Next Generation Technologies for solar thermal electricity production

Robert Pitz-Paal, DLR

Slide ٢ > Solar Research> Pitz-PaalEgypt > 11/12.10.2007

Direct Solar Steam Generation

Slide ٣ > Solar Research> Pitz-PaalEgypt > 11/12.10.2007

Direct Solar Steam Generation Thermo-hydraulics

Blasen Ring WellenSchwallWasser Dampf

Slide ٤ > Solar Research> Pitz-PaalEgypt > 11/12.10.2007

Dampfmassenstrom

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

10.50 11.00 11.50 12.00 12.50 13.00 13.50 14.00 14.50 15.00 15.50

Zeit

Mas

sens

trom

[kg/

s]

Druck Kollektoreintritt

30

32

34

36

38

40

42

10.50 11.00 11.50 12.00 12.50 13.00 13.50 14.00 14.50 15.00 15.50

Zeit

Dru

ck [b

ar]

Direktstrahlung

0

100

200

300

400

500

600

700

800

900

1000

10.50 11.00 11.50 12.00 12.50 13.00 13.50 14.00 14.50 15.00 15.50

Zeit

DN

I [W

/m^2

]

Eintrittsmassenstrom

0

0.2

0.4

0.6

0.8

1

1.2

1.4

1.6

10.50 11.00 11.50 12.00 12.50 13.00 13.50 14.00 14.50 15.00 15.50

Zeit

Mas

sens

trom

[kg/

s]

Testsignale

Direct Solar Steam Generation Control

Fee...mh pLife...mh p

K...n

S...1

Life...mh p

K...n Pi... Pi... Pi...K...n Pi... K...n Pi... K...n Pi...

Inj...1

Wa...mh p

Inj...1

Life...mh p

Dynamisches Modell

Slide ٥ > Solar Research> Pitz-PaalEgypt > 11/12.10.2007

Direct Solar Steam Generation Control

300

320

340

360

380

400

420

11 13 15 17 19 21Zeit in h

Tem

pera

tur i

n °C

0

20

40

60

80

100

120

Dru

ck in

bar

, D

irekt

stra

hlun

g in

W/m

^2/1

0

TemperaturDruckDirektstrahlung

Slide ٦ > Solar Research> Pitz-PaalEgypt > 11/12.10.2007

Direct Solar Steam Generation Component Optimization

Absorber Tube (Temperature Image through glassenvelope)

Compact-Steam Seperators

Slide ٧ > Solar Research> Pitz-PaalEgypt > 11/12.10.2007

Direct Solar Steam Generation Qualification

Measurement

Ray-TracingFlux distribution next to absorber tube

Slide ٨ > Solar Research> Pitz-PaalEgypt > 11/12.10.2007

Direct Solar Steam Generation Latent Heat Storage Technology

Latentspeicherung durch Phasenwechsel in der Salzschmelze

D r

solid

liquid

Fluid

Slide ٩ > Solar Research> Pitz-PaalEgypt > 11/12.10.2007

Direct Solar Steam Generation System Optimization

Slide ١٠ > Solar Research> Pitz-PaalEgypt > 11/12.10.2007

A few words on Linear Fresnel Systems

The Linear Fresnel DesignMore simple design offers potentially lower investment costLower optical efficiency compared to parabolic troughsTherefore, high optical accuracy required

Solarmundo

DLR Solarmundo SHP - MAN

Slide ١١ > Solar Research> Pitz-PaalEgypt > 11/12.10.2007

Slide ١٢ > Solar Research> Pitz-PaalEgypt > 11/12.10.2007

Annual collector eff. = 37%

Annual Turbine eff = 25%Fresnel Total Annual Eff. = 9%Trough/Tower > 15%

Slide ١٣ > Solar Research> Pitz-PaalEgypt > 11/12.10.2007

Rankineη = 16 % (annual)

Rankineη = 16 % (annual)

CCη = 25 % (annual)

The Solar Gas Turbine Approach

Slide ١٤ > Solar Research> Pitz-PaalEgypt > 11/12.10.2007

Experimental Experience at the PSA

gas turbine

NT Module

generator

MT/HT Module

MT Module

Slide ١٥ > Solar Research> Pitz-PaalEgypt > 11/12.10.2007

Experimental Experience at the PSAusing a small gas turbine

Feasibility shown how to integrate solar high temperature heat at 800°C; 7 bar into a gas turbineSolar share up to 68%Good controllability at fluctuating irradiationReceiver exit temperature of >1000°C demonstratedPerformance figures of design tools confirmed

Slide ١٦ > Solar Research> Pitz-PaalEgypt > 11/12.10.2007

227 MWth

-1000

-500

0

500

1000

1500

-1500 -1000 -500 0 500 1000 1500

Entfernung nach Westen [m]

Entfe

rnun

g na

ch N

orde

n [m

]

Long-term concept for a solar-fossil Combined-Cycle

1250°CGas turbine inlet temperature

220,0mOptical tower height

41.4%Annual solar to heat eff.

