feasibility study of the kafue gorge lower hydroelectric ... · feasibility study of the kafue...

Authored By

Manoj Bhattarai Nicola Saporiti Bruno TrouilleMWH, USA IFC, USA MWH, USA

Feasibility Study of the Kafue Gorge Lower Hydroelectric Project

Presented By

Bruno TrouilleMWH, USA

Janus BassonBKS (Pty) Ltd

Hydropower Africa 2010, August 18, 2010

IntroductionIntroduction

� Zambia Electricity Demand

� Export Electricity Demand

� Zambia and Southern Africa Power Pool Transmission

� Installed Capacity

� Zambia Least Cost Expansion

� Hydrology

� Site selection

� Geology

� Project Description

� Construction Schedule and Costs

LocationLocation

Demand Forecast AssumptionsDemand Forecast Assumptions

Zambia Electricity DemandZambia Electricity Demand

28,261

20,812

12,439

17,245

0

5,000

10,000

15,000

20,000

25,000

30,000

2005 2010 2015 2020 2025 2030

Year

GW

h

High Base

Low Adjusted Base

Total Zambian Electricity Demand Forecast


0

5,000

10,000

15,000

20,000

25,000

30,000

2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027 2028

Year

GW

h

Large Power Small Power Commercial ResidentialServices Existing Mining New Mining Load New Large Industrial

Total Zambian Electricity Demand Forecast for Adjusted Base Case


17,245

19,049

19,792

0

5,000

10,000

15,000

20,000

25,000

30,000

2005 2010 2015 2020 2025 2030

Year

GW

h

Total Zambian consumption Bulk supply Net Energy Generation

Total Zambian Electricity Demand Forecast for Adjusted Base Case


5,898

4,232

2,329

3,710

0

1,000

2,000

3,000

4,000

5,000

6,000

2005 2010 2015 2020 2025 2030

Year

MW

High Base

Low Adjusted Base

Total Zambian Peak Power Demand Forecast

Export Electricity DemandExport Electricity Demand

� Southern African Power Pool (SAPP)

� Potential export markets

� Namibia

� Malawi

� South Africa

� Zimbabwe

� Other neighboring countries also evaluated

Zambia and Southern Africa Power Pool TransmissionZambia and Southern Africa Power Pool Transmission

Zambia and Southern Africa Power Pool TransmissionZambia and Southern Africa Power Pool Transmission

� ZESCO owns 330-kV transmission network running as a

backbone form the South to the Northwestern part of the

country.

� 220-kV and 132-kV branches

� Southern African Power Pool (SAPP) upgrades

� Kafue town and Livingstone

� Livingstone to Katima Mulilo

� Katima Mulilo into the Namibian network

Installed Capacity StudyInstalled Capacity Study

Hourly loads observed in a typical week for the year 2007

were extrapolated to model the peak week for the years

2016 and 2025.

KGL as 100% base-load plant in 2016 (450 to 600 MW)

�Dispatch of 278 MW in 24 hours

�506 MW of peak power available for export (4 hours a day)

�57 MW of base-load power available for export

KGL as peaking plant in 2016 (600 to 900 MW)

�Base of 199 MW in 24 hours to a peak of 513 MW

�915 MW of peak power available for export (4 hours a day)

Operation of KGL into Zambian SystemOperation of KGL into Zambian System

506

0

200

400

600

800

1000

1200

1400

1600

1800

2000

2200

2400

2600

2800

3000

6/11 6/12 6/13 6/14 6/15 6/16 6/17

Day

Gen

erat

ion

(M

W)

-3,000

-2,500

-2,000

-1,500

-1,000

-500

-

500

1,000

Exp

ort

(M

W)

Kariba +Extension

KGU

ITT

OtherProposed

KGL

Other Existing

V/FALLS

Export

ExcessBaseload

DomesticPeakShortage2016 ScaledLoad

Installed CapacityInstalled Capacity

KGL can be used for regulating flow releases downstream of

KGU

A benefit-cost analysis was performed between four

alternative capacity configurations: 450, 600, 750 and 900

MW

The optimum development would be between 600 and 750

MW

Zambia Least Cost Capacity ExpansionZambia Least Cost Capacity Expansion

-

500

1,000

1,500

2,000

2,500

3,000

3,500

4,000

4,500

5,000

2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027 2028

MW

Year

Thermal Capacity KGL Capacity

Kariba Expansion Capacity ITT Capacity

Subtotal Mul. Kal. & Kab. Existing Zambian Hydro Generation

System Peak Adjusted Base Case System Required Capacity Adjusted Base Case

Peak and Required Capacity versus Zambian Hydro and Thermal Installed Capacity


� Hydropower Plants

� Zambezi River Basin: Mpata Gorge, Devil’s Gorge, Batoka Gorge

� Kafue River Basin: Kafue Gorge Lower (subject of this study)

