Littlebrook Power Station

Littlebrook Power Station
Littlebrook D power station Viewed from the south in March 2008
Country	England
Location	Kent, South East England
Coordinates	51°27′55″N 0°14′30″E / 51.465278°N 0.241667°E / 51.465278; 0.241667Coordinates: 51°27′55″N 0°14′30″E / 51.465278°N 0.241667°E / 51.465278; 0.241667
Commission date	1939
Decommission date	2015
Operator(s)	RWE npower
Thermal power station
Primary fuel	Oil-fired
grid reference TQ556764

Littlebrook Power Station refers to a series of four oil and coal-fired power stations situated on the south bank of the River Thames, next to the Queen Elizabeth 2 Bridge and the Dartford Tunnel in Dartford, Kent. The final power station, Littlebrook D, ceased operating in March 2015.

The first power station on the site was the coal-fired Littlebrook A Power Station, built by the Kent Electric Power Company in the early 1930s. It was opened in 1939. Coal was initially brought to the station by rail, until a riverside pier was completed. The station was later converted to burn supplementary oil over coal, and remained in use until it closed in 1973. The 'Station had six coal-fired boilers, 3 chain grate and 3 pulverised fuel. The steam raised in the boilers was fed to three steam receivers which in turn supplied three steam turbine generators. Two of the turbines were supplied by CA Parsons at 30 MW each driving a directly coupled air cooled alternator running at 3000 rpm. The third turbine was supplied by BTH running at 1500 rpm driving a 4-pole air cooled alternator. In its last years the 1500 4 pole alternator was decoupled from its turbine and used as a synchronous compensator thereby providing voltage regulation to its local grid.

The construction of Littlebrook B Power Station was delayed by the Second World War, and came into use between 1949 and 1950. Like the A Station, it originally burned coal, but was later converted to burn oil instead. It had a capacity of 120 MW and remained in use until 1975. This 'Station featured several new concepts in power generation design; it incorporated the "unit concept" whereby boilers directly supply steam to its designated turbine-generator. (Previously boilers "pooled" steam via a range or receivers to any of the installed turbines). The steam cycle featured "reheat" where steam exhausting from the initial high-pressure turbine cylinder is routed back through the boiler to be reheated thereby increasing its available energy before being returned to the turbine's intermediate cylinder. Finally the 60 MW Alternator was cooled by pure hydrogen gas which has a far greater cooling effect than air. These features became common in later power station designs utilising turbine generators rated at 120 MW and over.