Ingula Pumped Storage Scheme

Ingula Pumped Storage Scheme

Client
ESKOM

Location
Free State and KwaZulu-Natal, South Africa

Highlights
  • 19th largest pumped storage scheme in the world
  • Power station located 350 m underground (116 storeys)
  • Machine Hall Cavern: largest excavated in mudrock in the world (183 m x 26 m x 55 m)
  • Material excavated: 3 million m3
  • Steel lining installed for waterways: 15,000 tonnes
  • Tunnelling: more than 10 km
  • Operating head range: 460-480 m
  • Generating flow rate: 350 m3/s
  • Pump rate: 241 m3/s
  • Energy storage: 21,000 MWh (15.8 generating hours)
  • Job opportunities created: 3,000
Project Overview

The Ingula Pumped Storage Scheme is an impressive 1,333 MW hydropower scheme, designed to augment the National Grid during peak power usage periods. This engineering innovation was a design created by a three-way joint venture among Knight Piésold, Royal HaskoningDHV, and GIBB (Pty) Ltd. The scheme is characterized by a lower reservoir (Bramhoek Dam), an upper reservoir (Bedford Dam), waterway tunnels, four 333 MW Francis pump turbines, an access tunnel, and a powerhouse cavern.

Project Role

Knight Piésold assisted with the geotechnical investigations, tender design, procurement, detailed engineering, and construction and commissioning supervision.

Engineering services were provided in three phases:

Phase 1: Project Optimization

  • Geotechnical investigations – surface works
  • Geotechnical investigations – underground works
  • Exploratory tunnel

Phase 2: Tender Design

  • Access and site roads
  • Site infrastructure
  • Upper and lower dams
  • Underground works
  • Hydromechanical and electrical works (performance specification)

Phase 3: Construction Stage Design, Monitoring, Supervision, and Sign-off

  • Verification of design assumptions
  • Foundation interfaces and design
  • Rock interface and site influenced design
  • Hydromechanical and electrical interfaces
  • Construction drawings
  • Construction supervision
  • Record drawings
  • Project sign-off
Awards
  • South African Institution of Civil Engineering: SAICE Awards 2016, Winner in Technical Excellence Projects Category, Ingula Pumped Storage Scheme, Braamhoek Consultants Joint Venture (Knight Piésold, Royal HaskoningDHV, GIBB)
  • South African Institution of Civil Engineering: SAICE Awards 2016, Winner in Water Engineering Projects Category, Ingula Pumped Storage Scheme, Braamhoek Consultants Joint Venture (Knight Piésold, Royal HaskoningDHV, GIBB)
  • Consulting Engineers South Africa: 2016 Excellence Awards, Winner in "Projects with a value in excess of R250 million" Category, Ingula Pumped Storage Scheme, Braamhoek Consultants Joint Venture (Knight Piésold, Royal Haskoning DHV, GIBB)
  • South African Institution of Civil Engineering: 2012 SAICE Annual Awards, Outstanding Civil Engineering Achievements Award in the Water Engineering Category, Ingula Pumped Storage Scheme, Bedford Dam (Braamhoek Consultants Joint Venture: GIBB, SSI, and Knight Piésold)
  • Consulting Engineers South Africa: 2011 AON Engineering Excellence Awards, Winner in “Project with a value between R250 million and more” Category, Ingula Pumped Storage Scheme, Bedford Dam (Braamhoek Consultants Joint Venture: GIBB, SSI, and Knight Piésold)