DIRECT STEAM GENERATION USING

THE SG4 500m2 PARABOLOIDAL DISH

CONCENTRATOR

Greg Burgess, Keith Lovegrove, Scott

Mackie, Jose Zapata and John Pye

Solar Thermal Group, College of Engineering and

Computer Science

1980: White

Cliffs 14 x 20m2

dishes

1994: 400m2

SG3 Big Dish

1998:

400m2

System

for BGU

Israel

ANU Solar Thermal history

One off designs which

proved technical

feasibility of big solar

dishes

Cost optimisation says big is beautiful!

0

0.5

1

1.5

2

2.5

3

3.5

4

4.5

5

1 3 5 7 9

11

13

15

17

19

21

23

Dish Radius (m)

No

rma

lis

ed

co

st

/ u

nit

are

a Series3

Series6

Series9

Series12

Series1520%

30%

70%

Variation in R3

dependence

The Generation II Big Dish

• A new large aperture dish re-engineered for mass production and deployment in large arrays

• Aperture 494 m2 (489 m2 mirror)

• Focal length 13.4 m

• Average diameter 25 m

• Number of mirrors 380

• Total mass of dish 19.1 t

• Total mass of base and supports 7.3 t

• Mass per unit area ~ 40 kg/m2

• Electrical output in large system > 100 kW / dish

Photogrammetry of jig support points, +- 0.6mm

Coils of sheet

steel in….

Structural

sections out

On site section rolling machine

Installation of front surface members

Welding of spaceframe

Lifting of spaceframe

High accuracy interchangeable mirror

panels

Mirrors attached without adjustment

Mirror panels contribute to structure

First operation with all mirrors

Melting ceramic blanket at > 1400 oC

SG4 Full moon 4 Sep 2009 - image 35

0

10

20

30

40

50

60

70

80

90

100

0 0.1 0.2 0.3 0.4 0.5 0.6 0.7

Diameter (m)P

erc

en

t cap

ture

Relative

intensity

Lunar Flux

mapping

Target

dimensions in mm

• >2,000 suns at 95% capture

• >14,000 suns at peak

• Old SG3 dish only peaked at 1,500 suns

Monotube boiler steam receiver

Peak concentration ~ 14,000 x

On-sun operation

Peak concentration ~ 14,000 x

On-sun operation

Peak concentration ~ 14,000 x

operation up to 4.5MPa 535 oC

Temperature profile through receiver

Excellent receiver efficiency

Conclusions

• System “design for manufacture” of a Gen II Big Dish successfully completed

• World’s biggest solar dish

• Spherical interchangeable non-adjustable mirrors give excellent optical performance

• Monotube boiler DSG receiver successfully operated to 4.5MPa, > 500oC

• Receiver efficiencies consistently > 90%

• Suitable for a driving a range of energy conversion processes needing high levels of concentration

• The design is ready for large scale commercial roll out

Acknowledgements

Support from the Australian Government under the

Renewable Energy Development Initiative (REDI)

and the Australian Solar Institute (ASI) is gratefully

acknowledged