Interoffice Memorandum
System Planning
MEMO:
DATE:
TO:
FROM:
SUBJECT:
SP-2013-07
February 15, 2012
Scott Waples
Richard Maguire
IRP Generation Study - Benewah to Boulder 230kV (BB-IRP)
Introduction
This study addresses a request from Avista’s Power Supply Department for the 2013 IRP regarding
new generation on the Benewah - Boulder 230 kV Transmission Line at one of two capacity levels:
150 MW
300 MW
The study presents information and discussion on the follow topics:
Power flow impact to the transmission system
Transmission system upgrades necessary to deliver requested generation
Study Assumptions and Methodology
The five year planning horizon Avista planning cases, as documented in SP-2011-03 – 2011 Planning
Cases Summary Data, are modified with the following projects and adjustments prior to system
analysis:
LGIR #35 project (200 MW at Thornton 230 kV Substation)
LGIR #36 project (105 MW at Thornton 230 kV Substation)
BB-IRP topology:
o Benewah – Boulder 230kV Transmission Line tapped 13.1 electrical miles North
of Benewah 230 kV Substation
o Generic generator installed on new BB-IRP 230 kV bus
The following cases are used during this study:
Avista Heavy Summer High Hydro (“HSHH”) case: AVA-11hs2a-12BA2085
o Table 1 shows power flows for this case
Avista Heavy Summer Low Hydro (“HSLH”) case: AVA-11hs2a-12BA2085-LH
o Table 2 shows power flows for this case
Avista Light Summer with High West of Hatwai (High Transfers or “HT”)Flows: AVA11ls1ae-12BA1251-WOH4277
o Table 3 shows power flows for this case with BB-IRP output = 300 MW
Benewah – Boulder 2013 IRP Study
Table 1: Regional Power Flows for Heavy Summer Case
Western Montana Hydro
Noxon Rapids (562MW)
Cabinet Gorge (265MW)
Libby (605MW)
Hungry Horse (430MW)
1098.1 MW
399.4 MW
184.7 MW
324.0 MW
190.0 MW
West of Hatwai (Path 6)
Lolo-Oxbow 230kV
Dry Creek-Walla Walla 230kV
951.8 MW
296.0 MW
184.1 MW
West of Cabinet
Montana-Northwest (Path 8)
1581.7 MW
979.0 MW
Colstrip Total
Colstrip 1 (330MW)
Colstrip 2 (330MW)
Colstrip 3 (823MW)
Colstrip 4 (823MW)
330.0 MW
330.0 MW
795.5 MW
804.9 MW
Idaho-Northwest (Path 14)
-585.4 MW
Midpoint-Summer Lake (Path 75) -48.9 MW
Idaho-Montana (Path 18)
-296.3 MW
Rathdrum Thermal (175MW)
Lancaster Thermal (270MW)
Spokane River Hydro
Boundary Hydro (1040MW)
0.0 MW
249.0 MW
88.3 MW
635.0 MW
Lower Snake/N.F. Clearwater
Dworshak (458MW)
Lower Granite (930MW)
Little Goose (930MW)
Lower Monumental (930MW)
Coulee Generation
Coulee 500 kV
Coulee 230 kV
316.0 MW
554.2 MW
555.5 MW
531.5 MW
2308.5 MW
1292.7 MW
South of Boundary
North of John Day (Path 73)
TOT 4A (Path 37)
Miles City DC
582.9 MW
7034.7 MW
407.0 MW
142.0 MW
Path C (Path 20)
Borah West (Path 17)
Bridger West (Path 19)
Pacific AC Intertie (Path 66)
Pacific DC Intertie (Path 65)
118.7 MW
837.4 MW
2191.6 MW
4430.9 MW
2980.0 MW
Northwest Load
Idaho Load
Montana Load
Avista Native Load
Avista Balancing Area Load
Clearwater Load
25129.6 MW
3702.5 MW
1836.8 MW
-1594.3 MW
1885.6 MW
58.3 MW
Table 2: Regional Power Flows for Light Summer Case
Western Montana Hydro
Noxon Rapids (562MW)
Cabinet Gorge (265MW)
Libby (605MW)
Hungry Horse (430MW)
627.1 MW
138.8 MW
82.3 MW
216.0 MW
190.0 MW
West of Hatwai (Path 6)
Lolo-Oxbow 230kV
