Lethabo Power Station in the Free State, South Africa, is a large coal fired power station owned and operated by Eskom.Power generationThe station consists of six 618MW units for a total installed capacity of 3,708MW. Total efficiency at Turbine Maximum Continuous Rating is 37.80%Lethabo Power Station LETHABO POWER STATIONLocation: Between Vereeniging and Sasolburg in the Free State.Employees: Approximately 1 100Technical details:•Six 618MW units •Installed capacity: 3 708MW •2001 capacity: 3558MW •Design efficiency at rated turbine MCR (%): 37.80% •Ramp rate: 33.33% per hour •Average availability over last 3 years: 93.05% •Average production over last 3 years: 21 572GWhHistory: Construction of Lethabo started in 1980 and by December 1990, the station was fully operational. The station has been built on 11 000 concrete piles which were sunk 25 metres deep. The reason being to alleviate the heaving clay problem after some 190 000 bluegum trees were removed during site clearing. At the time, it was the largest piling contract ever awarded to a South African contractor.General: Lethabo burns coal with a calorific value of 15 - 16 MJ/kg and an ash content of 42%. It is the only power station in the world running on such low grade coal.