Optimal scheduling of hydropower development projects in Tanzania.

Although Tanzania is a country which possesses a sizeable potential of HP, only a very small part of this potential has so far been developed, and electricity in general still accounts for a very minute part in the country's total energy consumption. This is mainly due to the fact that it is very expensive to develop HP sources and transmit the energy to consumers for such a considerably vast country. Though capital intensive as compared to other sources of electricity and energy in general, HP Projects are usually accompanied with advantageous factors which make them the most preferable sources of electricity. The factors include the facts that HP projects are characterized by high rates of return, they are almost pollution free, and the water is renewable, ie. available for other uses after electricity generation. But Tanzania being a poor developing country, the technical and financial capability to develop the existing HP potential sources is very minimal. As a result, this calls for a need to plan properly the order in which these sources should be developed, so that the limited inputs can be used in the most economical and beneficial way. Thus this study aims at scheduling the feasible HP sources for development and construction in such a way that the Electrical Power demand in the country will be met in the most economical and optimal way. In this study, one of the widely used optimization methods, i.e Dynamic Programming is applied in the scheduling of selected HP schemes. The author first describes a model that provides estimates of Annual Electrical Energy from the schemes and this model is then applied in the Dynamic Programming method. Although the procedure is quite tedious, the results are quite promising. A short term plan, giving a schedule to meet the Electrical Energy Demand in the country for the coming 20 years, has been proposed. In the Plan, out of the studied 16 Projects, 10 Projects have been selected to provide the electrical energy demand up to the year 2015, whereby the then electrical energy demand is estimated (from 10% p.a growth of the present -1995 demand of 3132 GWH/year) to be 21,069 GWH/year, and for the long term plan all the 16 studied Projects are proposed. The Projects proposed in the short term Plan are Upper Kihansi, Kishanda, Lower Kihansi, Ruhudji, Masigira, Kakono, Rumakali, Stiegler's 1, Stiegler's 2, and Stiegler's 3 HP Projects. For the long term Plan, development of Shughuri and Kingenenas, Mpanga, Gingama, Iringa, Rusumo, and Igamba HP Projects, in addition to the Projects in the short term Plan, is proposed. Lastly, a few recommendations to help in solving the current capacity and generation problems are given. These include: (1) Efforts should be made to secure financial and technical assistance required to enable speedy implementation of the proposed generation schedule. (2) TANESCO should investigate the possibility of importing electricity from neighbouring countries. (3) Formation of adequately equipped Boards to manage, monitor and control the water sources ( ie. river basin) of the HP sites.