peter heller presentation

Folie 1 > <Curso Ciemat, Madrid 25.10.2012 > P.Hellerr

Parabolic Dishes

Peter Heller, DLR

Dokumentname > Discos Heller Madrid Part 1 25.10.2010

Folie 2 > Curso Ciemat Madrid > P.Heller

HistoryHistory

1816 Robert Stirling obtains the patent

„Air Motor“

1872 John Ericsson constructs first Stirling Motor driven by solar energy

1984 The system Dish/Stirling Vanguard of 25-kWel achieves 29,4% efficiency (solar to electric energy)



Types of ConcentratorsTypes of Concentrators

Solar towerParabolic trough

Concentration factor 50-100 500-1000 3000-5000

Operation temperature300-400 °C 550-1000 °C 700-1200 °C

Paraboloid



STIRLING CycleSTIRLING Cycle

3

2

1

Pres

sur

e

Volume

Entropie

Tem

pera

ture

12

3 4

1

41-2 Compression

2-3 Displacement (V = const.)

3-4 Expansion

TH

TK

TH

4-1 Displacement

TL



PHI

0° 90° 180° 270° 360°

(1) (2) (3)(4) (4)

V

V

V

E

K

S

Expansions-raum

Regenerator

Kompressions-raum

DiskontinuierlicheKolbenbewegung

KontinuierlicheKolbenbewegung

Volume Change in Real Stirling ProcessVolume Change in Real Stirling Process

Expansion Cylinder

Compression Cylinder

Recuperator

Continuouspiston

movement

Discontinuouspiston

movement



The real Stirling processThe real Stirling process

Why does the real and theoretical process not coincidate?

1. Realización de movimiento discontinuo de pistón casi imposible

3. Rendimiento del regenerador < 100%4. Efecto „Dead Volume“

6. Perdidas de calor atravez del material

2. Etapa isotérmica casi imposible por la alta velocidad del gas

V

QKühler

ErhitzerQp

1

2

3

4

5. Perdida interna por disipación por• perdida de carga • gas real• rozamiento

V

QKühler

ErhitzerQp

1

2

3

4

Real Stirling process



- stop of expansion piston during compression- stop of compression piston during expansion

=> (theor.) acceleration of piston infinite=> Inertia extremely high (piston punch, noise, durability)

Conditions for control of discontinuous movements of piston :

The real Stirling processThe real Stirling process



SOLO STIRLING 161 SOLARSOLO STIRLING 161 SOLAR

Absorber

Gas cooler

Gas buffer

Crankcase

Compresion

Cylinder

Expansion Cylinder

Recuperator



Motor STIRLINGMotor STIRLING

ηth,St = 1 - TT3

1

Recuperator

Gas Cooler

ExpansionCylinder

Compresion Cylinder

Receiver



Efficiency CalculationsEfficiency Calculations

altengrecconcgrossconv ηηηηη ⋅⋅⋅=,Efficiency total gross:

φρθη ⋅⋅⋅= iconc E cosConcentrator:

appnb

parasiticsgrossconvnetconv AI

P⋅

−=,

,, ηηEfficiency net:

( ) ( )nbgconc

ambrecambrecrec ICR

TTFTTU

,

44

⋅⋅−⋅⋅+−⋅

−⋅=η

σατηReceiver:



Historical Evolution

Stirling motorsUnited Stirling AB 4-95Stirling Thermal MotorsUSAB / SOLO V160 (Stirling 161)Cummins (free piston)Infinia (free piston)…



- heat transfer coefficient should be high⇒

requieres high gas velocities, reduced dimensions ⇒

Pressure drop increased- Temperature difference exterior/interior should be small

⇒

requieres large surfaces ⇒

dead volumen increased

- Properties of materials limit upper cycle temperature

Components: Heat exchanger (receiver)Components: Heat exchanger (receiver)



Materials

• hight heat capacity• small dead volume• large internal surface• low friction and pressure losses• low axial heat conduction

Requirements:

Objective:recuperate heat from isochorous cycle

Components : RecuperatorComponents : Recuperator



Expansion Cylinder

- Unlubricated pistons- Pistons seals problematical due to radial

forces, pressure and lack of lubrification

- Expansion Cylinder:

• filled with insulation• thin walled, long (conduction)

(convection/radiation)• material: hight strenght, λ small

• Internal pressure• Orifices for pressure compensation

- Protection against deformation:

• Internal reinforcements

=> Fundamental difficulty !!!