Dry Creek-Walla Walla 230kV
120.3 MW
277.0 MW
159.6 MW
West of Cabinet
Montana-Northwest (Path 8)
1110.7 MW
970.1 MW
Colstrip Total
Colstrip 1 (330MW)
Colstrip 2 (330MW)
Colstrip 3 (823MW)
Colstrip 4 (823MW)
330.0 MW
330.0 MW
764.2 MW
776.0 MW
Idaho-Northwest (Path 14)
-585.9 MW
Midpoint-Summer Lake (Path 75) -76.0 MW
Idaho-Montana (Path 18)
-274.8 MW
Rathdrum Thermal (175MW)
Lancaster Thermal (270MW)
Spokane River Hydro
Boundary Hydro (1040MW)
0.0 MW
249.0 MW
58.1 MW
310.0 MW
Lower Snake/N.F. Clearwater
Dworshak (458MW)
Lower Granite (930MW)
Little Goose (930MW)
Lower Monumental (930MW)
Coulee Generation
Coulee 500 kV
Coulee 230 kV
316.0 MW
554.2 MW
555.5 MW
531.5 MW
3066.4 MW
1292.7 MW
South of Boundary
North of John Day (Path 73)
TOT 4A (Path 37)
Miles City DC
299.4 MW
6931.9 MW
399.6 MW
142.0 MW
Path C (Path 20)
Borah West (Path 17)
Bridger West (Path 19)
Pacific AC Intertie (Path 66)
Pacific DC Intertie (Path 65)
133.4 MW
830.6 MW
2188.8 MW
4222.6 MW
2980.0 MW
Northwest Load
Idaho Load
Montana Load
Avista Native Load
Avista Balancing Area Load
Clearwater Load
25129.6 MW
3702.5 MW
1836.8 MW
-1594.3 MW
1874.1 MW
75.8 MW
Benewah – Boulder 2013 IRP Study
Table 3: Regional Power Flows for High Transfer Case
Western Montana Hydro
Noxon Rapids (562MW)
Cabinet Gorge (265MW)
Libby (605MW)
Hungry Horse (430MW)
1548.0 MW
432.2 MW
195.8 MW
540.0 MW
380.0 MW
West of Hatwai (Path 6)
Lolo-Oxbow 230kV
Dry Creek-Walla Walla 230kV
4251.2 MW
140.1 MW
189.5 MW
West of Cabinet
Montana-Northwest (Path 8)
3204.5 MW
2040.8 MW
Colstrip Total
Colstrip 1 (330MW)
Colstrip 2 (330MW)
Colstrip 3 (823MW)
Colstrip 4 (823MW)
330.0 MW
330.0 MW
777.6 MW
782.9 MW
Idaho-Northwest (Path 14)
741.0 MW
Midpoint-Summer Lake (Path 75) 831.7 MW
Idaho-Montana (Path 18)
-198.3 MW
Rathdrum Thermal (175MW)
Lancaster Thermal (270MW)
Spokane River Hydro
Boundary Hydro (1040MW)
116.4 MW
118.1 MW
152.4 MW
975.0 MW
Lower Snake/N.F. Clearwater
Dworshak (458MW)
Lower Granite (930MW)
Little Goose (930MW)
Lower Monumental (930MW)
Coulee Generation
Coulee 500 kV
Coulee 230 kV
168.2 MW
0.0 MW
141.8 MW
310.0 MW
825.7 MW
125.0 MW
South of Boundary
North of John Day (Path 73)
TOT 4A (Path 37)
Miles City DC
961.8 MW
4775.0 MW
448.4 MW
200.0 MW
Path C (Path 20)
Borah West (Path 17)
Bridger West (Path 19)
Pacific AC Intertie (Path 66)
Pacific DC Intertie (Path 65)
528.7 MW
1570.2 MW
2098.0 MW
3136.7 MW
1999.9 MW
Northwest Load
Idaho Load
Montana Load
Avista Native Load
Avista Balancing Area Load
Clearwater Load
17796.4 MW
2326.0 MW
1339.5 MW
-837.0 MW
680.3 MW
71.1 MW
Benewah – Boulder 2013 IRP Study
Study Results
Thermal Performance during Category A conditions
1
This preliminary study indicates the Avista Transmission System has adequate capacity to integrate 300
MW at the proposed interconnection point during Category A all lines in service conditions.
Thermal Performance during Category B and Category C conditions
Table 4 shows preliminary results of a study using PowerWorld Simulator’s Available Transfer Capability
(ATC) tool for generation injections at BB-IRP. This tool generates a list of facility thermal violations (From
To) that arise under contingency conditions for incremental increases in generation output (BB WM).
