Machynlleth power stations

Machynlleth power stations were two small electricity generating stations in Machynlleth Powys. They provided electricity to the town and the surrounding rural district from 1938 until the 1970s. The A station was a combined diesel & hydro-electric plant and the B station was a diesel engine plant.

History edit

Machynlleth Electric Supply Company Limited (founded in 1932) proposed an electricity supply scheme for Machynlleth in 1938.[1] [2] The company constructed a combined diesel engine and water-turbine electricity generating plant, later known as Machynlleth A. Upon the nationalisation of the British electricity supply industry in 1948 the Electric Supply Company was abolished and Machynlleth power station was vested in the British Electricity Authority (BEA).[3] In 1956 the BEA’s successor the Central Electricity Authority (CEA) constructed the diesel-fired Machynlleth B, which was commissioned in September 1956.[4] One of the diesel engines of the A station was transferred to the B station in 1956.[4] The A power station was decommissioned in the 1960s, and the B station by 1978.[5]

Plant and equipment edit

A station plant edit

The plant at Machynlleth A power station comprised:[4]

  • 1 × 110 horsepower (82 kW ) Francis water turbine
  • 1 × 35 horsepower (26 kW ) Francis water turbine
  • 1 × 100 horsepower (75 kW ) diesel engine
  • 1 × 200 horsepower (149 kW ) diesel engine
  • 1 × 400 horsepower (298  kW ) diesel engine

The turbines and engines drove a range of alternators:

  • 1 × 23 kW Brush alternator
  • 1 × 57 kW Brush alternator
  • 1 × 66 kW Brush alternator
  • 1 × 104 kW Brush alternator

The total generating capacity was 250 kW, 3-phase, 400 V AC.[4]

B station plant edit

The plant at Machynlleth B power station comprised:[4]

  • 3 × 1,330 kW Mirlees 8-cylinder four-stroke supercharged diesel engines driving:
  • 3 × Brush 6.6 kV alternators
  • 1 × 268 kW Petters 4 cylinder two-stroke diesel engine with a Brush generator (transferred from the A station in 1956).

The total installed generating capacity of the B station was 4.258 MW.

Cooling water for the engines was drawn from the Afon Dulas.[4]

Operations edit

The operating conditions and electricity output of Machynlleth A power station were:[4] [6] [7]

Machynlleth A power station operating parameters 1946–63
Year Running hours Plant capacity kW Electricity sent out MWh Load factor per cent Thermal efficiency per cent
1946 522 34.2
1954 7500 518 1,232 31.7
1955 5680 518 1,406 47.8
1956 5480 518 1,219 42.9
1957 5959 518 560 18.1
1958 4119 500 248 11.6
1961 250 256 11.7 27.9
1962 250 89 4.1 26.73
1963 250 193 5.43 26.24

The electricity 'sent out' data is the total output from both the hydro-electric and diesel plants. The proportions of diesel to hydro-electric generation was typically:

Year Hydro-electric kWh Diesel kWh
1946 256,440 270,512
1963 74,000 119,000

The operating conditions and electricity output of Machynlleth B power station were:[4] [6] [8]

Machynlleth B power station operating parameters 1957–72
Year Running hours Plant capacity kW Electricity sent out MWh Load factor per cent Thermal efficiency per cent
1957 184 3990 200 27.2
1958 1036 3990 2,146 49.0
1961 4258 6,310 16.9 33.79
1962 4258 10,386 27.8 35.33
1963 4258 13,712 36.83 34.9
1967 3990 14,843 41.5 35.03
1972 3990 4,077 11.6 31.18

See also edit

References edit

  1. ^ "Powys County Council records" (PDF). powys.gov.uk. Retrieved 28 October 2020.
  2. ^ Electricity CommissionerS (1938). Electricity Commissioners Eighteenth Annual Report 1 April 1937– 31 March 1938. London: HMSO. p. 106.
  3. ^ Electricity Council (1987). Electricity supply in the United Kingdom: a Chronology. London: Electricity Council. pp. 60, 69, 76. ISBN 085188105X.
  4. ^ a b c d e f g h Garrett, Frederick C. (1959). Garcke's Manual of Electricity Supply vol. 56. London: Electrical Press. pp. A-74, A-143.
  5. ^ Neither station is in the CEGB Statistical Yearbook for 1978
  6. ^ a b CEGB Annual report and Accounts, 1961, 1962 & 1963
  7. ^ Electricity Commissioners (1947). Generation of Electricity in Great Britain year ended 31 December 1946. London: HMSO. p. 11.
  8. ^ CEGB Statistical Yearbook 1972 CEGB p. 16-17