Fausto Batini
Enel – International
Rome – Italy fausto.batini@enel.it
Rome, 2006 5th July
Geothermal energy

Contents
1
° PART
1.
introduction
2.
Geothermal energy basic concepts
•
Heat sources
• Geothermal systems
3.
The geothermal industry worldwide
• Electric energy generation
•
Direct use application
2 ° PART
1.
Resource assessment and project development
• Ranking of geothermal prospects
•
Project development
• Operation and maintanamce
2.
Drivers & barriers for the geothermal energy growth
•
Technological challenges
• Economic and environmental sustainability
3.
Conclusions
Geothermal energy

Contents
1
° PART
1.
introduction
2.
Geothermal energy basic concepts
•
Heat sources
• Geothermal systems
3.
The geothermal industry worldwide
• Electric energy generation
•
Direct use application
2 ° PART
1.
Resource assessment and project development
• Ranking of geothermal prospects
•
Project development
• Operation and maintanamce
2.
Drivers & barriers for the geothermal energy growth
•
Technological challenges
• Economic and environmental sustainability
3.
Conclusions
Geothermal energy

Geothermal energy
Enel market capitalization
•
The principal electricity operator in Italy with the leading position in the generation, transmission*, distribution and sale of electricity
•
Strong presence in the gas market
• One of the world largest operators in the energy sector
E.ON AG
ENEL SPA
RWE AG
TOKYO ELECTRIC POWER CO INC
EXELON CORP
NATIONAL GRID TRANSCO PLC
SUEZ SA
DUKE ENERGY CORP
DOMINION RESOURCES INC/ VA
ELECTRABEL SA
IBERDROLA SA
SOUTHERN CO
ENDESA S.A.
TXU CORP
KANSAI ELECTRIC POWER CO INC
CHUBU ELECTRIC POWER CO INC
CENTRICA PLC
SCOTTISH POWER PLC
FIRSTENERGY CORP
HUANENG POWER INTR INC- A
5.000
10.000
15.000
20.000
25.000
30.000
35.000
40.000
45.000
50.000
mkt cap (Eur mn)
Source: Bloomberg
* Enel owns 36,14% of the share capital of Terna and has already signed an agreement for the sale of up to 30% of the company

Geothermal energy
America
SPAIN
Europe
America
• 1.592 MW Thermal
• 671 MW Hydroelectric
• 600,000 customers
!
50% of EUFER:
• 294 MW Wind
• 89 MW Hydroelectric
• 62 MW Cogeneration
RUSSIA
North Western thermal power plant
• 286 MW Hydroelectric
SLOVACCHIA
•66% of Slovenske Elektrarne
ROMANIA
•51% of Dobrogea
ITALIA
• 30 million customers (power)
• 2 million customers (gas)
• 42.000 MW
•51% of Banat
•1.4 million customers
BULGARIA
• 67% of Maritza East III:
• 732 MW Thermal
• 293 MW Hydroelectric
• 20 MW Wind
• 115 MW Geo (12,7% of LaGeo)
53.161 MW, 750 power plants, 1.000.000 km grid, over 34 million customers

Contents
1
° PART
1.
introduction
2.
Geothermal energy basic concepts
•
Heat sources
• Geothermal systems
3.
The geothermal industry worldwide
• Electric energy generation
•
Direct use application
2 ° PART
1.
Resource assessment and project development
• Ranking of geothermal prospects
•
Project development
• Operation and maintanamce
2.
Drivers & barriers for the geothermal energy growth
•
Technological challenges
• Economic and environmental sustainability
3.
Conclusions
Geothermal energy

Geothermal energy
Geothermal heat source
Geothermal energy is, literally, the heat contained within the Earth that generates geological phenomena on a planetary scale.
Temperature gradient in the earth is 33 °C/km (In the geothermal areas > 100 °C/km)
A mean heat flux at the earth's surface is around 16 kW t
/ km 2 (In the geothermal areas > 100 kW t
/ km2 )
42.000.000 MW t dissipated to the atmosphere and space
Only a fraction of this energy can be recovered and exploited by man.

The thermal engine in the Earth
Geothermal energy
Immense volumes of deep hotter rocks, less dense and lighter than the surrounding material, rise with convective movements towards the surface

Geothermal energy
Geothermal areas worldwide
The heat flux tends to be strongest along tectonic plate boundaries where volcanic activity transports high temperature material to near the surface.
However, even in parts of the world far from plate boundaries, there can still exist areas of higher than average natural heat flow.

