Randall water fall, Brong Ahafo Region

As part of its mandate to promote the commercialization of renewable energy resources in Ghana, the Energy Foundation has updated all the information on the well-known mini-hydro power generation sites in the country. The aim of the study was to bring to the notice of the government and potential investors, all available information on potential Mini Hydro Sites in the country reviewed under the present climatic, regulatory and economic conditions.

Some of the main findings are:

1. The villages located within a reasonable distance to justify the development of the identified sites for rural electrification are either grid connected today or at least within a distance of a few kilometers from the grid. Consequently the justification to develop the sites for rural electrification has been weakened considerably.

2. Comparing recently observed flow data with data from the 1960s and 1970s, it has been noticed that flows have considerably decreased in the last decade to the extent that some of the rivers completely dry out for up to 7 months a year. This is the result of massive deforestation in the catchment areas of the rivers. Run offs after rains are heavy and flow sustainability is non-existent due to the absence of forest cover.

3. The Likpe Kukurantumi site, where construction started in 1984, but was not completed, has been reviewed. The village is now connected to the grid for several years now and the equipment purchased from India is almost rotten.

4. As a result of the present reach of the national grid, many of the sites would have to be developed as grid connected plants. This however requires that the Government of Ghana through the Energy Commission and the Public Utilities Regulatory Commission (PURC) provides a clear regulation and attractive price for power supply into the national electricity grid.

5. The economic calculations show that with a power purchase tariff of around US$ 0.08/kWh high height sites such as the Randall and Fuller water falls located in the Brong Ahafo region and the Tsatsadu Falls in the Volta Region, might be economically sustainable. However more recent flow data would have to be collected for a detailed economical analysis as part of detailed feasibility studies for particular sites.

6. The low height sites, most of them in the Volta Region, would only be worth considering as integrated power and irrigation infrastructure. In that case, it should be considered to include a mini hydropower plant to provide power to pump the water to the farms and supply the excess energy to the national grid.

7. The Ghana Water Company is advised to systematically review the potential for Mini Hydro Plants on their dams and weirs, taking into consideration the recent flow data as well as the present power tariffs they have to pay.

8. Realistically, the quite modest mini hydropower potential in Ghana cannot make a considerable contribution to the national power requirement. This is not only due to the limited number of sites with reasonably high heads, but also due to the extremely unfavorable flow duration curves with a long dry season and high variations in river flows.