The El-Borma ISCCS Case Study - German Aerospace Center

Towards a Sustainable Implementation of Solar Thermal Power Plants Technology in the MENA

www.dlr.de/enerMENA

The El-Borma ISCCS Case StudyMatthias Günther, Jürgen Dersch, Thomas Fend, (DLR)

The Joint German-Jordanian Workshop 2012Amman February 27th – 29th

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Outline

1. The El Borma Oil-Field and its Current Power Supply

3. Methodology

2. The Future Concept

4. Results

5. Conclusions

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The El Borma Oilfield

‐ utilization since 1966 (peak extraction 1985: 70 Tb/d, today: 10 Tb/d)

‐ 2010 concession extended to 2043

‐ binational oilfield in Tunisia and Algeria

‐ biggest one in Tunisia

‐ electricity supply with own power station

‐ secondary extraction

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The El Borma Oilfield

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Stakeholders

STEG (Société Tunisienne d’Electricité et du Gaz)

national utility

STEG ER (STEG Energies Renouvelables)

SITEP (Société Italo‐Tunisienne d’Exploitation Pétrolière)

Founded in May 2010, co‐ordinates the Tunisian Solar 

Plan

operating company, belongs to ENI and the state of 

Tunisia

ENI 

Italian Oil and Gas enterprise

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The Existing Power Supply

‐ commissioning: 1979/1980 (Fiat)

‐ 3 gas turbines à 13,5 MW(2 in operation, 1 in stand‐by)

‐ efficiency: 20‐21%

11 kV‐Grid with 114 km total length

oil pumps55%

water injectionpumps28%

STEG (gas‐conditioning and ‐transport)   8%

misc. (lightning, AC, kitchens etc.)    8,5%

other companies0,5%

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Consumers (2009)

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Load Distribution (2009)

‐ low seasonal differences

‐ low daily variation

0

5000

10000

15000

20000

1 2 3 4 5 6 7 8 9 10 11 12Monat

Gasverbrauch [1000 Nm3]

elektrische Energie [MWh]

mittlere Leistung [kW]

gaselectricityaverage power

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1. The El Borma Oil-Field and its Current Power Supply

3. Methodology

2. The Future Concept

4. Results

5. Conclusions

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Future Plans for the El Borma Electricity Supply

good DNI conditions 

32 year old plant 

possible costs for future gas consumption 

low efficiency

interest for modernization of the plant

economic powerful actors

El Borma plant joins Tunisian Solar Plan as a CSP‐reference project 

Overall objective of the Tunisian Government to force the development of RE and to ncrease the efficiency (Tunisian Solar Plan)

good site for CSP‐project

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The ISCCS El Borma as part of the Tunisian Solar Plan

40 Projects in 5 groups:

1. Solar Energy  (17)

2. Wind Energy (3)

3. Energy efficiency      (7)

4. others (7)

5. Studies and realization

of the TSP (6)

TSP: 

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Future Power Requirements 

present maximum load of the El Borma Oil field

additional demand STEG (expansion of the gas‐pipeline capacities)

ENI‘s additional demand for a second oil‐field

22 MW

+   8 MW

+  13 MW

43 MW

1. The El Borma Oil-Field and its Current Power Supply

3. Methodology

2. The Future Concept

4. Results

5. Conclusions

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Parabolic Trough or Solar Tower?

‐ total power: 43 MW 

‐maximum solar contribution: 5 MWel

Calculation of the fuel savings by the generation of solar heat and 

solar generated electricity

Preconditions:‐ ISCCS with solar input into steam cycle

comparison of tower or trough solution

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ISCCS‐Configurationsolare backing of the evaporator parallel solar generation of live steam

solar superheating needs high temperatures

point focussing systems, direct steam generating parabolic trough or trough with salt as a HTM

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ISCCS‐Configuration

El Borma: solar evaporation and 

superheating

parallel solar generation of live steam

solar superheating needs high temperatures

point focussing systems, direct steam generating parabolic trough or trough with salt as a HTM

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‐ solar tower with open 

volumetric air  receiver 

‐ direct steam trough

steam parameter:

‐ 440°C

‐ 45 bar

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ISCCS‐Configurationparallel solar generation of live steam

solar superheating needs high temperatures

point focussing systems, direct steam generating parabolic trough or trough with salt as a HTM

El Borma: solar evaporation and 

superheating

Methodology

• comparison of the annual fuel consumptions 43 kW ISCCS trough43 kW ISCCS tower43 kW CC conventional

• calculation of Fuel Save in the two ISCC• solar electricty = output of reference CC with saved fuel• time resolution: 1h

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‐ annual calculation in Greenius (DLR)

‐modeling of the CC with Ebsilon Professional‐ calculation of operating points ‐ interpolation for use in Greenius

‐meteoroloical data by Meteonorm

‐ lay‐out of the solar fields + receivers  ‐maximum solar thermal power: 20 MWth ‐ energ dumping 5% of solar thermal power)

Methodology

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Meteo data: DNI

DNI: 1814 kWh/m2/y

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Power Plant Flow Chart (Ebsilon)

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Calculation of the Operating Points (Ebsilon)

opertaing points defined by:  ‐ ambient temperatur 

‐ solar field thermal power 

‐ plant power

paramters calculated: 

‐ GT load 

‐ solar electrical power

‐ auxiliaries

- fuel consumption‐ feed water return   

temperatur (to solar 

field)

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Lay‐Out of the Solar Field: Parabolic Trough

solar field maximum thermal power: 20 MWth

data of Eurotrough II collector used

14 Loops 

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interpolation within implemented field models (dependent on thermal power and geographical lattitude)

Lay‐Out of the Solar Field: Heliostats

solar field maximum thermal power: 20 MWth

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field‐intercept                  31,3 MW

Receiver‐Intercept          26,6 MW

air outlet temperatur:    500°C

Lay‐Out of the Solar Field: Heliostats

solar field maximum thermal power: 20 MWth

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1. The El Borma Oil-Field and its Current Power Supply

3. Methodology

2. The Future Concept

4. Results

5. Conclusions

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Results I

trough tower

fuelsave MWhth 21883 21935

t 1575 1579

% 2,72 2,72

trough tower

solargeneratedelectricity

MWhel 10250 10273

% 2,72 2,73

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Results II

trough tower deviationtroughvs.tower

aperturearea m2 45780 46862 2,36%

mirrorarea m2 50458 46862 ‐7,13%

solarheatMWhth 39376 39036 ‐0,86%

fossilheatMWhth 783490 783439 ‐0,006%

dumping MWh 2001 2047 2,30%

groundareasolarfield ha 16 23 44%

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Conclusions

‐ no significant differnces tower/trough(fuel save, solar generated electricity)

‐ economic criteria, reliability and experience

‐ economic comparison difficult (small, young and discontinous cspmarkets)

‐ trough technology more mature but not with direct steam (one new commercial plant in Thailand + one test plant, Spain)

‐ significant difference: solar field size (not of major interest at this site)