El papel de la química en el desarrollo de la energía solar termoeléctrica By Luis Alberto Solá Paños. Schott Solar SL

1. SOLAR
Innovations @Schott - contributions
to a competitive Parabolic Trough
technology
Luis Alberto Solá Paños
SCHOTT Solar SL
EL PAPEL DE LA QUÍMICA EN EL DESARROLLO DE LA ENERGÍA SOLAR TERMOELÉCTRICA
EXPOQUIMIA, Barcelona, Nov. 18, 2011

2. SOLAR
The Challenge: Cost reduction
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3. SOLAR
The Task for SCHOTT Solar:
• Economies of scale and cost cutting in production
• Increasing the efficiency of the receiver component:
- improved coatings for higher optical efficiency
- increased aperture
p
- larger component
- higher operating temperature for new heat
transfer fluids
• Increasing reliability
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4. SOLAR
Economies of Scale - SCHOTT Solar Production Sites
More than 600.000 Receivers already delivered to power plants around the globe
Mainz (Germany)
Headquarter
Mitterteich
Production i
P d ti since August 2006
A t
Capacity: 200 MW p.a.
Pilot line for new products
Seville (Spain)
Albuquerque (USA) Production since March 2008
Production since April 2009 Capacity: 400 MW p.a.
Capacity: 400 MW p.a.
standardized production and release processes across all sites
best-practice and know-how transfer
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5. SOLAR
Towards higher Operating Temperatures
Today : HTF: Synthetic Oil with limited operating temperture (400°C)
Average annual efficiency 12-13%
New heat transfer fluids
to increase operating temperature
p g p
and hence increase efficiency and reduce cooling load
Direct steam generation: Molten salt Improved Synthetic Oil
• temperatures > 500°C • temperatures > 500°C • temperatures > 400°C
• efficiency >15% • efficiency >15% • efficiency >13%
• cheaper HTF • Storage • less hydrogen
Solar Only: New salts required to Limited efficiency gain
- with storage more ex-
g - reduce freezing risk
g
pensive than oil = safe operation and Cost: open
- without storage not - to reduce parasitic
competitive against PV losses
→ Potential niche market
for hybrid solutions Cost: open
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6. SOLAR
Is Molten Salt a good HTF for Parabolic Troughs?
g g
Under Investigation in indoor and outdoor test facilities:
corrosion
bending of absorber tubes
Cooling curve
freeze and thaw tests with single and
multiple receivers
Test of drainage scenarios and recovery
from freeze event
qualification of absorber coatings for
operating tempetatures up to 550°C Phase
change
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7. SOLAR
Increasing the Operating Temperature
What is the upper temperature limit for the absorber?
Answer important for operation and accelerated ageing test
Minimum Ageing
ageing time [h] temperature [°C]
1050 510
643 525
295 550
93 590
16 660
6 700
2 750
Limit (?)
Calculated acceleration factors as a function of For a simulated 25 year lifetime and activation
ageing test temperature for different activation energy of 170 kJ/mol calculated minimum ageing
energies (operative temperature 400 °C) testing time (operating temperature 400 °C)
© Copyright 2011 SCHOTT Solar CSP GmbH, All Rights Reserved

8. SOLAR
Test result for 590 °C test temperature
p
accelerated aging @ 590°C for operative temperature of 400°C
Emittance@400°C
10
97,5 Absorptance
9
97,0
Absorptanc [%]
Emitt
8
ce
tance [%]
96,5
7
96,0
96 0
A
6
25 years 25 years 25 years lifetime
95,5 lifetime lifetime 500°C will be
400°C 450°C reached at 4850h
5
0 500 1000 1500 2000 2500 3000 3500 4800
Overall aging time [h]
© Copyright 2011 SCHOTT Solar CSP GmbH, All Rights Reserved

9. SOLAR
Solutions for the Hydrogen Problem
Problem:
Thermo oil decomposes during operation,
hydrogen is generated.
Hydogen permeation through steel absorber tube
Getter secures vacuum
After saturation of Getter heat losses are
increasing rapidly
Glass
vacuum
H2 Getter
Steel tube
oil
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10. SOLAR
Noble Gas Capsule
• located in the glass annulus of the receiver
opposite to the mirror side
• to be opened non-invasive by a laser device
• unique solution for the ´hot tube
phenomenon
phenomenon´
Enhancing the live time:
- Th h ld glass t
Threshold l temperature i di
t indi-
cates increased thermal losses
- release of noble gas by opening the
capsule with a single laser pulse
- thermal losses will be immediately
reduced
© SCHOTT Solar CSP GmbH
© Copyright 2011 SCHOTT Solar CSP GmbH, All Rights Reserved

11. SOLAR
Noble gas Capsule – How it works
g p
capsule activation (2) can save more than 4000 W per receiver (1)
initial end of getter Hydrogen filling Capsule
state
t t capacity
it the
th vacuum activation
ti ti
5.7x
5 7x
5.7x
H2
H2
1
2Xenon
X
relative
relative capsule
heatheat activation
lossloss
1.3x
1 3x
1x 1.3x
Xe/H 2
1x Xe/H2
PTR70®
PTR70® (vacuum)
(vacuum)
initial time time
state 20-25 several following
years weeks years
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12. SOLAR
Shield Reflectors
designed to enhance receiver efficiency
REFLECTOR SHIELDS:
- Cover and insulate space
between receivers
- Reflector to use radiation
hitting the shielded area
- gains depend on incident
angle of irradiation
Illustration of different
incidence angles
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13. SOLAR
Reflector Shields to Increase Aperture Area
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14. SOLAR
Shield Reflector benefits
h/L 0,3 h/L 0,8 h/L 1 h/L 0,3 h/L 0,8 h/L 1 h/L 0,3 h/L 0,8 h/L 1
3,0 3,0 3,0
3,0 3,0 3,0
2,0 2,0 2,0
Seasonal
relative gain in %
n %
n %
1,0 1,0 1,0
relative gain in
relative gain in
0,0 0,0 0,0
influence at
fl
‐1,0
Almeria shown
‐1,0 ‐1,0
December 21st March / Sep. 21st June 21st by reference days
‐2,0 ‐2,0 ‐2,0
-3,0
‐3,0 -3,0
‐3,0 -3,0
‐3,0
4 6 8 10 12 14 16 18 20 22 4 6 8 10 12 14 16 18 20 22 4 6 8 10 12 14 16 18 20 22
4 22 4 22 4 22
time in h time in h time in h
Annual yield calculation of
shield performance
considering incident angles
depending on latitudes
without local DNI effects.
(reflectance: 80%)
(reflectance: 80%)
Slide 14 of 5 Slides
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15. SOLAR
PTR 70 New Design
SCHOTT PTR®70 Receiver –
Improved performance
Absorber
Ab b coating stable up t
ti t bl to
operating temperatures of 450°C
Absorptance ≥ 95,5%
Emittance
E i ≤ 9 5% @400°C
9,5%
Transmittance ≥ 96,5%
Thermal losses < 250 W/m (400°C)
Aperture length: > 96,7% @ working temperature (300 - 400°C)
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16. SOLAR
Gracias por su atención!!
© Copyright 2011 SCHOTT Solar CSP GmbH, All Rights Reserved