Components : CylinderComponents : Cylinder



Concentrator DesignsConcentrator Designs

ShellMembrane Facets



Kinematic Motor of 4 cylindersKinematic Motor of 4 cylinders

Kinematic Motor4 cylinders4x95cm³ displacementDouble actionPower 25kWelHydrogen720°C, 20MPa41% efficiency



Free Piston StirlingFree Piston Stirling

Recuperator

Receiver

Gas Cooler

Compresion Cylinder

Expansion CylinderLinerar

Generator

Free piston6 (9) kWelHelium630°C4MPaEfficiency 33%

CPG:



Konzentrator Schale

Elevations Lager

Ringträger

SchaltschrankS

Stirling Einheit

Stirling Tragwerk

Drehstand

AntriebsschieneAzimut

FundamentAzimuthantrieb

AntriebsschieneElevation

Concentrator Shell

Stirling Motor

Stirling Support

Turn Table

Rail Azimuth

FoundationAzimuth Drive

Elevation Bearing

Ring Truss

Elevation Rail

Control Cabinet

Schematic of EURODISH-SystemSchematic of EURODISH-System



Concentrator ShellConcentrator Shell



FEM Calculation

Temporary RipsTemporary Rips



SOLO STIRLING 161 SOLARSOLO STIRLING 161 SOLAR

Blower (peak)

Generator

Stirling

ReceiverCavity Aperture

Cooling System



Diseño y Construcción de Cavidad CeramicaDiseño y Construcción de Cavidad Ceramica



Motors (tracking and emergency)

Motors (tracking and emergency)



Control CabinetControl Cabinet



Typical Power OutputTypical Power Output



CavityConcentrator Stirling Engine

Generator

Shading,Reflectivity

Blocking Reflection ConvectionConduction

Thermal Output

DissipationIR-Emission

Sun Electr.

ThermalLosses

EURODISH EfficiencyEURODISH Efficiency

84,5 % 39,4 % 92,5 %74,4 %

22,5 %Syxstem efficiency solar to electric:



Solar FluxSolar Flux

9500 -- 10000 9000 -- 9500 8500 -- 9000 8000 -- 8500 7500 -- 8000 7000 -- 7500 6500 -- 7000 6000 -- 6500 5500 -- 6000 5000 -- 5500 4500 -- 5000 4000 -- 4500 3500 -- 4000 3000 -- 3500 2500 -- 3000 2000 -- 2500 1500 -- 2000 1000 -- 1500 500 -- 1000 0 -- 500

Flux Density [kW/m2]0

025005000750010000

Flux

Den

sity

y-C

ut[k

W/m

2 ]

x-Axis [mm]

025

0050

0075

0010

000

0

Flux Densityx-Cut

[kW/m2]

y-Ax

is [m

m]

Flux Density [kW/m2]

1600 -- 1700 1500 -- 1600 1400 -- 1500 1300 -- 1400 1200 -- 1300 1100 -- 1200 1000 -- 1100 900 -- 1000 800 -- 900 700 -- 800 600 -- 700 500 -- 600 400 -- 500 300 -- 400 200 -- 300 100 -- 200 0 -- 100

0

0500100015002000

Flux

Den

sity

y-C

ut[k

W/m

2 ]

x-Axis [mm]

050

010

0015

0020

00

0

Flux Densityx-Cut

[kW/m2]

y-Ax

is [m

m]

Aperture Absorber



MotivationMotivation

Distributed Systems:

25 kW SES10 kW EURODISH

6 units, Europe 66 units, USA

3 kW Infinia60 units, USA30 units, España

Why?

Systems in the market :

- Potential for mass production

- Potential for hybridization

=> Cost reduction

- Distributed market of high value

- Low economic risk

- Quick implementation



Comparision Sistemas Disco/Stirling (2005)Comparision Sistemas Disco/Stirling (2005)

25 kW SES/Boing

22 kW SunDish

10 kW EURODISH

10 kW ADDS

- Comparitive Study realized in 2005 (Mancini, Heller et al)



Comparison Dish/Stirling Systems (2005)Comparison Dish/Stirling Systems (2005)



Comparison Sistemas Disco/Stirling (2005)Comparison Sistemas Disco/Stirling (2005)



EURODISH Country Reference UnitsEURODISH Country Reference Units

CRU in Milano/Italy CRU in Seville/Spain

CRU in Würzburg/Germany CRU in Odeillo/France



Location Country Reference UnitsLocation Country Reference Units

CRU Sevilla

CRU Würzburg

CRU Milan

CRU Odeillo

Test bed Almeria


Folie 34 > Sollab Summerschool Almeria > P.Heller

0

50

100

150

200

250

09:00 11:00 13:00 15:00 17:00 19:00Time

Pres

sure

[bar

], Po

wer

[kW

], Ef

fic. [

%]

100

200

300

400

500

600

700

800

900

1000

Irrad

ianc

e [W

/m²],

Tem

pera

ture

[°C

]

Engine PressureBottle PressureGross Power * 10Gross Efficiency * 10Max. Receiver Temperatur Direct Beam Insolation

07:00

Performance chart – sunny winter dayPerformance chart – sunny winter day



Input / Output characteristic – sunny winter dayInput / Output characteristic – sunny winter day

0

50

100

150

200

250

09:00 11:00 13:00 15:00 17:00 19:00Time

Pres

sure

[bar

], Po

wer

[kW

], Ef

fic. [

%]

