2. Seite 2Performance Modeling
Solar Millennium Group
Content
1. Performance Model
• PCTrough
• Solpipe
• Investment Cost Model
• O&M
• Solar Resource and Weather
• Thermal Electric Storage
• Transients – Start Up! Connects to Back Up Fuel
2. Validation with SEGS VI data
3. Validation with SkalET Demo Loop
3. Seite 3Performance Modeling
Solar Millennium Group
Flagsol’s Models
Excel-File:
Input Data Sheet
(Customer)
Excel-File:
„Basic Considerations/
Calculations“
Input by Customer and Flagsol
Fix Flagsol-Data:
-Collector-type
-Solarfield design
-Thermal Storage
Fix Supplier Data:
-Steam Turbine
-Power Block
-HTF-Fluid
-TES medium
Plant Configuration
Report
(Word-file)
DATABASE – RUN-File
(EXCEL-based)
Pictures from different
sources:
-Google Earth
-Visio
-Image Composer/Corel
Graphical User
Interface
(GUI)
LEC
(Excel-file)
O&M costs
(Excel-file)
Investment costs
(Excel-file)
PCTrough
(VBA-application)
Solpipe
(Excel-file)
4. Seite 4Performance Modeling
Solar Millennium Group
Input/Output data Performance Model
PCTrough
Performance Model
Input Output
Power Block Data
Storage Data
Solar Field Data
Weather Data
TMY
in 10 min. steps
- Electrical Output
- Auxiliary El.
Consumption
- Gas Consumption
Solpipe Model
5. Seite 5Performance Modeling
Solar Millennium Group
Solar Resource
Creating a Measured Typical Year (or P50/90
classification)
• Methodology – creates problem with an irregular year
(months)
Vs.
NREL TDY
• Conservative and missing higher intensity radiation and +/-
25%
6. Seite 6Performance Modeling
Solar Millennium Group
Satellite vs. Measured – A Common Trend
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Frequency–Hoursofthe8760inComparedYear
Irradiance - W/m^2
Yellow = Ground Measured Station
Blue = Satellite Model at Same Location
7. Seite 7Performance Modeling
Solar Millennium Group
Solpipe
Thermohydraulic model of collector loop and
solar field piping
Input Data:
• Design thermal power (@heat exchangers)
• Solar field inlet/outlet temperatures
• Topography of solar field (terraces)
Standard
pipe list
Equipment data
(vessels, pumps…)
Collector data
(HCE, Swivel joints…)
Output Data:
• Pressure drop
• HTF Pumping parasitic load
• Heat losses of header piping
• HTF volume
• Piping BOM (including elbows,
reducers, Tee-pieces….)
8. Seite 8Performance Modeling
Solar Millennium Group
Solpipe – Loop model
SKALET 150
HelioTrough (NTPro)
44,0m22,0m
191,0m 191,0m
410,0m
Input data:
• Mass flow per loop
• Temperature difference
(inlet/outlet)
• Collector data, HCE
data, Inter connecting &
cross over piping
• Swivel joints data
Output: data:
• Pressure drop
• Heat losses (without
HCE)
9. Seite 9Performance Modeling
Solar Millennium Group
PCTrough Structure
Definition of Project
(First Module)
Performance Simulation
(Second Module)
Results Generation
(Third Module)
Output
Steam Turbine
Power Block
Gas Turbine
WHRS
Heater
Storage
Solar Field
Collector
Optional Output to Screen
Calculation Loop
Hourly Results of
Production and
Subsystems Data
Operating
Strategy
Location
Data
Weather
Data
Design and Off-Design Parameters
Results of Performance
Run:Technical Data, Thermal
and Electrical Production with
Breakdown by Day, Tariff,
Month and Year, Revenues
Production Strategy to Meet Demand
Energy To/From Storage
Operate Gas Turbine,
Estimate WHRS Contribution,
Thermal Production by Heater/Boiler
Calculate Gross & Net Electric Production
Start Simulation, Initialize Data
Solar Thermal Production
Sum Up Results, Calculate Revenues and
Generate Report
Three modules:
• Definition of project
• Simulation
• Results
PCTrough calculates
• Solar field heat gain in
5 min steps
• Considers HTF travel
time, availabilities,
operation strategies…
11. Seite 11Performance Modeling
Solar Millennium Group
Thermal Energy Storage Module
Input data
Turbine Efficiency
Thermal Capacity of PB
Thermal Discharge Load
Solar Multiple
Thermal Storage Capacity
Approach Temperature of TES Heat Exchangers (HEX)
HTF HEX Inlet Temperature
HTF HEX Outlet Temperature
Output data
Cold/Hot Tank Temperature
Salt Mass (Active + Dead Volume)
Tank Dimension
Number of Tanks and Heat Exchangers
Charge/Discharge Mass Flow
TES Tool
Calculation
Example: Charge Mode
HEX
HTF
12. Seite 12Performance Modeling
Solar Millennium Group
Technical Parameters for Amargosa TES
• Type: three identical 2-tank systems
• Storage Capacity: 3800 MWh
• Storage Tank Size: 15 m height
34 m diameter
• Salt Mass: ~100 000 tons
• Heat Exchanger Arrangement: 2 parallel trains of 6 heat exchangers per
two-tank system
• Pumps: 2 pumps per tank
• Salt Flow Rate per Pump: ~370 kg/s
13. Seite 13Performance Modeling
Solar Millennium Group
Transient Module
Detailed Analysis of Cloud Transients and Start-up
Input: Solar Field, Heat Exchangers and Power Block Characteristics
Pipe Sizes, Isolation, Temp. Rise Gradients, Start-Up Procedures, etc.
