Geothermal Development in Tanzania – A Country Update

Abstract

Tanzania is endowed with a huge geothermal potential which has not yet been used, and has only been explored to a limited extend. Geothermal power is a reliable, low-cost, environmental friendly, alternative energy supply and an indigenous, renewable energy source, suitable for electricity generation.

The total installation capacity is 1320 MW using hydro, gas and thermal. Currently, the national power system mostly relies on hydropower. A long period of drought between 2003 and 2006 as well as 2009 and 2010 lead to shortfalls in electricity supply from the hydropower stations; thus, the government of Tanzania intends to diversify the country’s energy mix and is looking for alternative sources of energy. The country power generation potential consists of hydro power, Heavy Fuel Oil (HFO), coal, wind energy, solar, sea waves, natural gas, geothermal and biomass. Most of the geothermal sites already identified with hot springs are located in areas transacted by the East African Rift System. Such areas include the northern volcanic provinces of Kilimanjaro, Meru and Ngorongoro and the Rungwe Volcanic Province in southwest Tanzania. In addition, some coastal areas also show surface manifestations of geothermal resources.

In Tanzania, several reconnaissance surveys and a few detailed studies of hot springs and geothermal sites have been carried out since 1949; some of these early studies in geothermal sites included measurements of surface temperature, water and gas flow as well as water and gas analyses of the hot springs. These studies on geothermal energy provide basic information for planning current geothermal projects. In 2006 and 2007, the Ministry of Energy and Minerals (MEM); the Division of Energy in collaboration with the Geological Survey Tanzania (GST) and the Federal Institute for Geosciences and Natural Resources (BGR) of Germany carried out geological, geochemical and geophysical investigations to assess the geothermal prospects as well as to locate a hydrothermal system and potential geothermal reservoirs. The results from the electromagnetic surveys (TEM, MT) conducted, show zones of low resistivity in the Ngozi area, which can possibly be correlated to alteration zones caused by geothermal activity and in turn indicate a potential geothermal reservoir (GEOTHERM, 2006). Further geophysical work was done in 2010 as a continuation of GEOTHERM. 2006.