Ghana has ordered the Volta Aluminium Company (Valco) to temporarily close two of the five pot lines serving its smelter because of a fault at the Akosombo hydroelectric plant.

Energy Minister Albert Kan-Dapaah told parliament on Tuesday the closure would allow state-run power generating company Volta River Authority to save 150 megawatts for other users.

Valco's smelter in Tema, 18 km east of the capital Accra, has an annual production of 160,000 tonnes per year.

The minister did not say how long it would take to fix the fault at the dam.

Valco's parent company, Houston-based Kaiser Aluminium Corp (NYSE:KLU - news), filed for Chapter 11 bankruptcy last week but said the filing did not include the Valco smelter.

Pots are electrolytic cells arranged in lines and connected to a power source in which alumina, an intermediate raw material derived from bauxite, is reduced to aluminum metal.

Valco normally consumes about 60 percent of the power generated by the Akosombo dam and it is now negotiating with the Ghanaian government over how much it should pay for electricity.