227’000kWthtotal receiver power

572number of rec. modules

734,4m²total receiver aperture

1,28m²aperture of single module

1100°Crec. outlet temperature (DP)

499’495m²Total reflective area

2379-number of heliostats

880W/m²solar input (DP)

Solar-System

49.4/52.2% Annual power cycle efficiency

158’900kWe (DP)Total Power (design point DP)

62’400kWe (ISO)Steam turbine

2 * 60’533kWe (ISO)Gas turbine (2 * V64.3)

Power block

Slide ١٧ > Solar Research> Pitz-PaalEgypt > 11/12.10.2007

Additional Investment Solar Reference

Site preparation [T€] 4.495

Buildings [T€] 300 125

Electrical equipment [T€] 250 100

Auxiliary equipment [T€] 150 50

Total [T€] 5.195 275

Indirect cost

Construction (9%) [T€] 17.463 8.174

Management (10%) [T€] 19.403 9.083

Contingencies (3.5%) [T€] 7.761 3.633

Total [T€] 42.062 17.532

Total [T€] 236.095 108.357

Specific (related to. DP-power) [€/kWe] 1.486 682

Cost assumptions Investment

„Levelized Electricity Cost (LEC)“ based on IEA methodInterest rate 7%Depreciation time 20 asite Barstow (California, USA)Annual direct irradiation 2791 kWh/m²aFuel price varied (today arround17 €/MWh in US)

Power cycle Solar Reference

Power cycle [T€] 88.300 81.800

Fuel system [T€] 6.500 6.500

Grid connection [T€] 2.250 2.250

Total [T€] 97.050 90.550

Specific (related to. DP-power) [€/kWe] 611 570

Solar-System

heliostat field (125€/m²) [T€] 62.437

tower (220 m) [T€] 4.475

receiver (35 T€/m²) [T€] 23.876

control [T€] 1.000

Total [T€] 91.788 -

Specific [€/kWth] 404 -

Slide ١٨ > Solar Research> Pitz-PaalEgypt > 11/12.10.2007

LEC in Mid-load Operation

4000 full-load hours

0,00

0,01

0,02

0,03

0,04

0,05

0,06

0,07

0,08

0,09

0,10

0 5 10 15 20 25 30 35 40

Fuel price [€/MWh]

LEC

[€/k

Wh]

Reference

Hybrid

0€/t CO2; 7% interst20 years125€/m² Heliostat

44% solar share

Solar LECSolar LEC

Slide ١٩ > Solar Research> Pitz-PaalEgypt > 11/12.10.2007

Impact of CO2-penalties, interest rate and heliostat cost

4000 full-load hours

0,00

0,01

0,02

0,03

0,04

0,05

0,06

0,07

0,08

0,09

0,10

0 5 10 15 20 25 30 35 40

Fuel price [€/MWh]

LEC

[€/k

Wh]

Reference

Hybrid

20€/t CO2; 5% interst20 years100€/m² Heliostat

44% solar share

Solar LECSolar LEC

Slide ٢٠ > Solar Research> Pitz-PaalEgypt > 11/12.10.2007

How to go there…

cost of solar electricity as function of solar system size

0.00

0.05

0.10

0.15

0.20

0.25

0 20 40 60 80 100 120 140 160 180 200 220 240

receiver thermal power [MW]

sola

r LEC

[€/k

Wh]

small systems (1-30 MWth)big systems (60-230MWth) north fieldbig systems (60-230MWth) multi aperturetrend

160 MWe CCsolar share:

80% DP 44% annual

Slide ٢١ > Solar Research> Pitz-PaalEgypt > 11/12.10.2007

Summary

High efficient solar power plant for mid-load power Solar-to–electric efficiencies > 20%Fuel-to-electric efficiency > 50%

Low environmental profile25% of cooling water compared to parabolic trough plantNo thermal oil!Can be applied in hilly area

Low costSpecific investment cost <1500 €/kWeLEC = 7 €cent/kWh for 160 MWe power plant

Scale-up Starting with small turbines (eventually combined with CHP)Hybridization with Biofuel (up to 50% feasible in Spain)

Slide ٢٢ > Solar Research> Pitz-PaalEgypt > 11/12.10.2007

Thank you for your attention!