Determining the Optimum Scheme Layout for the Sombwe Hydropower Project

Determining the Optimum Scheme Layout for the Sombwe Hydropower Project

Author: Edwin Lillie, Robert Greyling
Conference: Hydro 2018
Date: October 15-17, 2018

INTRODUCTION
Legislation in the DRC has recently changed to allow Independent Power Producers (IPP) to compete in the local power market. To this end, Kipay Investments appointed Knight Piésold and Ingerop Consulting Engineers to conduct a feasibility study for the proposed Sombwe Hydropower Project in late 2016. The project is located approximately 290 km north of Lubumbashi in the Katanga Province of the DRC, shown schematically in Figure 1. Two existing hydropower stations have been operating for many years upstream of the proposed Sombwe site. The 71 MW Mwadingusha hydropower plant at the Tshangalele Dam and the 36 MW Koni hydropower plant, which is located immediately downstream of Mwadingusha.

The catchment area at Sombwe is approximately 47 337 km2 and is characterised by two main sub-catchments. The Koni sub-catchment, with an area of approximately 12 877 km2 upstream of Koni Hydropower Station and the Sombwe dam incremental catchment downstream of Koni, having an area of approximately 34 450 km2. The Tshangalele Dam regulates the river flow from the Koni sub-catchment, whereas river flow in the Sombwe dam incremental catchment is unregulated. Based on available statistics of the existing upstream HPP schemes, and considering that the Sombwe site drains a significantly larger catchment, the applicable range for installed capacity is expected to lie between 80 MW and 160 MW.

It was initially envisaged that a dam with a final height of 70m to 100m would be required at Sombwe to provide sufficient head and yield for the power generation. However, as it is a Greenfield project, a number of different scheme layouts were investigated to select the most appropriate configuration for the feasibility study investigation.

To select the optimum scheme layout and component sizes, several parameters were considered before focusing the feasibility investigation on the selected option. The key output required from the options analyses study was
to determine;

  • Dam site and type,
  • Dam height,
  • Power plant capacity,
  • A single dam or a combination of dams in a cascade,
  • A surface or an underground powerhouse,
  • The initial estimated capital and operating cost estimates in sufficient detail to select a preferred option,
  • The long term average energy yield, and
  • The levelised cost of energy for all the plausible options.

There are too many parameters to optimise a scheme in a single analysis and a logical stepwise approach was undertaken to eliminate some parameters early on, but to retain those which may still influence the optimum scheme selection, until a decision could be made on the most economical solution. The objective was to select the most economical option for investigation at the feasibility level of detail with due consideration of technical, economic, environmental and social conditions.

 

Download the full technical paper.

Download

Recent Insights

November 2021
Knight Piésold's Projects Commended at Prestigious Awards
November 2021
Engineer of Record Services for Tailings Facilities
November 2021
Gearing Up for Growth in Zambia
October 2021
Knight Piésold, aliado de la minería sustentable
September 2021
Knight Piésold Chile enfoque personalizado e integral de trabajo al estilo boutique
September 2021
Company Uses Innovative Ideas in Municipal Project
August 2021
South Africa Must Focus on STEM Skills to Enable Development
July 2021
Business Success Stories: Knight Piésold
July 2021
Holistic Approach to Mine and Industrial Water Management
July 2021
Selection of Undrained Shear Strength Parameters of Residual Soils and their Application in Stability Analysis
June 2021
Knight Piésold Focused on Africa's Infrastructure Development
June 2021
Century-old Knight Piésold Remains Committed to Clients and Communities in Phalaborwa
May 2021
Very Few Consulting Firms Reach 100 Years – Knight Piésold Celebrates with Optimism
April 2021
Knight Piésold Celebrates 100 Years of Excellence in Africa
April 2021
Video: Knight Piésold Celebrates 100 Years of Engineering Excellence
April 2021
Opportunities Abound to Support Africa's Resilient Growth - Knight Pièsold
April 2021
Firm Expands Service Offering
March 2021
Celebrating 100 Years of Engineering Excellence
February 2021
Improved Tailings Disposal Could Reduce Water Use
January 2021
Your Community, Your Neighbour