- Lethabo Power Station
Lethabo Power Station in the Free State,
South Africa , is a largecoal fired power station owned and operated byEskom .General
The Tswana word "lethabo", chosen as the power station’s name, means "good living, happiness". It symbolises the substantial contribution Eskom makes towards industrial, commercial and social life in South Africa.
History
Construction of the "power giant of the Vaal Triangle" started in 1980. The first of its 6 X 618 MW generating sets went into commercial operation in December of 1985. During site clearing, 190 000 Bluegum trees had to be removed, resulting in a significant rise in the underground water table. In addition, because the station had to be built on an area of heaving soils prevalent in the Free State, a very sophisticated piling foundation system for all major structures was required. The foundations were constructed on a total of 11 000 piles sunk at depths of up to 25m. A 750mm void was left under the foundations to allow for expansion and contraction of the underlying soil. The station went fully operational in December of 1990.
Location
Lethabo is located in the Free State near Viljoensdrift, at coord|26|44|31|S|27|58|39|E|display=inline,title. The 3 closest major towns are Vereeniging and Vanderbijlpark in Gauteng and Sasolburg in the Free State. This area is also collectively known as the Vaal Triangle.
Interesting Facts
* Lethabo holds the distinction of being the only power station in the world capable of burning coal with an average calorific value of only 16 MJ/kg. The unusually low quality of the coal means that it also has a very high ash content, ranging between 35% and 42%. At full load, the station consumes approximately 40 000 tons of coal per day, at the same time producing close to 16 000 tons of ash.
* It has 2 smoke stacks that are each 275 m tall. Each stack contains 3 individual flue gas ducts (one per boiler) that are visible as 3 discreet ducts near the top of the stack. At the time of construction, these smoke stacks were the 3rd tallest freestanding structure in South Africa. Access to the top is via a open mesh grating staircase or a rack-and-pinion crawler passenger lift travelling on a rail (rack) attached to the inside wall of each stack.
* Fly ash that were removed from Lethabo's flue gas streams were used extensively in the construction of the Katse Dam in Lesotho. [ [http://www.vaaltriangleinfo.co.za/vaal_triangle/industries/lethabo_powerstation.htm Lethabo Power Station ] ]
* The 6 boilers at Lethabo are each housed in a building as high as 35 storeys. [http://www.eskom.co.za/live/content.php?Item_ID=148&Revision=en/4 Eskom ] ]
* The turbine hall housing the 6 turbine - generators is 500m long.
* The 6 cooling towers are each 164 m high, as high as a 54 story office block.
* The white plume on top of the cooling towers is pure water vapour (not pollution).
* The station is a zero effluent loss power station.
* The ash dumps gets rehabilitated into “mountains”, covered with soil and grass.
Technical details
* Six 618 MW units Installed
* Capacity: 3708 MW
* Daily Coal Consumption - 40 000 TonsReferences
* [http://www.eskom.co.za/education/visit/lethabo/lethabo_offers.htm Lethabo Power Station Details]
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