� Luapula River Basin: Mumbotuta Gorge and MambilimaFalls

� Luangwa River Basin: Lusiwasi extension

� Thermal Power Plants


0

5

10

15

20

25

30

35

40

45

50

0% 20% 40% 60% 80% 100%

Capacity Factor

Usc

/kW

h

Coal-fired plant

Reciprocating Engine

Gas Turbine

Batoka

KGL 600-MW Base

KGL 600-MW Peak

KGL 750-MW Peak

Devil's Gorge

Luapula

Mpata

Screening Curves for Various Thermal and Hydro Options

OutlineOutline

� Zambia Electricity Demand

� Export Electricity Demand

� Zambia and Southern Africa Power Pool Transmission

� Installed Capacity

� Zambia Least Cost Expansion

� Hydrology

� Site selection

� Geology

� Project Description

� Construction Schedule and Costs

HydrologyHydrology

HydrologyHydrology

Climate

April – August (winter) Cool and dry

September – October (pre-rainy) Hot and dry

November – January (rainy) Hot and wet

February – March (post-rainy) Cool and wet

Flow data

The Kafue Gorge Upper daily flow data was used

Evaporation

Annual reservoir evaporation = 1,234 mm

HydrologyHydrology

Design flood

� Sufficient historic meteorological are not available.

� The flood peaks at the project site may lag by two to three

months from the occurrence of heavy rainfall.

� Physical nature of the basin does not allow reasonable

estimates of unit hydrographs to convert rainfall to runoff

hydrographs.

� A statistical approach was used to determine a flood of

10,000 year recurrence interval.

� A 10,000 year flood peak of 5,200 m3/s was used for the

KGL project.

Site SelectionSite Selection

GeologyGeology

� The KGL project is located in the physiographic region of

Zambia known as the Zambezi escarpment.

� Suitable foundation quality rock

� Limited site specific information for the underground

structures

� Strong and stable conditions are expected for underground

structures

� Orientation of underground arrangement

GeologyGeology

Construction materials are generally available within

reasonable distances from the site, with the exception of sand

for concrete.

• Materials for cofferdams;

• Concrete aggregates;

• Backfill material for retaining walls and other structural fills;

• Rock for riprap and slope protection; and

• Materials for access road construction

Project DescriptionProject Description


SegmentTunnel Lining

Approx. Length(m)

Inside Diameter

(m)

Velocity(m/s)

Headrace Tunnel

Concrete 180 4,8 5,4

Power Shaft

Concrete 150 4,8 5,4

Power Tunnel

Concrete 82 4,8 5,4

Power Tunnel

Steel 60 3,9 8,2

Tailrace Tunnel

Concrete 4,600 14,6 2,9

Waterway Data


Type of units Francis

Number of units 4 initial + 1 future

Rotational speed 300 rpm

Nominal power output, each unit 150 MW

Nominal discharge, each unit 97.4 m3/s

Gross head 182.7 m

Rated head 173.3 m

Rated power 156.4 MW

Main transformers 171 MVA, 50 Hz

Major Mechanical and Electrical Equipment

Construction Schedule and CostsConstruction Schedule and Costs

Before construction of the project begins, various important

tasks must be performed, including:

�Additional site-specific field and laboratory investigations

required for detailed design;

�Model-testing of the spillway;

�Site access and site preparatory work

60 months construction duration

Total Project Cost US$ 1,374 Million (2010 base date)

ConclusionConclusion

ConclusionConclusion

• Moreover, KGL has been consistently recommended as a

competent candidate project in the recent least cost expansion

plans carried out in SAPP level.

• Ongoing and proposed improvements of transmission lines joining

SAPP member countries should be able to facilitate wheeling of

the power in excess of Zambian consumption to the regional

export market.

Janus BassonBKS (PTY) LTD+27 12 421 [email protected]

Hydropower Africa 2010, August 18, 2010

Thank you for your attention

Bruno TrouilleMWH, USA+1 312 831 [email protected]

feasibility study of the kafue gorge lower hydroelectric ... · feasibility study of the kafue...

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