Vinnie Naidoo Technical Executive GIBB (Pty) Limited South Africa

Transcription

1 Vinnie Naidoo Technical Executive GIBB (Pty) Limited South Africa

2 Structure of Presentation Outline of the Project Development Phases Key Attributes of the Project Environmental Considerations Scheme Layout Key Contracts and Suppliers Key Milestones Achieved

3 Acknowledgements Eskom Holdings SOC Limited - permission to print the paper Braamhoek Consultants Joint Venture Partners

4 Project Location 23 km NE of van Reenen s Pass

5 Pumped Storage Hydro Electric Power Generation Stores energy in the form of water in a upper reservoir At times of high electricity demand water is released to a lower elevation reservoir through a turbine/generator to produce electricity During times of low electricity demand the water is then pumped back to the upper reservoir to store energy

6 Background Long term planning Eskom and NER identified a need for enhanced peak generation capacity to serve: Growth in the Industrial Sector Successful Rural Electrification Programme Eskom initiated a study on appropriate sites for a PSS in the early 1980 s. Initially more that 90 appropriate sites were investigated 3 sites were shortlisted Assessed on Environmental, Social, Technical and Commercial criteria

7 Stages of Development In 1998 IPSS recommended for study at feasibility level Study undertaken by Eskom s own Hydro and Water Dept. and was completed in November 2003 Feasibility Report suggested an installed capacity of 1 000MW, and After subsequent optimisation studies the installed capacity was increased to 1 332MW September 2003 interested parties invited to bid to provide consulting services for Detailed Design

8 Stages of Design Phase 1: Project Optimization Geotechnical Investigations Surface Works Geotechnical Investigations Underground Works Exploratory Tunnel Phase 2: Final Design, Tender Design Access and Site Roads Site Infrastructure Upper and Lower Dams Underground Works Hydro-mechanical & Electrical Works (Performance Specification)

9 Stages of Design (cont.) Phase 3: Construction Stage Design, Monitoring, Supervision and Sign-off Verification of Design Assumptions Foundation Interfaces and Design Rock Interface and Site Influenced Design Hydro-mechanical and Electrical Interfaces Construction Drawings Construction Supervision Record Drawings Project Sign Off

10 Record of Decision (RoD) Issued by the Minister of Environmental Affairs and Tourism (13 December 2002)

11 Conditions of RoD Key conditions of the RoD: An Environmental Management Plan (EMP) shall be developed and its recommendations implemented A bypass system shall be provided to maintain the natural seasonal flows in the water courses at the upper reservoir No loss of the wetland due to flooding from the upper reservoir There shall be no negative impact on the wetland downstream of the upper reservoir A new cliff shall be provided for the colony of Bald Ibis to roost and nest

12 Conditions of RoD (Cont.) Key conditions of the RoD (cont): Any new quarries must be below the minimum water level The construction spoil shall be disposed of below the minimum water level The upper dam must blend in with its natural surroundings A low weir shall be built downstream of the upper dam to distribute the water across the wetland A baseline study shall be carried out for the wetland

13 Scheme Characteristics Rated generating capacity MW Energy Storage Capacity of MWh or 15.8 generating hours Minimum full load generation reserve of 4 hours (maintained throughout each weekly cycle)

14 Weekly Operating Cycle

15 Scheme Layout Options Option 4 Option 2 Option 3 Option 1 Single LPHT Single TT Single LPHT Emergency Gates in SS Twin HPHT Single TT Twin System Two separate hydraulic systems Twin LPHT & HPHT Single TT

16 Cost (30%) Construction Period (15%) Operational Flexibility (15%) Maintenance (15%) System Efficiency (15%) Environmental Impact (10%) Final Scheme Layout Selection Weighted Multi-Criteria Assessment

17 Scheme Components Upper Reservoir Intake Structure Surge Shafts Underground Powerhouse Outlet Structure Lower Reservoir

18 Upper and Lower Reservoirs 22 million cubic meters capacity 4,6 km apart Elevation difference approx 470 m Upper Reservoir (Bedford Dam) Concrete faced rockfill dam 810m long, 50m high, 100m long spillway, 8m crest width Lower Reservoir (Braamhoek Dam) Roller Compacted Concrete dam Length 331m, crest width 5m Spillway 39 m high, 40 m long crest

19 Hydraulic System Layout

20 Tunnels and Waterways About 13km of tunnels Some for access and cables Majority for waterways Low Pressure Headrace Tunnels 2 x 130m long circular reinforced concrete lined section, 6.6m dia. 2 x 900m long circular steel lined section, 5.1m dia. High Pressure Headrace Tunnels x 2, concrete and steel lined Draft Tubes x 4, concrete and steel lined Tailrace Tunnel x1, concrete lined

21 Powerhouse Layout

22 Powerhouse Layout (3D) Exploratory Tunnel Surge Chamber Access Tunnels Busbar Gallery

23 Powerhouse Machine Hall Cavern 27m wide, 184m long, depth 46m 4 reversible Francis type pump turbine / motor generators Largest cavern in the world in mud stone Transformer Hall 19m wide x 176m long, depth 14m 4 x Main unit transformers Ancillary E&M 2 x Static Frequency Converter Busbar Tunnels 4 x busbar galleries 7m x 7m cross section

24 Key Contracts and Suppliers The Client Eskom Holdings Limited Consultants Braamhoek Consultants Joint Venture (GIBB Lead Consultant, Knight Piesold and RHDHV) Acer (Africa) Environmental Consultant

25 Key Contracts and Suppliers (Cont.) Contractors Murray & Roberts - exploratory tunnel Grinaker-LTA - access roads CMI JV, comprising CMC di Ravenna, PG Mavundla and Impregilo - underground civil works Afriscan - water supply, sewage treatment, small access roads and building of temporary Eskom offices B&E Quanza Group - aggregate quarry

26 Key Contracts and Suppliers (Cont.) Contractors (Cont.) Braamhoek Dams JV, comprising Concor and WBHO upper and lower dam contracts Voith Siemens Hydro Power Generation electro mechanical equipment contract ABB - electrical balance of plant (ebop) solution.

27 Project Development Programme

28 Summary - Key Milestones Reached May 08 Dams Contracts awarded Sep 08 Main Hydro Mechanical Contracts awarded Apr 09 MUW Contract awarded Jun 09 Access Roads completed Sep 10 ebop Contract awarded Apr 11 Dams Contract completed Dec 11 Lower Dam at FSL an 12 Machine Hall Excavation Completed Aug 12 1st Draft Tube encased Feb 13 1st Spiral Case installed Mar 13 last Draft Tube encased Aug 13 last Spiral Case installed

29 Commercial Operation The first of four 333 MW pump turbine units at the project is expected to be commissioned in the second half of 2015, The remaining units to start commercial operation in 2015 and 2016.

30 THANK YOU Vinnie Naidoo GIBB (Pty) Ltd