Solar Trough Generation The California Experience
Presented at ASES FORUM 2001,
Washington DC
Robert Cable
KJC OPERATING
COMPANY
41100 Hwy 395
Boron, CA 93516
OVERVIEW
• SEGS Background & Description
• Historic Performance Trends
• The Recent California Experience
• Summary / Concluding Remarks
SEGS
Solar Electric Generating Systems
LS-1
Aperture
2.5m
LS-2
5m
LS-3
LS-4
Prototype
5.76m
10.5m
SCA
Length
50.4m
48m
99m
49m
Distance
Between
Pylons
6.3m
12m*
15m
tbd
547m2
504m2
Reflecting
Surface
Fluid
Temperature
2
128m
307°C
235m2
350°C
390°C
tbd
Nine Hybrid Solar Power Plants
Currently Operating
SEGS
SEGS
SEGS
SEGS
SEGS
SEGS
SEGS
SEGS
SEGS
I
II
III
IV
V
VI
VII
VIII
IX
14
30
30
30
30
30
30
80
80
MWe
MWe
MWe
MWe
MWe
MWe
MWe
MWe
MWe
since
since
since
since
since
since
since
since
since
1984
1985
1986
1986
1987
1988
1988
1989
1990
*At SEGS VI & VII, the distance was increased to 15m.
Total Capacity: 354 MWe
Kramer Junction SEGS
• Five 30 MW Hybrid Power Plants
•• SEGS
SEGS III-V:
III-V: Dual
Dual Inlet
Inlet Rankine
Rankine Steam
Steam Cycle
Cycle
•• SEGS
SEGS VI-VII:
VI-VII: Single
Single Inlet
Inlet Reheat
Reheat Rankine
Rankine Steam
Steam Cycle
Cycle
• Annual Energy Input Entering Steam Turbine
•• 75%
75% Solar
Solar Energy
Energy
•• 25%
25% Natural
Natural Gas
Gas Boilers
Boilers
• Typical 30 MW SEGS (VI) Characteristics
•• 800
800 LS2
LS2 SCAs
SCAs
•• 188,000
188,000 m2
m2 of
of Reflective
Reflective Aperture
Aperture Area
Area
•• 96,000
96,000 Reflector
Reflector Panels
Panels
•• 9,000
9,000 HCE
HCE Tubes
Tubes
Gross Solar Production
SEGS III-VII
450000
400000
SOLAR PRODUCTION - MWh
350000
300000
250000
200000
150000
100000
50000
0
1989
1990
1991
1992
GROS S S OLAR
1993
1994
HCE LOS SES
1995
RP LOS SES
1996
1997
REFLECT LOSS ES
1998
1999
2000
Kramer Junction SEGS Collector Availability
100.0
99.5
99.0
Availability - %
98.5
98.0
97.5
97.0
96.5
96.0
95.5
95.0
1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000
Kramer Junction SEGS Peak Capacity
112
On-Peak Capacity - %
110
108
106
104
102
100
98
1989
1990
1991
1992
1993
1994
Site Average
1995
1996
1997
1998
1999
2000
The California Experience
• Gas Prices Increased!
• El Paso gas awarded capacity away
from California
• Pipeline explosion in New Mexico
• Repairs and inspections to many
other pipelines
• Storage reserves low due to high usage in
summer
December 01
• SRAC posting was based on $14 gas
• SCE petitioned to contest posted SRAC to
CPUC
•SCE has fixed pricing to consumer
• QF’s (12,000 MW) offline
•Planned Outages - Heavy summer ops
•Forced Outages - Big losses?
•Air Permits running out or gone
•Uncertainty
• STAGE 3 EMERGENCIES DAILY!!!!!
December 01 (Cont)
• KJ SEGS ran solar only mostly
• Used gas up to 25% FERC
• Used extra gas in November
• FERC lifted 25% limitation
• KJ SEGS could not operate at loss
• KJ made attempts with SCE to produce
with revenue based on gas prices
• SCE petitioning CPUC to do away with
25% to 0% earlier in year
January
• SRAC posted - SCE protest
•KJ ran with gas until 1/12
•No November payment (QF’s)!!!!!
