Change happens –

Stay in controlArnaud Gouet

General Manager , Power Plants Southern Africa

November 2010

IRP 2010 Draft 2, Public Hearings

November 2010

Why is flexibility so important for the system?

• Intermediate load

– Normal daily load variations due

to consumer needs

– Increase of wind and solar

power introduce uncertainty

which leads to sudden, large

load variations

• Good intermediate plant

– Fast start & stop, and restart

– High efficiency: part load and

high load

– Good performance in hot and

cold conditions – demand peaks

take place at extreme

temperatures

– Competitive in BASELOAD

September 20102 © Wärtsilä

Intermediate load

Base load

0

0

6 12 18 24

20

40

60

80

100

Demand %

Hour

DAILY DEMAND VARIATION

Regulation

Dedicated

Plants

Dedicated

Plants

IRP 2010 South Africa

Wartsila in the USA

IRP 2010 South AfricaNovember 2010

1000 MW of gas fired Wärtsilä power

plants in the USA

• Plant size range 50…200 MW

• Location in regional load centers

• Operation mode: Multitasking!

First to start when wind calms down

Base load on high tariff hours

Peaking in the morning and evening

Plains End, Colorado, USA

• Natural Gas, 113 MW, Intermediate/Peaking Plant based on spark ignition gensettechnology

• Located in Denver, Colorado area at 1875 Masl with performance guarantees based on ambient air temperature of 37 deg cel and the site elevation : 44 % efficeincy

• Has 20 X 18V34SG Gensets

• Commercial since May, 2002

• Provides superior ancillary services and other benefits

• No water Usage

IRP 2010 South AfricaNovember 2010

18x 18V50DF, 300 MW Dual Fuel Power Plant Sangachal, Azeirbadjan

November 2010 IRP 2010 South Africa

Electrical

efficiency

Flexibility

Starting time

Ramp rate

Part load oper.

Operational flexibility vs. Energy efficiency

September 2010 UTILITY SUMMIT IZMIR 28-29.9.20106 © Wärtsilä

40%

50%

Medium High

Wärtsilä

SC

Aero-

GT’s

Industrial

GT’s

Coal

CCGT’s

Steam Power Plants Simple Cycle Recip. Engines

Nuclear

Wärtsilä

CC

30%

Low

49,9%

7214 kJ/kWh

48,6%

7407 kJ/kWh

pf = 0.8

46,2 %7781 kJ/kWh

pf = 0.8

46,1 %7815 kJ/kWh

Pf = 0.95

45,8 %7854m kJ/kWh

pf = 1.0

50,2 %7171 kJ/kWh

Pf = 0.95

Generator

terminals

0% tolerance

Plant busbar

MV-Side

0% tolerance

- Aux cons.

Plant interconnect

HV-Side

0% tolerance

- Step up loss

Generator

terminals

5% tolerance

Engine

shaft

5% tolerance

SCGE

0-40°C Air

<200 masl

MN >90

CCGE 315MW

25°C Air

<200 masl

MN>90

RH 30%

Typical values for 16x18V50SG with one pressure combined cycle plant solution with 15 bar/340°C steam

Engines with low noise radiator cooling (dry). CC with cooling tower.

Guarantee values are dependant on actual plant location, configuration and selected plant equipment

16x18V50SG SC and CC plant efficiency

November 2010

G

Simple CycleDry (Radiator cooled)

Combi CycleDry (Engines)

Cooling tower (CC)

7 © Wärtsilä

50.0 %7200 kJ/kWh

pf = 1.0

IRP 2010 South Africa

Start up and loading of a Gas Engine power plant compared to a GTCC

November 2010

0%

20%

40%

60%

80%

100%

120%

0 20 40 60 80 100 120 140 160 180

Minutes

Lo

ad

[%

]

GE power GT power

Gas Turbine Combined Cycle

Gas Engine

IRP 2010 South Africa

Only 10 minutes from start command to full load

Partial Load Performance

Comparing the Efficiency of Simple Cycle and Combined Cycles for

Reciprocating Engines and CCGT

1st Engine2nd Engine Steam Turbine

1st Gas Turbine2nd Gas Turbine

Steam Turbine

The multi unit engine

power plant has very

high part load efficiency.

November 2010 IRP 2010 South Africa

Reliability & Availability of Reciprocating Engines

Wärtsilä single gas engine availability over 20 years life Wärtsilä Power Plant anticipated power production capability

As the Wärtsilä power plant consists of 3 power plants with each 16 Gas/HFO engines, it is

unlikely that its available output will go below 1000 MW.

The red dashed line show the levelized 20-year average

availability of 93 %.

The available output of the Wärtsilä power plant is above

1030 MW during 7,500 h/a. Based on the above the overall

plant availability will be appr. 95 %

84 %

86 %

88 %

90 %

92 %

94 %

96 %

98 %

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20

Year

Avai

ab

ilit

y

0

50

100

150

200

250

300

850

950

1050

0 2000 4000 6000 8000

Hours/year

48 Engines running 47 Engines running

November 2010 IRP 2010 South Africa

Why Should Engines be added as an alternative to GTs

November 2010 IRP 2010 South Africa

0

5

10

15

20

OCGT Gas Engine CCGT Gas Engine CC

Water usage, l/MWh

0

100

200

300

400

500

600

700

OCGT Gas Engine CCGT Gas Engine CC

CO2 emissions (kg/MWh)

0

2000

4000

6000

8000

10000

12000

OCGT Gas Engine CCGT Gas Engine CC

Heat Rate, kJ/kWh, avg

0,3

0 za

r/k

wh

0

1000

2000

3000

4000

5000

6000

OCGT Gas Engine CCGT Gas Engine CC

Overnight capital costs (R/kW)

0,5

0 za

r/k

wh

Diesel Peaker Plant Comparison

November 2010 IRP 2010 South Africa

Yearly saving

3 hours per day ( 260 days)

ZAR 721 810 000 / year*

ZAR/ Mwh

*Diesel at zar 6/l.

0.0

50.0

100.0

150.0

200.0

250.0

300.0

350.0

400.0

Reciprocation Engines Gas Turbine

Capital

Fixed O&M

Variable O&M

Consumables ( urea for Denox)

Fuel

Conclusion : Do not limit IRP to GTs , include ENGINES

November 2010 IRP 2010 South Africa

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