Performance Presentation - NREL March 2010

Solar Millennium Group

Performance Modeling

Daniel Benitez, Jake McKee

National Renewable Energy Laboratory

Golden, CO

March 2nd 2010

Seite 2Performance Modeling


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



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)



Input/Output data Performance Model

PCTrough Performance Model

Input Output

Power Block Data

Storage Data

Solar Field Data

Weather DataTMY

in 10 min. steps

- Electrical Output - Auxiliary El.

Consumption- Gas Consumption

Solpipe Model



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%



Satellite vs. Measured – A Common Trend

25 75 125

175

225

275

325

375

425

475

525

575

625

675

725

775

825

875

925

975

1025

1075

0

50

100

150

200

250

300

350

Irradiance - W/m^2

Fre

qu

ency

– H

ou

rs o

f th

e 87

60 i

n C

om

par

ed Y

ear

Yellow = Ground Measured StationBlue = Satellite Model at Same Location



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….)



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)



PCTrough Structure

Definition of Project (First Module)

Performance Simulation (Second Module)

Results Generation (Third Module)

Output

Steam Turbine

Power BlockGas Turbine

WHRS

Heater

Storage

Solar Field

Collector

Optional Output to Screen

Calculation LoopHourly Results ofProduction and

Subsystems Data

OperatingStrategy

LocationData

WeatherData

Design and Off-Design Parameters

Results of PerformanceRun:Technical Data, Thermaland Electrical Production with

Breakdown by Day, Tariff,Month and Year, Revenues

Production Strategy to Meet DemandEnergy To/From Storage

Operate Gas Turbine,Estimate WHRS Contribution,

Thermal Production by Heater/BoilerCalculate Gross & Net Electric Production

Start Simulation, Initialize Data

Solar Thermal Production

Sum Up Results, Calculate Revenues andGenerate 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…



Solar field Input data

SOLPIPE data(Thermohydraulic Model of Solar Field Piping)



Thermal Energy Storage ModuleInput data

Turbine EfficiencyThermal Capacity of PBThermal Discharge LoadSolar MultipleThermal Storage CapacityApproach Temperature of TES Heat Exchangers (HEX)HTF HEX Inlet TemperatureHTF HEX Outlet Temperature

Output dataCold/Hot Tank TemperatureSalt Mass (Active + Dead Volume)Tank DimensionNumber of Tanks and Heat ExchangersCharge/Discharge Mass Flow

TES ToolCalculation

Example: Charge Mode

HEX

HTF



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



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



Content






Comparison of Model and SEGS VI

Monthly Solar Field Output [MWhth], 2000PCTrough 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

Mo

nth

ly S

ola

r F

ield

Ou

tpu

t [M

Wh t

h]

0%

Modell

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

Mo

nth

ly G

ross

Ele

ctri

city

Ou

tpu

t [M

Wh e

]

0

1

Modell

SEGS VI



Comparison of Model and SEGS VI, thermal

Example: blue sky day

Solar Field output [MWth]PCTrough vs. SEGS VI Data

Date: 01.04.2000

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

sola

r fi

eld

ou

tpu

t [M

Wth

]

0

200

400

600

800

1000

1200

No

rmal

Dir

ect

Irra

dia

tio

n [

W/m

²]

Q_solar Model

Q_solar SEGS VI

NDI



Comparison of Model and SEGS VI, thermal

Example: cloudy daySolar Field output [MWth]

Flagsol model vs. SEGS VI DataDate: 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

sola

r fi

eld

ou

tpu

t [M

Wth

]

0

200

400

600

800

1000

No

rmal

Dir

ect

Irra

dia

tio

n [

W/m

²]

Q_solar Model

Q_solar SEGS VI

NDI



Solar Field Output: Comparison of daily sum

0

200

400

600

800

1000

1200

0 200 400 600 800 1000 1200

Calculated Thermal Output [MWh]

Act

ual T

herm

al O

utpu

t [M

Wh]

Daily Solar Field Output [MWhth]SEGS VI vs. model output

R2 = 0.9847



Plant Gross El. Output: Comparison of daily sum

0

100

200

300

400

500

600

0 100 200 300 400 500 600

Calculated Gross Output [MWh]

Act

ual

Gro

ss O

utp

ut

[MW

h]

R² = 0.9923



Content






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



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 18:00Time

Eff

icie

ncy

0

100

200

300

400

500

600

700

800

900

1000

DN

I in

W/m

²

Efficiency stationaryEfficiency modelDNI



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 Decmonth

SK

AL

-ET

lo

op

eff

icie

nci

es

measured efficiency

model efficiency



Results - Loop Thermal Output




Conclusion

PCTrough is able to predict the performance of a SEGS plant with an accuracy of ~1%



Future Knowlegde

Validation with HelioTrough Demo Loop coming

soon…



Thank you

Performance Presentation - NREL March 2010

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Transcript of Performance Presentation - NREL March 2010