100

200

300

400

500

600

700

800

900

1000

Irrad

ianc

e [W

/m²],

Tem

pera

ture

[°C

]

Engine PressureBottle PressureGross Power * 10Gross Efficiency * 10Max. Receiver Temperatur Direct Beam Insolation

0

2

4

6

8

10

12

0 100 200 300 400 500 600 700 800 900 1000Direct Beam Insolation [W{m²]

Gro

ss P

ower

[kW

]

Start up in the morningShut down in the evening



Expected System CostExpected System Cost

0

20.000

40.000

60.000

80.000

100.000

120.000

140.000

1 10 100 1000Systems per year

Euro

per

10

kW U

nit

Overhead TransportationSite assemblingProject handlingComponent cost

Without any component improvement or other technical advances



10.000

20.000

30.000

40.000

50.000

60.000

70.000

80.000

90.000

100.000

1 10 100 1000Units per year

Euro

per

uni

t

StirlingElectricsConcentratorMachined partsSteel parts

Expected Component Cost



Expected Levelized Energy Cost

Sites in South Europe

Sites with excellent solar insolation

1 10 100 1000

Units per year

0,00

0,10

0,20

0,30

0,40

0,50

0,60

0,70

0,80

0,90

Euro

/ kW

h

Interest rate: 6%Depreciation period: Dish-Stirling: 12 yearsDiesel: 15 yearsPV: 20 years

O&M Cost: D-S and Diesel: 2%PV: 1%

PVtoday – 6,5 T€/kWPVtoday – 5,5 T€/kW

Diesel gen set: 0,40 €/lDiesel gen set: 0,60 €/lDiesel gen set: 0,80 €/lDiesel gen set:1,00 €/l

Dish-Stirling

PV with cost reduction



10 kW Prototype at KIER, KoreaPrototype 2007SOLO 161120 reflectors, 5 curvatures, 1mm mirror clued onto aluminium structure40,3 m² projected reflector area2 motors for trackingEfficiency : 20,2% peak



Infinia Corporation, EEUUInfinia Corporation, EEUU

Investment: $100 million venture capital

Data:3 kWe, 24% efficiencyFree PistonMirrors: SolFocus, Mountain View

Prototype Plants:6 kW, Kennewick, Wa, EEUU6 kW, Sandia National Labs, Albuquerque, NM, EEUU9 kW, Belen, NM, EEUU15 kW, Kennewick Toyota Center, EEUU40 kW, Richland, EEUU

Development:Storage (molten salt) (R&D proyect, $3m, DOE)



Second generation Infinia system6 months of implementaion (24 months for other technologies)Efficiency 24% (peak)Reflectors: RioglassMaterials: auxiliar sector automotive 1 MW Planta Casa del Ángel, Casas de los Pinos, Cuenca, España71 MW pre-assigned

Renovalia (Spain)Renovalia (Spain)



SES „SunCatcherTM“SES „SunCatcherTM“



SESSES

50.000 hours of solar operation (motor), 120.000 hours dishefficiency: 30%Significant improvements in design of motor6 dishes at SANDIA, NM, EEUU



Tessera Solar InternationalPower company (BOO)May 2008: $100 million for system optimisation (NTR, Irlandia)Improved design of facetsCapital cost: 3.000 $/kWTarget LEC: $ 0,2 per kWh55.000 - 60.000 kWh/yrImperial Valley Solar and Calico Solar (70.000 SunCathersTM, 1.550 MW), CA, EEUU1.5 MW demo plant (60 SunCathersTM, ) en Maricopa County, Phoenix, AZ, EEUU

SES „SunCatcherTM“SES „SunCatcherTM“

STATUS: Insolvency



Proposal of Demo Plant EURODISHProposal of Demo Plant EURODISHPower: 500kW – 1 MW (50 – 100 units)Investment cost: approx. 4 millons €Location: Spain

Expected Results:Cost reductionImproved O&MSerial productionproven technology



Conclusion EURODISHConclusion EURODISH

Functional testsImplementation improvements (cavity etc,)Remote control Demonstration of high availability (>90%)Verification of high performance (>21%)

Results:

Next steps:

Demonstration plant de 500kW – 1 MWSerial productionTechnology transferDevelopment of hybrid systemDevelopment of remote system

SBP y Cleanergy (SOLO) develop parallel systems based on Eurodish



Conclusión SESConclusión SES

Incorporated improvementsDemonstration of high availability Verification of high performance 6 prototipos in Albuquerque Power Purchase Agreements 1 MW constructed en Arizona

Results:

Next steps:

Establishment of serial productionConstruction of first bulk power plants (500 MW)

Situation unclear after insolvency of SES



SummarySummary

High efficiencyLearning curve => high costCompetition with cheap PVStorage/dispatchability missingNo specific feed-in tariffMost players are disappearing due to market situation



Thank you for your attention !

peter heller presentation

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