Improving system efficiency with fast flexible power - Case Thailand

Improving power system efficiency with Fast Flexible Power – Case ThailandSaara Kujala

Manager, Development & Financial Services

Wartsila Singapore Pte Ltd

1 © Wärtsilä 8 April 2023 Improving power system efficiency with Fast Flexible Power – Case Thailand / Saara Kujala

Flexibility in power systems• Power systems need right types of capacities to

meet requirements for base load, intermediate load and peak load

• From investment point of view, new base load plants are easy to justify due to the high committed operating hours

• Too much base load capacity pushes some base load plants to operate as intermediate load, increasing their cost of generation and reducing system flexibility

• Fast Flexible Power Plants (“FFP”) included as part of Thailand’s power system can improve the utilization of existing base load plants

• Considerable system level saving potential of 260 Million $ / year identified and quantified


Intermediate load

Base load

Peak load

00

6 12 18 24

20

40

60

80

100Demand %

Hour

Daily demand curve

Cost of electricity is variable!

Regulation

Installed capacity in Thailand - 2012• Almost 90% of the installed capacity is designed for

base load operation


*Plant Type Definitions• Base load capacity

• Slow start-up (>1hour)• Slow ramp-up speed and slow response to

changing grid conditions• Optimal efficiency at full load

• Flexible capacity• Fast start-up time (<10 minutes)• Fast ramp-up speed and fast response to grid

conditions• High efficiency at all loads for flexible load

following• Peaking capacity

• Fast start-up time • Fast ramp-up speed• Efficiency less important due to limited

operating hours

Plant GW Plant type*EGAT Power Plants 15 CCGT 6.9 Base load Fuel oil / Gas ST 2.2 Base load Fuel oil ST 0.3 Base load Coal ST 2.2 Base load Hydro 3.4 Flexible Diesel / Renewable 0.0 PeakingIPP 12.2 Bituminous coal 1.3 Base load CCGT 9.2 Base load Fuel oil/ Gas ST 1.6 Base loadSPP 2.2 CCGT 1.4 Base load Gas turbine (Simple cycle) 0.1 Peaking Coal 0.4 Base load Others 0.3 Base loadHydro imports 2.2 Base/ SeasonalTotal 31.5

Source: EGAT Annual report 2010EPPO Energy Statistics July 2012

15

20

25

30

35

40

45

50

0:30 4:30 8:30 12:3016:3020:30

GW

2012

2020

2030

14GW

10GW

7GW

How will Thailand address the daily load following requirement?

• Distinctive load profile with three daily peaks

• Annual peak demand growth rate of 3.9%

• 25GW of coal, nuclear, co-generation and renewable energy plants will enter into the system by 2030 providing base load electricity

• In addition, 25.4GW of new CCGTs in construction or planning – These plants will be used for load following

• Sufficient flexible power needs to be maintained in the system to cope with normal demand variations and with variations caused by increasing share of wind and solar generation


6GW

Daily load curve 2010

Daily load curve 2012-2030

Sources: EGAT (Daily load curve of May 12, May 22 and May 23, 2010); PDP 2010 Rev 3

Typical daily load curve by technology and fuel – May 2010

• Domestic hydro power plants are an important source of flexibility

• First technology to respond to load changes – primarily used for peak shaving

• Other generation capacity, most notably gas-fired power plants (CCGT, Gas boilers, SPP) also respond to load variations

• Varying operation profile negatively impacts the heat rate of CCGT plants

• System operation and regulation more challenging with slow responding gas-fired technology

• Value of fast and flexible power generation is evident and demonstrated in the daily load curve of domestic hydro power plants


Source: EGAT, May 12, 2010

GW System load curve (May 12, 2010)

0

5

10

15

20

25

0:3

0

2:3

0

4:3

0

6:3

0

8:3

0

10

:30

12

:30

14

:30

16

:30

18

:30

20

:30

22

:30

SPP IPP BituminousIPP CCGT IPP HydroLignite Gas CCGTGas ST HFOHydro

0

2 000

0

4 000

8 000

0

2000

4000

6000

Individual load curves (MW)

HFO ST

Lignite

NG CCGT

IPP Coal

SPP

IPP CCGT

IPP Hydro

Gas ST

EGAT Hydro

0

2 000

0

1 000

0

2000

0

3000

0

2 000

0

2 000

Load following with gas fired power generation

• A life-cycle cost analysis is conducted for single 700MW power plant that operates according to the same load curve as the power system in Thailand as a whole

• Efficiency and Levelized Electricity Cost (“LEC”) for a single plant are assumed to represent those for a larger system


0100200300400500600700

0:30 4:30 8:30 12:3016:3020:30

0100200300400500600700

0:30 4:30 8:30 12:3016:3020:30

Flexible Power System:550MW CCGT +

150MW Fast Flexible Plant

CCGT-Based System:700MW CCGT

Total generation cost ?

Total generation cost ?

0,0

5,0

10,0

15,0

20,0

25,0

0:30 3:00 5:30 8:00 10:30 13:00 15:30 18:00 20:30 23:00

May.12

Features of Fast Flexible Power with gas-fired combustion engines

• High open cycle efficiency (>45% for the plant)• Fast start and stop capability without EOH maintenance penalty• Multiunit configuration


Firm capacity

Firm capacity

22xW

18V

50S

GC

CG

T (2

-2-1

)

Life cycle cost evaluation for flexible power plants - Summary


0100200300400500600700

0:30 4:30 8:30 12:3016:3020:300

100200300400500600700

0:30 4:30 8:30 12:3016:3020:30

Plant Type: CCGT –Based system Flexible Power SystemPlant size: 700MW 550MW + 150MW = 700MW

CCGT efficiency 51.6% 53.2%

FFP efficiency - 45.3%

Total average efficiency (incl. fuel during generation and start-ups), net, LHV 51.6% 52.5%

Levelized Electricity Cost (incl. annualized capex, fuel, maintenance, start-up cost) 2.32 Bht/kWh

(77.2USD/MWh)2.22 Bht/kWh

(74.7USD/MWh)

CCGT - Optimized base load

FFP - Flexible generation

CCGT in load following

CCGT –Based System Flexible Power System

Saving potential for the Thailand Power System (2010)


CCGT-Based System Flexible Power System Total saving with Flexible Power System

Total gas fired capacity 2010 (GW) 18.3Annual generation 2010 (TWh) 106.7CCGT Installed capacity (GW) 18.3 14.4FFP Installed capacity (GW) - 3.9Calculated efficiency (%) 51.6% 52.5% 0.9%-pointCalculated fuel use (Million MMBtu / Year) 706 693 13

Generation cost (Million $ / Year) CCGT-Based System Flexible Power System

Total saving with Flexible Power System

Fuel charges (incl. start-up) 5 461 5 363 98

Fixed and variable O&M charges 647 615 32

Capacity charges 2 128 1 995 133Total cost of electricity 8 326 7 973 263

Improved efficiency and lower fuel consumption in Flexible Power System (Scenario II)

FFP impacts the existing plants

263 Million USD saving in annual costs with Flexible Power System (Scenario II)

Conclusions


• Planning process for new power plants should be driven by intended plant use (base load, flexible load, peaking).

• Planning process for new power capacity should recognize the impacts on the load profiles and utilization of existing plants.

• Fast Flexible Power plants can help to improve the performance of the power system.

• Fast Flexible Power can be implemented gradually as part of the Power Development Plan to match investment timing with power demand growth.

Business

Improving system efficiency with fast flexible power - Case Thailand