•Planned Outages
•Forced Outages
•No Payment no Power
• KJ SEGS ran solar only
•Came out of 2 planned outages early
•Postponed 2 planned outages
February - March
• Legislature, QF’s, Utilities in Sacramento
• CPUC ordered CDWR to buy (loan) power to SCE
• SCE continues to receive monies from
consumers
• SCE must pay back “loan” but could limit cost
recovery and financial stability
• Concerned about ability to pay QF’s
• CPUC adopted rate increase - 4.8 billion/yr
February - March (cont)
• CDWR entered into MOU for sale of transmission system 2.8 billion
• SCE debt on 1/31/01 - 3.5 billion
• SRAC Formula Basically Unchanged
• Gas Increase?
• KJC OC Paid For April 01 on April 17
• New Billing Structure
• No Word on $11 Million Back Payments
Summary & Conclusion
The SEGS Plants are Reliable
Over 100 years of Operational Experience
SEGS Plants Have Ability to Stabilize Production
Emergencies.
The California Experience - Why Didn’t it Get Fixed?
February - March (cont)
• Legislature, QF’s, Utilities in Sacramento
• CPUC ordered CDWR to buy (loan) power to SCE
• SCE continues to receive monies from
consumers
• SCE must pay back “loan” but could limit cost
recovery and financial stability
• Concerned about ability to pay QF’s
• CPUC adopted rate increase - 4.8 billion/yr
30
30 MW
MW SEGS
SEGS Configuration
Configuration at
at Kramer
Kramer Junction,
Junction, California,
California, USA
USA
Engineering Model - %
SOLAR PRODUCTION LOSSES
% of Engineering Model, SEGS III-VII
25.0%
20.0%
15.0%
10.0%
5.0%
0.0%
1995
HCE
RP's
1996
1997
Avail
Reflect
1998
Frcd Out
1999
2000
Plnd Out
SEGS VI
Annual Solar Efficiency
60
50
Efficiency - %
40
30
20
10
0
Jan
Feb
Mar
Apr
May
Solar Thermal Efficiency
Jun
Jul
Aug
Sep
Oct
Solar to Electric Efficiency
Nov
Dec
SEGS VI
Solar Efficiencies - Peak Day
70%
1200
60%
50%
Efficiency
800
40%
600
30%
400
20%
200
10%
0%
05:00
0
07:00
09:00
11:00
Solar Field Efficiency
13:00
15:00
17:00
Solar to Electric Efficiency
19:00
21:00
DNI
Direct Radiation (W/M2)
1000
Kramer Junction SEGS Efficiency
15.0
Solar Production Efficiency - %
14.0
13.0
12.0
11.0
10.0
9.0
8.0
1995
1996
III
1997
IV
1998
V
1999
VI
VII
2000
SCE Time of Use (TOU) Rate Periods
SEGS III-VII
Simple
Simple Schematic
Schematic of
of Parabolic
Parabolic Trough
Trough Operation
Operation
(North-South
(North-South Axis)
Axis)
Modes
Modes of
of Operation
Operation
Total O&M Costs
8
1000
7
5
500
4
3
250
2
1
0
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
Net Production - MWh
O&M Costs - Cents/KWh
750
6
LS-2 RP AVAILABILITY
Actual & Projected
1
Availability
0.98
0.96
0.94
0.92
0.9
1995
1996
III
1997
IV
V
1998
VI
1999
VII
HCE AVAILABILITY
Actual
100%
98%
96%
Availability
94%
92%
90%
88%
86%
84%
82%
80%
1995
1996
1997
III
IV
1998
V
VI
1999
VII
2000
Kramer Junction SEGS LS-2 RP Breakage
3000
2500
2000
1500
1000
500
0
1995
1996
1997
III
IV
1998
V
VI
1999
VII
2000
Kramer Junction SEGS HCE Glass Breakage
900
800
700
600
500
400
300
200
100
0
1995
1996
1997
III
IV
1998
V
VI
1999
VII
2000
Kramer Junction SEGS Reflectivity
SITE REFLECTIVITY
Actual & Targeted, SEGS III-VII
94
Reflectivity Percentage
92
90
88
86
1995
1996
Jan, Feb, Dec
(Winter Months)
1997
1998
Mar, Apr, Sep, Oct, Nov
(Equinox Months)
1999
2000
May, Jun, Jul, Aug
(Summe r Months)