Giancarlo Benelli Stefano Malloggi Sauro Pasini Nicola Rossi

Enel - Engineering & Research Division

FOSSIL FUEL POWER PLANTS: SOLUTIONS TO IMPROVE FLEXIBILITY

Evolution of power generation markets in EU, Italy, Spain

Enel plants in the current production scenario

Enel’s actions to increase competitiveness of CCGT plants

Power generation on islands

Remarks

Outline

2

Source: Market Observatory for Energy, June 2012

Note: Hydro is considered within RES

EU-27 electricity generation (1990-2000-2010)

(Gross electricity generation by fuel)

EU power generation structure evolution

3

Source: GSE 2011 report

Including hydro

Disappearance of oil

generation

Strong increase in

RENEWABLES

Slight decrease in gas

Italian power generation sector Evolution of the generation mix

4

2007-2011: installed gas capacity has increased, but in the last years an important reduction in generation has occurred and this trend is not changing

Italian market Installed gas capacity vs. production

279

300

319

314

98

117

173

145

13,2

18,1

42,747,8

0

10

20

30

40

50

60

70

0

50

100

150

200

250

300

350

1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012

Inst

all

ed

ca

pa

city

[G

We

]

Pro

du

ctio

n f

rom

ga

s -

Co

nsu

mp

tio

ns

[TW

h]

Consumptions [TWh] Production from gas [TWh] Installed capacity, GT+GTCC [GWe]

Italy

5

Source: Market Observatory for Energy, June 2012

Strong reduction of coal

generation

Reduction of nuclear

generation

Strong increase in gas

and renewable generation

Spanish power generation sector Evolution of the generation mix

6

Source: REE annual reports

Sep the 17th : Wind covers 1% of the demand Sep the 24th : Wind covers 64% of the demand

Strong increase of wind installations in the last decade leaded to CCGT production reduction

CCGT fleet used to compensate wind production variations

Source: “Situation of CC Electric Power Generation in Europe.” EPRI Program 79. Nashville October 2nd 2012

Annual production: wind vs CCGT

Spanish market Backing up renewable production

7

Energy offered by GSE on energy market 2006-2013:Hourly cost comparison

8

Increase of power ratios: RENEWABLES/fossil based;

Priority dispatching of renewables “imposed by law” and increase of cycling duty;

Requirement of back-up capacity and Conventional Power Plants are required to take on “auxiliary services”;

Increasing environmental constraints;

Volatility of grid capacity;

Increase of electric consumption trends;

Hourly based tariffs for electricity sale;

Social acceptance difficulties for new power sites as well as new power grids.

Power generation New paradigms: low carbon ,flexibility, efficiency

9

Type of Plants Operation parameters

Nuclear Thermal power

Gas Turbine Combined Cycle

Heavy Duty Gas Turbine

Areod. Gas Turbine

Electrochemical batteries utility scale

Smart Power Gen.

Hydro power

Pump Hydro

Start up to synchronization

(minutes)

>1400 >50 6-13 6 6 Instantaneous

0,5 <1 <1

Start to full load (minutes)

>2000 >180 50-90 13-30 8 - 3-5 <2 <2

Stop from full load

(minutes)

30-60 10 5 1 <1 - <1 - -

Ramp – up rate (%/minutes)

3 3 2 3-5 3 - 5 - >20 >50 >50

Modern power plants Starting and stopping time

Sources:

•Golinelli: Smart power cogeneration-Quarta conferenza nazionale sull’efficienza energetica-Rome-November 21-2012

• Jacob klimstra -Markus Hotakainen – Smart power generation 10

Main problems • Difficulties in compensating the fast variations using conventional steam

based power plants

• CO2 /Kwh and (CAPEX + OPEX) per kWh increasing due to lower utilization factors of power plants.

