Thermal Efficiency (Hansard, 15 March 1976)

§ Mr. Woof
asked the Secretary of State for Energy what is his estimate of the savings that will result from the improvement of thermal efficiency consistent with the technology available in coal equivalent.

§ Mr. Benn
I understand from the CEGB that at current demand levels it is estimated that an increase of 0.1 per cent. in the thermal efficiency of fossil-fired plant results in a saving of 0.3 million tons of coal equivalent per annum or £5 million per annum. In 1974–75 the Board's conventional power stations achieved a record thermal efficiency of 30.6 per cent. compared with 29.78 per cent. in 1973–74. This improvement brought about a reduction in fuel consumption of 2.25 million tons of coal equivalent and represented a saving of £28 million in the Board's fuel bill.

§ Mr. Woof
asked the Secretary of State for Energy what improvements have been made in overall thermal efficiency of coal-fired power stations.

§ Mr. Eadie
I understand from the CEGB that the improvements in the thermal efficiency of their plant are due to 385W technological advances and economies of scale. The average thermal efficiency of fossil-fired plant of 60 MW capacity or similar—i.e., plant installed and being installed at the time of nationalisation—is currently of the order of 21.7 per cent. The thermal efficiencies of plant of a larger size, installed since 1947 are currently:

Unit size Thermal efficiency

MW per cent.

100–120 25.84

120–500 30.88

500–660 33.67

§ Mr. Woof
asked the Secretary of State for Energy what is his estimate of the amount of coal needed to meet present demand, assuming thermal efficiency at the 1933 level.

§ Mr. Eadie
The CEGB advises us that if the electricity produced by the CEGB's conventional plant in 1974–75 had been generated at the 1933 thermal efficiency

Proportion of total sales (per cent.)

Total sales (GWh) Iron and Steel Industry Other industries Domestic

1970 … … … 197,751 61 34.2 39.0

1971 … … … 203,433 5.3 34.1 393.7

1972 … … … 210,417 51 32.8 41.3

1973 … … … 225,267 5.2 33.4 40.5

1974 … … … 218,335 5.2 32.5 42.4

1975^* … … … 218,432 5.1 32.5 40.9

^*Provisional figures, including an estimate for Northern Ireland.

Unit size	Thermal efficiency
MW	per cent.
100–120	25.84
120–500	30.88
500–660	33.67

					Proportion of total sales (per cent.)
				Total sales (GWh)	Iron and Steel Industry	Other industries	Domestic
1970	…	…	…	197,751	61	34.2	39.0
1971	…	…	…	203,433	5.3	34.1	393.7
1972	…	…	…	210,417	51	32.8	41.3
1973	…	…	…	225,267	5.2	33.4	40.5
1974	…	…	…	218,335	5.2	32.5	42.4
1975^*	…	…	…	218,432	5.1	32.5	40.9
^*Provisional figures, including an estimate for Northern Ireland.