The Hale hydro electric Power Plant utilizes a natural fall of 70 metre some 40 river miles from Indian Ocean. It is sited at Hale Township on the Segera –Tanga highway, 6 km from the Tanga – Moshi junction at Segera.
The hydro works include a storage weir across the Pangani River, 4km upstream of a diversion intake weir. Intake works integral with the intake weir surmount a vertical drop shaft to a headrace tunnel which leads the water via a surge shaft and a high pressure shaft and tunnel to the turbines in an underground power station 76 metre below ground level. Water is returned to the river through a tailrace tunnel and open channel
The underground power station, with installed capacity of 21 MW, is formed by a cavern in the rock 30 metre long by 12 metre wide with a maximum excavated height of 24 metre. Power is generated by two vertical units comprising Francis turbines and salient pole generators.
The station is accessed by a shaft 6 metre in diameter which includes a stairway, lift, and space for cables and piping. The shaft is concrete sprayed with special provisions for drainage. Plans are there to access the station by an access tunnel.
The plant is scheduled to undergo major rehabilitation in the year 2009. The Project objective is to improve the overall operational and safety aspects for the operation and maintenance staff at the Plant and to improve the generation reliability of the Plant. The Project will also extend the remaining life time of the Plant and contribute to avoiding a power generation constraint in the country. The last rehabilitation works were carried out in the year 1987.