Simson Haulofu Divisional Manager. NamPower Namibia

Transcription

1 Simson Haulofu Divisional Manager NamPower Namibia

2 Agenda Overview of Ruacana Some interesting facts about Ruacana Ruacana s contribution to Namibia Ruacana operating regime Unit 4: Business case & feasibility study Unit 4: Contracting and scope of work Unit 4: Milestone dates & project issues Technical discussions and comparisons

3 Overview of Ruacana(1 of 3)

4 Overview of Ruacana(2 of 3)

5

6 Overview of Ruacana(3 of 3) Five essential components that constituted the original construction of Ruacana: Gove Dam was constructed ± 430km upstream of Ruacana and was commissioned in Calueque Dam was constructed ± 65 km upstream of Ruacana. Ruacana diversion weir located ± 1.5 km upstream from Ruacana in Angola. The power plant which comprises three Francis turbines generates a total of 240MW. The construction of a 570km long 330 kv transmission lines in 1977.

7 Some interesting facts about Ruacana A total of m 3 of rock was excavated. Units 1,2,3 were commissioned in 1978 but power generation was not possible. In 2003 Ruacana became the first hydropower facility in the world to adopt Profibus technology. Ruacana is the core of NamPower s power generation.

8 Ruacana s contribution to Namibia

9 Operating regime (1of 2) Wet season During the months from Dec-July, the power station is operated as a base load. Change of season: During August and September, the power station is operated as a mid-merit Dry season: During October and November Ruacana operated as a peaking station(6am to 9am)and(6pm to 9pm) depending on weir level

10 Operating regime (2 of 2) MWh :0001:0002:0003:0004:0005:0006:0007:0008:0009:0010:0011:0012:0013:0014:0015:0016:0017:0018:0019:0020:0021:0022:0023:00 Time of day Wet season Mid season Dry season

11 Business case for Unit 4 During the last years the average national load has increased beyond 320MW. The old Van Eck power station is not run at full capacity. Aggravated by the electricity shortage in Southern Africa. As well as the nature of the Eskom system characterized by mainly large coal fired power stations. Accessibility to peak power is always be beneficial.

12 Feasibility study for Unit 4 The following elements were considered in the study: Economic analysis Impact on NamPower s corporate bank model Transmission integration study Waterway verification study Environmental considerations Ruacana 4 th unit motivation as a peaking station. As such, a decision was taken in October 2007 to commence with the project.

13 Unit 4: Contracting and scope of work (1 of 7)

14 Unit 4: Contracting and scope of work (2 of 7) Turbine-Generator contract FIDIC yellow book plant design and build Alstom and Andritz as the consortium contractor with Norplan as the Engineer

15 Unit 4: Contracting and scope of work (3 of 7) Scope of work Andritz: Penstock piping Spiral casing Penstock inlet valve Turbine runner Cooling water system and auxiliaries for turbine. Alstom: Generator Excitation and Interconnection systems Unit control & protection 380V AC and 220V DC systems

16 Unit 4: Contracting and scope of work (4 of 7) Civil contract [2 Milestones] FIDIC red book construction Civil contractor with NamPower/Norplan as the Engineer

17 Unit 4: Contracting and scope of work (5 of 7) Scope of Work: Milestone 1 Warehouse Labourer s camps Ablution and sewerage facilities Mess hall and catering Milestone 2 Concreting of the Penstock and spiral casing

18 Unit 4: Contracting and scope of work (6 of 7) 330kV GIS Switchgear and GSU transformer contract FIDIC yellow book plant design and build NamPower as the Engineer

19 Unit 4: Contracting and scope of work (7 of 7) Scope of Work Siemens ABB The addition of the 330kV Gas Insulated Switchgear The supply and installation of the 105 MVA generator step up transformer

20 Unit 4: Technical specifications and comparisons Penstock The new and existing penstock are both 130.5m long and 3.6m diameter. Turbine Existing turbines: Normal speed of 230.1rpm, 68m3/s flow with a runaway speed of 419rpm New Turbine: Normal speed of 272rpm, 71m3/s flow with a runaway speed of 480rpm

21 Unit 4: Technical specifications and comparisons cont d Generator Existing generators: 88.8MVA, 85MW, 0.96pf, 11kV, 4665A New generator: 105MVA, 92MW, 0.86pf, 11kV, 5511A

22 Copyright Unit 4: Penstock lower bend

23 Copyright Unit 4: Penstock upper bend

24 Unit 4: Lesson s learnt on Turbine-Generator The original power plant was built over 30 years ago: challenge integrating new and old technology safety standards have also changed Suppliers have standard solution-difficulty in integrating the different technologies from different suppliers. With same head, the new machine will have a higher output.

25 Unit 4: Lesson s learnt on Civil contract The civil works includes 2 milestones: Warehouse & Site accommodation /Canteen Milestone 1 Powerhouse Milestone 2 This presents a mixed Scope of Work highly technical vs more simple. Complicated soil conditions due to soil tip of original site. Bill of Quantity should have included weekly P&Gs.

26 Unit 4: Project progress Civil works Milestone 1 Accommodation camp is complete The mess and canteen facilities is ready for use The warehouse steel structure is constructed and work is on going. Milestone 2 Penstock shaft investigation done Preparatory cleaning of the shaft is completed Concreting of the lower bend steps

27

28

29

30 Unit 4: Project progress cont d Electrical works Basic design almost completed and detail design is on-going. Orders of IPB, control system, stator bars, stator frame & rotor spider have been placed. Factory Acceptance Test for the first part of control system equipment and stator frame is complete.

31 Unit 4: Project progress cont d Mechanical works The mechanical contractor, has mobilized since 17 June. Penstock cans were manufactured in Dorbyl-Newcastle, RSA and have been delivered to site. Final control and adjustments of the runner is being done. Wicket gates are machined and NDT tests are ongoing. PIV parts have been machined and are in the workshop. Turbine shaft seal and guide bearing support ordered from Aratz (Spain). Spiral casing FAT is complete

32

33

34

35

36

37

38 Unit 4: Milestone dates Commencement Date Elec-Mech 27 Mar 2009 Commencement Date Civil 30 Sep 2009 Start Civil Works 28 Oct 2009 Civil Works [M1] complete 20 Aug 2010 Start Mechanical Works 17 Aug 2010 Civil Works [M2] complete 05 Oct 2011 Completion Elec-Mech Works 27 Mar 2012

39 Thank you