The Siti I SHP is a run-of-river plant with an installed capacity of 6.1 MW and estimated 29 GWh annual production, located in Bukwo District, Eastern Uganda. The Project secured investments of USD 14.8M, with USD 3.6M in GET FiT commitments. The Project has the longest waterway in the GET FiT portfolio at more than 5 km in length, comprising a short section of canal, nearly 3 km of headrace pipeline, and 2 km of penstock.
Construction commenced in March 2015 and concluded in March 2017, with the power station synchronised and evacuating power to the grid by April 2017 – the first GET FiT hydropower project to achieve commercial operation. However, due to issues with respect to the stability and quality of the power evacuation line, the Project was only able to evacuate power to the grid at between 2-3 MW. Improvements to the power evacuation infrastructure were subsequently implemented during October 2017, allowing the Project to evacuate power to the grid at full capacity. However, as evident in Figure 1 and 2 below, substantial grid outages continued throughout October and November and, to a lesser extent, December, with outages in December being partly attributable to planned grid maintenance activities.
Grid failures and outages amounted to more than 127 days since achieving commercial operation and were approximately equivalent to more than 53% of actual production, which is excessively high. The new 33 kV power evacuation line between the Project and Kapchorwa, and the existing line from Kapchorwa, experienced extensive faults. UETCL has since upgraded the line in sections and in September the line was able to hold the performance tests by the Project at 5 MW. The grid outages have gradually reduced, with the lowest outages experienced thus far occurring in December. Nevertheless, further improvements to the evacuation infrastructure are required to minimise outages and the potential for further deemed energy claims.
By the end of 2017, the Project had delivered 11.4 GWh of energy to the grid during its 8 first months of operations. An estimated 6.1 GWh could not be produced due to grid failures and outages out of the plant operator’s control (deemed energy). Without these losses, the cumulative energy output would have been 17.5 GWh, based on available water and the plant’s overall performance(2). This is approximately 75% of the average production estimated at GET FiT application stage for the same 8 month period, indicating that flows during the production period were less than estimated. It is, however, too early to conclude if the energy production estimates are overly optimistic based on less than one year of production data and without any available analysis of the regional hydrology for 2017.
Figure 1 – Siti I SHP actual versus estimated energy output.
Generation data shown from the first full month of operation – May 2017
Figure 2 – Siti I SHP – plant versus grid availability
(2) The plant availability for the same 8 month period was on average 97.3%, which is considered good performance for the first year of operation.