Output: HTF and Water-Steam Conditions, Electrical Output
14. Seite 14Performance Modeling
Solar Millennium Group
Content
1. Performance Model
2. Validation with SEGS VI data
3. Validation with SkalET Demo Loop
15. Seite 15Performance Modeling
Solar Millennium Group
Comparison of Model and SEGS VI
Monthly Solar Field Output [MWhth], 2000
PCTrough vs. SEGS VI Data
116%
109%
101%
99%
99%
98%
100%
99%
99%
97%
96%
97%
0
5000
10000
15000
20000
25000
30000
35000
40000
Jan Feb Mrz Apr Mai Jun Jul Aug Sep Okt Nov Dez
MonthlySolarFieldOutput[MWhth]
0%
Modell
SEGS VI
16. Seite 16Performance Modeling
Solar Millennium Group
Comparison of Model and SEGS VI
Monthly Gross Electricity Production in MWhe
PCTrough vs. SEGS VI Data
99%
101%
100%
99%
99%
100%
99%
102%
101%
101%
102%
103%
0
2000
4000
6000
8000
10000
12000
14000
16000
Jan Feb Mrz Apr Mai Jun Jul Aug Sep Okt Nov Dez
MonthlyGrossElectricityOutput[MWhe]
0
1
Modell
SEGS VI
17. Seite 17Performance Modeling
Solar Millennium Group
Comparison of Model and SEGS VI, thermal
Example: blue sky day
Solar Field output [MWth]
PCTrough vs. SEGS VI Data
Date: 01.04.2000
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60
80
100
120
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Hour
solarfieldoutput
[MWth]
0
200
400
600
800
1000
1200
NormalDirect
Irradiation[W/m²]
Q_solar Model
Q_solar SEGS VI
NDI
18. Seite 18Performance Modeling
Solar Millennium Group
Comparison of Model and SEGS VI, thermal
Example: cloudy day
Solar Field output [MWth]
Flagsol model vs. SEGS VI Data
Date: 13.04.2000
0
20
40
60
80
100
120
0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23
Hour
solarfieldoutput
[MWth]
0
200
400
600
800
1000
NormalDirect
Irradiation[W/m²]
Q_solar Model
Q_solar SEGS VI
NDI
19. Seite 19Performance Modeling
Solar Millennium Group
Solar Field Output: Comparison of daily sum
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200
400
600
800
1000
1200
0 200 400 600 800 1000 1200
Calculated Thermal Output [MWh]
ActualThermalOutput[MWh]
Daily Solar Field Output [MWhth]
SEGS VI vs. model output
R2
= 0.9847
20. Seite 20Performance Modeling
Solar Millennium Group
Plant Gross El. Output: Comparison of daily
sum
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100
200
300
400
500
600
0 100 200 300 400 500 600
Calculated Gross Output [MWh]
ActualGrossOutput[MWh]
R² = 0.9923
21. Seite 21Performance Modeling
Solar Millennium Group
Content
1. Performance Model
2. Validation with SEGS VI data
3. Validation with SkalET Demo Loop
22. Seite 22Performance Modeling
Solar Millennium Group
In April ’03 the SKAL-ET Demonstration Loop at
KJC Operating Company was commissioned
Since then it is operated as a matter of routine as an
integral part of the commercial power plant SEGS V
23. Seite 23Performance Modeling
Solar Millennium Group
Results - Loop Efficiency (May 19, 2005)
0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
6:00 8:00 10:00 12:00 14:00 16:00 18:00
Time
Efficiency
0
100
200
300
400
500
600
700
800
900
1000
DNIinW/m²
Efficiency stationary
Efficiency model
DNI
24. Seite 24Performance Modeling
Solar Millennium Group
Results – Loop Efficiency 2005
0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
Jan Feb Mrz Apr May Jun Jul Aug Sep Oct Nov Dec
month
SKAL-ETloopefficiencies
measured efficiency
model efficiency
27. Seite 27Performance Modeling
Solar Millennium Group
Comparison of Model and SEGS VI
Conclusion
PCTrough is able to predict the performance of a SEGS
plant with an accuracy of ~1%
