TANESCO’s generation system consists of hydro, thermal and gas.  Hydro contributes the lion’s share of TANESCO’s power generation.  The total generation from TANESCO own sources in 2003 was 2,662,027,682 kWh out of which 2,551,416,842 is from hydro power stations.

TANESCO operates an interconnected grid system comprising of hydropower generating stations.  The installed capacity are: Kidatu 204 MW; Kihansi 180 MW; Mtera 80 MW; Pangani 68 MW; Hale 21 MW; and Nyumba ya Mungu 8 MW totaling to 561 MW of hydro generation.

There are several diesel generating stations connected to the national grid in Dar es Salaam, Mwanza, Tabora, Dodoma, Musoma and Mbeya.  These have installed capacity of 80 MW but they effectively contribute about 35 MW due to running problems.  Some regions, districts and townships are dependent on isolated diesel – run generators (Kigoma, Mtwara, Lindi, Njombe, Mafia, Mpanda, Tunduru, Songea, Liwale, Ikwiriri, Masasi and Kilwa Masoko).  These have installed capacity of 31 MW but they effectively contribute about 15 MW due to aged machinery and lack of spare parts.

Two private independent power projects (IPP’s) which are connected to TANESCO grid are IPTL (Independent Power Tanzania Ltd) with 100 MW installed capacity and SONGAS (Songo Songo gas – to electricity project) which by the end of 2004 had 120 MW capacity although more gas turbines will be installed to increase the capacity to 200 MW before the end of year 2005.  TANESCO also imports 10 MW of electric power for Kagera Region from Masaka substation in Uganda while Sumbawanga, Tunduma and Mbozi districts receive about 3 MW from neighbouring Zambia.  Bulk supply of electricity is made to Zanzibar from Ras Kilomoni substation at the Indian Ocean coast in Dar es Salaam.