§ Mr. Skeetasked the Secretary of State for Energy (1) under current domestic tariffs, what is the cost of electricity consumed by a 65-watt white fluorescent tube over its expected life of 5,000 hours;
(2) under current domestic tariffs, what is the cost of electricity consumed by a 100-watt domestic tungsten lamp over its expected life of 1,000 hours.
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§ Mr. Eadie:I am informed by the Electricity Council that the present national average costs, based on area boards' unrestricted domestic follow-on rates would be £1.39 for a 100-watt tungsten lamp run for 1,000 hours and £5.56 for a typical 65-watt fluorescent tube run for 5,000 hours. The council also informs me, however, that the expected life of a 65-watt fluorescent tube is 7,500 hours for which the cost of the electricity consumed would be £8.34.
§ Mr. Skeetasked the Secretary of State for Energy if he will compare the measurement of light of a common 100-watt domestic tungsten lamp and its conversion efficiency with that of a white fluorescent tube of 65 watts.
§ Mr. Eadie:The light output of a common 100-watt domestic tungsten lamp is typically 1,500 lumens, i.e., 15 lumens/watt, and the light output of a normal 65-watt fluorescent tube is about 80 lumens/watt. These figures are necessarily approximate as they depend on many factors, including the age of the bulb or tube.