The efforts to balance renewable energy fluctuations

Enel efforts are focused to create better conditions to deliver competitive

and clean energy by improving operation flexibility and modifying the technology mix of power generation park:

• obtaining a wider operation field by reducing minimum loads; • optimizing power plant performances at lower loads; • introducing operation procedures for faster starts and stopping

without impacting on reliability and environment ; • optimizing fuel flexibility (coal ,natural gas and bio-fuels).

Thermoelectric Power Plants Enel efforts to optimization and flexibility

11

Strong contraction of CCGT production in the last five years, especially in 2012

because of the installation of about 10GW of PV power

Increase of the annual startups per unit of produced power

0

5.000

10.000

15.000

20.000

25.000

2007 2008 2009 2010 2011 2012

Pro

du

ctio

n [

GW

h /

ye

ar]

Annual production

Italy: CCGT power generation The new role of GTCCs: the Enel case

0

20

40

60

80

100

120

2007 2008 2009 2010 2011 2012

Sta

rts [

No

/ 1

00

0 G

Wh

]

No of starts / production

12

0

50

100

150

200

250

300

350

400

01

/06

/20

05

02

/06

/20

05

03

/06

/20

05

04

/06

/20

05

05

/06

/20

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06

/06

/20

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/06

/20

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08

/06

/20

05

09

/06

/20

05

10

/06

/20

05

GR

OS

S P

OW

ER

[M

W]

0

50

100

150

200

250

300

350

400

05

/05

/20

12

06

/05

/20

12

07

/05

/20

12

08

/05

/20

12

09

/05

/20

12

10

/05

/20

12

11

/05

/20

12

12

/05

/20

12

13

/05

/20

12

14

/05

/20

12

GR

OS

S P

OW

ER

[M

W]

2005 2012

Typical weekly trend of combined cycle power

Increased number of startup / shut down cycles

Reduced operation at base load

Operation at minimum environmental load during nights

Minimum load

Base load

Italy: CCGT power generation The new role of GTCCs: the Enel’s case

13

Enel’s Gas Turbine Diagnostic System

15 GT and 12 coal power plants

monitored

Supporting the operation through

statistics rules for anomaly

prediction and analysis

Lifetime monitoring & management

Today Target

Life & maintenance models: tracking

history of each GT component

On-line lifetime calculation

Choosing start-up curve for optimizing

lifetime and/or market request

Source: GE FlexEfficiency 50

Enel’s actions to increase competitiveness of CCGTs Advanced diagnostic tools for lifetime monitoring & management

14

Power generation on Island

Main peculiarities

Even bigger islands are often not connected to the mainland, hence

self-reliability is a must

Power generation has costs that can reach 3 times mainland plants

Even small quantity of renewable generation can lead to grid

instability (lower grid inertia due to small size)

Very high seasonal load variation possible (summer tourism)

Strong constraints for new buildings/plants

High incentives for renewable in some countries

15

Grid stability support

Optimize conventional generation operation for fuel

saving and emission abatement

Life extension of conventional assets

Optimization of reserve assets

Support renewable integration

Conventional generation optimization

Storage systems on islands

Main drivers

Increase of renewable hosting capacity

Optimization of electric supply

Decrease of average cost of electricity

Increase of grid self-reliability

Frequency regulation

Voltage support

Outages prevention and response

Diesel con accumulo

CaricoDiesel senza accumulo

FV

Accumulo

Diesel operation with

storage

Diesel operatin

without storage

PV production

Storage duty cycle

Time [15 mins]

Po

we

r[k

W]

Load

16

Remarks

Large scale integration on grid of renewable and their stochastic

availability forces other power plants to frequent loadings and unloading to balance energy system.

Compensating for the fast variations lowers the utilization factor of the

steam power plants and the utility companies are forced to study specific innovation to be introduced in order to increase flexibility as well as to improve efficiency at reduced load; lower utilization factors of power plants increases the specific capital costs per kWh but also maintenance costs per kWh.

Energy storage technologies are still expensive even though would be

useful their integration on the grid for conjugating flexibility, efficiency, environment and prompt fluctuation of renewable.

17

Thank you for your attention