Prestedge Retief Prestedge Retief Dresner WijnbergDresner Wijnberg

NGQURA POWER PROJECTNGQURA POWER PROJECT

COOLING WATER SYSTEMSCOOLING WATER SYSTEMS

Intake and Outfall ConsiderationsIntake and Outfall Considerations

Prestedge Retief Prestedge Retief Dresner WijnbergDresner Wijnberg

INTAKE & DISCHARGE CONCEPTSINTAKE & DISCHARGE CONCEPTS

Typical intake pumphouse Typical intake pumphouse footprintfootprint

Typical surface outfallTypical surface outfall

Prestedge Retief Prestedge Retief Dresner WijnbergDresner Wijnberg

TYPICAL INTAKE PUMPHOUSE CONCEPTTYPICAL INTAKE PUMPHOUSE CONCEPT

4.0 m20 m

INTAKE PUMPHOUSE - PLAN VIEW

10 m

4 DUTY PUMPS (PLUS 1 STANDBY)7 m3 /s EACH

Typical Cross-sectionTypical Cross-section

Typical Plan ViewTypical Plan View

Prestedge Retief Prestedge Retief Dresner WijnbergDresner Wijnberg

Prestedge Retief Prestedge Retief Dresner WijnbergDresner Wijnberg

TYPICAL MULTI-PORT DIFFUSER DISCHARGE CONCEPTTYPICAL MULTI-PORT DIFFUSER DISCHARGE CONCEPT

Multi-port Diffuser with 15 x 0.6m diam Discharge Ports

3 x 2.0m diam Outfall Pipes(Plus 1 Standby)

Prestedge Retief Prestedge Retief Dresner WijnbergDresner Wijnberg

CCGT CONCEPT, COOLING SYSTEM ALTERNATIVES & WATER QUALITY GUIDELINES

STEAM CYCLE COOLING TECHNOLOGY

DIRECT SEA WATER COOLING SYSTEM

EVAPORATIVE CLOSED COOLING SYSTEM

100,000 m3

10oC – 12oC

Sodium Hypochloride (NaOCl)

0.1 mg/l (max) -

4,000m3 (make up water) 2,600m3 (purge discharge)10oC Above make up water.5oC Above ambient air temp.Sodium Hypochloride (NaOCl)0.1 mg/l (max)

1.5 Times original seawater (i.e. 1.5 x 35,000 mg/l = 52,500 mg/l).

FLOW RATE:

TEMP RISE:

ANTI-FOULING AGENT:

CHLORINE RESIDUAL:

BRINE CONC. FACTOR:

vs

Prestedge Retief Prestedge Retief Dresner WijnbergDresner Wijnberg

Water Quality GuidelinesWater Quality Guidelines

SA WATER QUALITY GUIDELINESSA WATER QUALITY GUIDELINES WORLD BANK GUIDELINES FOR NEW WORLD BANK GUIDELINES FOR NEW THERMAL POWER PLANTSTHERMAL POWER PLANTS

INTERNATIONAL TARGET VALUES INTERNATIONAL TARGET VALUES FOR NATURAL MARINE FOR NATURAL MARINE

ENVIRONMENTENVIRONMENT

ZONE OF IMPACTZONE OF IMPACT KEPT TO A MINIMUM; DETERMINED KEPT TO A MINIMUM; DETERMINED THROUGH EIATHROUGH EIA

100m FROM POINT OF DISCHARGE 100m FROM POINT OF DISCHARGE (ASSUMING NO SENSITIVE ECO-(ASSUMING NO SENSITIVE ECO-

SYSTEMS PRESENT)SYSTEMS PRESENT)

--

TEMPERATURE INCREASE AT EDGE TEMPERATURE INCREASE AT EDGE OF ZONEOF ZONE

+/- 1 DEGREE C+/- 1 DEGREE C LESS THAN OR EQUAL TO 3 LESS THAN OR EQUAL TO 3 DEGREES CDEGREES C

LESS THAN 2 DEGREES CLESS THAN 2 DEGREES C

(AUSTRALIA)(AUSTRALIA)

RESIDUAL CHLORINE LEVEL AT RESIDUAL CHLORINE LEVEL AT EDGE OF ZONEEDGE OF ZONE

0.2mg/l AT DISCHARGE I.e. PRIOR TO 0.2mg/l AT DISCHARGE I.e. PRIOR TO DILUTIONDILUTION

7.5 7.5 g/l (4d ave); 13 g/l (4d ave); 13 g/l (1h ave); NOT g/l (1h ave); NOT TO BE EXCEEDED MORE THAN ONCE TO BE EXCEEDED MORE THAN ONCE

EVERY 3 YREVERY 3 YR

SALINITYSALINITY CHANGE < 5% FROM BACKGROUNDCHANGE < 5% FROM BACKGROUND

Prestedge Retief Prestedge Retief Dresner WijnbergDresner Wijnberg

INTAKE & DISCHARGE CONSIDERATIONSINTAKE & DISCHARGE CONSIDERATIONS

Prestedge Retief Prestedge Retief Dresner WijnbergDresner Wijnberg

Prestedge Retief Prestedge Retief Dresner WijnbergDresner Wijnberg

A M J

2Q06

J A S

3Q06

O N D

4Q06

J F M

1Q07

AA M J

2Q07

J A S

3Q07

O N D

4Q07

J F M

1Q08

M J

2Q08

J A S

3Q08

O N D

4Q08

J F M

1Q09

Sea Water Cooling* & EIA LinkagesSea Water Cooling* & EIA Linkages

ToR

Data Collection

Concept & Prelim Design

Detail Design

RfP

Select

Mobilise & Construct – 24 months

2009/10 O N D J F M

Scoping

SpecialistToR

EIR EMP

ROD

Appeal

Bid Documentation

EIA designand

schedule

risk

Bra

insto

rm s

olu

tion

s

Pre

ferr

ed

Op

tion