,895 822 2.0 The margin of spare capacity in column C excludes any contribution from use of the interconnector with the South of Scotland Board and power from outside sources.
Electricity supply in Scotland and in Northern Ireland is the responsibility of my right hon. Friends the Secretary of State for Scotland and the Secretary of State for Northern Ireland respectively.
* Restricted maximum system demand takes account of reductions in demand achieved by load management.
† plant is the total declared net capacity of the CEGB system, less plant outages due to repair, maintenance and breakdown, and plant on short and long term reserve standby.