Modelling of hydropower systems of Ghana at low level conditions of Akosombo dam

This paper presents a model of Hydropower systems in Ghana. It deals with conditions when the water level of the Akosombo dam is low. There are two hydropower plants in Ghana located at Akosombo and Kpong. The two plants are along Volta River with the Akosombo plant upstream of the Kpong plant. Thus, the discharge from the upstream plant creates the head for the downstream plant. The Akosombo plant is designed to operate at a minimum level of 75.59m (248ft). It has, on a number of occasions, recorded low elevation in the dam (i.e. below75.59m). At the low level conditions, the two plants are mostly coupled than independently run. A model has been developed within these low elevation conditions. It was found that with average efficiencies of 84.5% and 93.5% at Akosombo and Kpong plants respectively, the model fits the system. Journal of Science and Technology Vol. 25(2) 2005: 131-13