NKULA POWER STATION

Nkula Power Stations, consisting of 2 independent power stations but sharing the same intake pondage are located in Southern Region of Malawi, in Nneno, and is the first of three cascaded power stations power on the Shire River owned and operated by ESCOM Limited. They were constructed to utilize the Nkula Falls.

Nkula A Power Station, the first power station in the country, came into being between 1966 and 1967. The Power Station is composed of 3 x 8MW English Electric machines driven by vertically installed Francis turbines. Nkula B Power Station is composed of 5 x 20MW Voith machines.

The salient features of the power plant are the head pond, intake structures, tunnels, surge chambers penstocks butterfly valves, generating machines and associated auxiliaries ancillary plant switch yard and the transmission line.

Problems facing Power Generation at Nkula

• Old Age: As already indicated, the plant at Nkula is very old consequently forced outages are numerous. This is so because the plant has not undergone thorough refurbishment as could have been expected worse still some of the spares are obsolete. Inability to carry out thorough and comprehensive refurbishment is due to two issues: monetary and capacity constraints.
  
• Capacity Constraints: The time currently given to maintenance of the machines is intended to keep the machines going and not to add value and extend their useful life. This is only done during weekends to avoid extended outages and load shedding.
  
• Monetary Constraint: For sometime ESCOM has been going through financial hardship. The results of this are inadequate maintenance funding and delayed project implementation such as modernization of the excitation and control systems for Nkula A and B.
  
• Environmental Issues:

i. Conflicting Government Policies and Encroachment: those advocating cultivation on the banks of rivers to take advantage of irrigation and those against. The result of this is encroachment and results in uncontrolled agricultural practices.

ii. The wanton cutting down of trees: for charcoal and brick making has left the land bare hence exposing the soil to erosion. The eroded soil ends up at the hydro power station intake dams. The soil covers up the dam and reduces the water storage capacity unless it is dredged.
The soil that passes through the machine erodes the water ways hence raising plant maintenance costs.

iii. Farming Practices and Aquatic Weeds: Erosion from gardens leach out fertilized into the rivers thereby providing rich nutrients for aquatic weeds. Money has to be expended to deal with the aquatic weeds.

iv. Siltation: As the first power station on the Shire River, Nkula Power Station gets the most brunt of every thing: weeds and silt. Scouring, one of the methods of silt removal from the intake can not (currently) be employed at Nkula due to capacity constraints. Consequently dredging is the only practical method currently being utilized.
A long term solution is to address environment degradation.

v. Inherited Design and Installation Problems: Nkula A intake can not be accessed for repairs without shutting down Nkula B Power station resulting in a big generation deficit. Consequently, modifications have to be made to improve performance of the plant.

vi. Misconceptions and Wrong Expectations of Local Communities: Local communities perceive ESCOM establishment as Government and expect free for all ESCOM Services (electricity, water, medical services, and transport).
Engagement in organized site visits and dialogue with local village heads is improving understanding between the communities.

vii. Wildlife
By cutting down trees in the surrounding area, monkeys have migrated to the trees left within the Nkula Power Station boundary. Hence the risk of interruption of power by monkeys.

Power Station Links:

| Kapichira | Nkula | Tedzani |