Geothermal system
Utilization of geothermal energy has been limited to areas in which geological conditions permit a carrier (water in the liquid phase or steam) to 'transfer' the heat from deep hot zones to or near the surface, thus giving rise to geothermal system
Power plant
Steam gathering system
Production wells
Meteoric water
Drilling rig
Reinjection well
Caprock
Thickness 500 – 1500 m
Impervious rocks
Reservoir
Porous
– fractured rocks
Tickness 500 – 1500 m
T = 150 – 300 °C
Hot fluid
Heat source
Depth 5-10 km
T > 600- 700 ° C
Geothermal energy

Geothermal system
Geothermal energy

Geothermal systems
Geothermal energy

Electric energy generation
Geothermal energy
This is the most common type of geothermal power unit.
NAMEPLATE CAPACITY :
5 - 60 MW
NAMEPLATE CAPACITY :
2 - 10 MW

Direct use of geothermal heat
Geothermal energy

HDR Project at Soultz: the Pilot Plant concept
Geothermal energy
Develop advanced technology to use the huge thermal energy amount contained in the earth crust

Contents
1
° PART
1.
introduction
2.
Geothermal energy basic concepts
•
Heat sources
• Geothermal systems
3.
The geothermal industry worldwide
• Electric energy generation
•
Direct use application
2 ° PART
1.
Resource assessment and project development
• Ranking of geothermal prospects
•
Project development
• Operation and maintanamce
2.
Drivers & barriers for the geothermal energy growth
•
Technological challenges
• Economic and environmental sustainability
3.
Conclusions
Geothermal energy

Once upon a time at the underworld watchdog site... Larderello (Italy)…
Geothermal energy
… in 1817 a small group of entrepreneurs formed the first geothermal firm starting the extraction of boric acid by evaporation of the waters of the many geothermal lagoons present in the Larderello region.

Geothermal energy
…
… in 1827 the first approach to explore the hell …
… and to measure the power of the steam

…
In 1904 the first experiment of electric energy generation
Geothermal energy
The first commercial electric power plant
Larderello 1 ( 1916 )
3x3000kW (indirect cycle)

Geothermal energy
Geothermal highlights in Italy
Larderello
• since 1913
• exploited area 250 km 2
• steam dominated reservoir
• efficient capacity:463MW
Florence
Roma
Amiata
• since 1954
• exploited area 50 km 2
• Water dominated system
• efficiente capacity :88 MW
Radicondoli - Travale
•Since 1950
•Exploited area 30 km 2
•steam dominated reservoir
• efficient capacity:160 MW
Same geothermal system at depth over 3000 extending about 400 km 2
Year 2005
Efficient capacity (MW) 711
Net generation (GWh) 5.036
Heat distributed (Tcal ) 235
CO2 avoided (Mt) 3,4
TEP saved (MTEP) 1,13

Geothermal energy
Geothermal exploration & production process
RESOURCE
EXPLORATION
& ASSESSMENT
DRILLING
ENGINEERING
& CONSTRUCTION
OPERATION &
MAINTANANCE

An interdisciplinary integrated approach is applied to build an accurate subsurface geological model of the geothermal system
…
Geothermal energy
Geological & structural model
… to select the most promising prospect and to predict the drilling targets

Geothermal energy
Vertical and directional wells are drilled from the same pad at depth of 1000
– 4500 m
Montieri 1 well
Steam production over 240 tonnes/h of steam

Design & construction of the power system
Geothermal energy
Steam pipeline
(lenght range :1-10 km)
Power plants
20 MW each one

Geothermal energy
Architectural solutions to minimize the visual impact
Reduction of gas emission AMIS
(process for H2S and Hg removal)
Abatement
 Hg
 H
2
S
>90%
70-80%

Geothermal energy
Cooling towers
Production well
Steam gathering system
Electric power plant
Steam flow
Water
Reinjection well
Integrated management of geothermal resources for production optimization

Enel’s geothermal assets in Italy
711 MW operating capacity
• 31 Units in operation
• Range 6.5 MW - 60 MW
• 508 wells
• 408 km steam&water pipelines
Geothermal energy

