No large African lake supplies electricity to Ghana. Instead, Ghana's hydroelectric power comes primarily from the Volta River system.
These dams provide the majority of Ghana's electricity, supplemented by thermal plants (natural gas, light crude) and growing solar capacity. Lake Volta is a reservoir, not a natural lake, and lies entirely within Ghana—not shared internationally like Lake Victoria or Lake Tanganyika.
Ghana also exports power to neighbors (Togo, Benin, Burkina Faso) via the West African Power Pool.