Geothermal energy
Geo-heat supply in Italy
DISTRICT HEATING & GREEN HOUSES

Geothermal energy
3000
2500
2564
2000
1500
1930
The total installed capacity is 8,933 MW
8,000 MW running and supplying 56,786 GWh an increase of 12% and 15% respectively with respect to year 2000
Enel
1000
500
0
953
838
711
535
435
202
163
151 121
79 77
33 28 20 16 20
Fonte: IGA 2005

Geothermal energy
Geothermal installed capacity
About 8,000 MW in operation and supplying 56,786 GWh
25%
Double Flash
8%
Binary
1% Back Pressure
Dry Steam
Single Flash
29%
37%
• 2/3 of the total installed capacity are for dry steam and single flash units
•
Binary units are increasing, but with a lower value of capacity per unit.
Fonte: IGA 2005

Geothermal energy
GEOTHERMAL ENERGY FOR
ELECTRICITY GENERATION
56875 GWh in 2004
12%
5% 2%
37%
Energy saving & pollution avoided
44%
AFRICA
AMERICAS
ASIA
EUROPE
OCEANIA
Electric use
• Energy saving (*) of fuel oil per year
96,6 million barrels or 14, 5 millions tonnes
• Carbon pollution avoided (millions tonnes year)
3 (natural gas) or 13 (oil) or 15 (coal)
Direct uses
• Energy saving (*) of fuel oil per year
123,4 million barrels or 18,5 millions tonnes
• Carbon pollution avoided (millions tonnes year) 4 (natural gas) or 16 (oil) or 18 (coal)
44%
GEOTHERMAL ENERGY FOR
DIRECT USE OF HEAT
72632 GWh
21%
32%
AFRICA
AMERICAS
ASIA
EUROPE
OCEANIA
Total energy saving of fuel oil per year over 220 million barrels
Total carbon pollution avoided per year over 39 (oil) million tonnes
(*) generating electricity with 0,35 efficiency factor

World geothermal potential
Geothermal energy
… up to 72.500 MW exploitable with existing technologies while future technologies will allow the exploitation of up to 140.000 MW …
Source: World Bank

Geothermal energy
• Canada
• Usa (1935 MW)
Geothermal energy worldwide development
Turchia (18 MW)
Iceland (202 MW)
•France -
Guadalupe (15 MW)
• Portugal (13 MW)
• Italy (711 MW)
Iran
Cina (19 MW)
Russia (79 MW)
Japan (530MW)
• Indonesia (838 MW)
• Filippine (1838 MW) • Mexico (953 MW)
• Nicaragua (38 MW)
• El Salvador (119 MW)
• Costa Rica (163 MW)
• Guatemala (29 MW)
• Cile
• Bolivia
• Perù
• Argentina
• Kenia (129 MW)
• Ethiopia (7,3 MW)
• New Zealand (403
MW)
Areas with high potential
( MW in operation)
Source : Bertani
WGC 2005
8900 MW in operation forecasted to year 2010

Geothermal energy
Val di Cornia profondo
Selva - Bruciano
Sesta -
Montecastelli
Chiusdino
Exploration program
2004-2008

3D seismic

11 wells at depth of 3500-4500

68 € millions investment
Lagoni Rossi profondo
Montieri
100 MW additional in the next 5 years

Geothermal energy
Nicaragua
Hoyo Mt.Galan
Chiltepe
Enel’s worldwide development
North America
Far East projects
Market opportunity under evaluation under evaluation
Cile
Apacheta
El Tatio –
La torta
Partenership with LaGeo
GEONICA s.a.
2 project under exploration
Calabozo
Chillan
Ahuachapan
Berlin
El Salvador
Partenership with LaGeo
119 MW in operation
55 MW under construction
Partenership with ENAP
ENG s.a & GDN s.a.
4 project under exploration

Contents
1
° PART
1.
introduction
2.
Geothermal energy basic concepts
•
Heat sources
• Geothermal systems
3.
The geothermal industry worldwide
• Electric energy generation
•
Direct use application
2 ° PART
1.
Resource assessment and project development
• Ranking of geothermal prospects
•
Project development
• Operation and maintanamce
2.
Drivers & barriers for the geothermal energy growth
•
Technological challenges
• Economic and environmental sustainability
3.
Conclusions
Geothermal energy

Thanks for your attention
For any further information please contact me at the following e-mail address: fausto.batini@enel.it
Geothermal energy