When the results for each case under study are collected and analyzed together with results from
standard contingency analysis studies, this tool provides an idea of what facilities overload for rising
levels of generation output.
As the table shows, there are six facilities that come into violation for a requested BB-IRP output of 150
MW, and there are an additional five facilities that come into violation for a requested BB-IRP output of
300 MW.
Table 4: Incremental generation analysis for BB-IRP IRP request
2
Case
MW Output Limiting Contingency
From Name
To Name
HSLH
27.11
BF: A470 Westside 115 kV, College & Walnut-Westside
GLENTAP
NINTHCNT
HSHH
28.2
BUS: Westside 115 kV
POSTSTRT
THIRHACH
HT
84.08
N-1: Hatwai - Moscow 230 230 kV
MOSCOW
MOSCOWX
HSLH
106.34
BUS: Westside 115 kV
ROSSPARK
THIRHACH
HSHH
106.63
BF: A413 Westside 115 kV, Ninemile-Westside
POSTSTRT
THIRHACH
HSHH
112.15
BF: A689 Ninth & Central South 115 kV, Ninth & Central-Otis Orchards
POSTSTRT
THIRHACH
HSLH
116.64
N-2: Bell - Westside 230 kV & Coulee - Westside 230 kV
GLENTAP
NINTHCNT
HSLH
117.24
BUS: Westside 230 kV
GLENTAP
NINTHCNT
HSLH
123.43
BF: A370 Bell S1 & S2 230 kV
BEACON N
BEACON N
HSHH
160.37
N-1: Shawnee - Thornton 230 kV
MOSCOW
MOSCOWX
HSHH
164.3
N-1: North Lewiston - Shawnee 230 kV
TERRVIEW
NPULLMAN
HSHH
173.34
BUS: North Lewiston 230 kV
TERRVIEW
NPULLMAN
HSLH
184.24
BF: A413 Westside 115 kV, Ninemile-Westside
ROSSPARK
THIRHACH
HT
206.31
N-2: Beacon - Boulder 230 kV & Beacon - Rathdrum 230 kV
BOULDERE
IRVIN
HT
215.35
BF: R427 Beacon North & South 230 kV
BOULDERE
IRVIN
HT
215.68
N-2: Beacon - Boulder 230 kV & Beacon - Rathdrum 230 kV
IRVIN
MILLWOOD
HT
223.63
BF: R427 Beacon North & South 230 kV
IRVIN
MILLWOOD
HSHH
253.83
N-2: Shawnee - Thornton 230 kV & Lind - Shawnee 115 kV
MOSCOW
MOSCOWX
HT
269.19
N-2: Beacon - Boulder 230 kV & Beacon - Rathdrum 230 kV
BOULDERW
SPKINDPK
HT
271.24
BUS: Hatwai 230 kV
MOSCOWX
MOSCOW
HSLH
272.76
BUS: Hatwai 230 kV
MOSCOWX
MOSCOW
HSLH
275.44
PSF: Ninth & Central South 115 kV
BEACON S
NINTHCNT
HSHH
275.67
BUS: Westside 230 kV
POSTSTRT
THIRHACH
HSHH
275.84
N-2: Bell - Westside 230 kV & Coulee - Westside 230 kV
POSTSTRT
THIRHACH
HT
280.08
BF: R427 Beacon North & South 230 kV
BOULDERW
SPKINDPK
HSLH
298.33
BUS: North Lewiston 230 kV
HATWAI
LOLO
HT
300.27
N-2: Bell - Taft 500 kV and Bell - Lancaster 230 kV
BOULDER
BB-IRP
1
Contingency category descriptions can be found at: http://www.nerc.com/files/TPL-001-0.pdf
2
BF = Breaker Failure; PSF = Protection System Failure; N-X contingencies refer to ‘X’ transmission element outages
Benewah – Boulder 2013 IRP Study
Notes regarding thermal performance:
Avista has planned projects that mitigate some of the above mentioned facility violations.
However, some of the planned projects also result in new facility thermal violations during
contingencies. Further study of planned projects and potential options will be necessary.
Preliminary studies indicate some reduction in the above thermal violations when Projects #35
and #36 are removed from study, but the reduction in thermal violations is confined mainly to
limiting facilities south of BB-IRP. Without Projects #35 and #36, significant power continues to
flow north through the Boulder 230 kV substation and onto the local 115 kV Transmission
System in the Spokane and Spokane Valley areas.
Voltage Performance
Preliminary studies show voltage issues of a nature that can be addressed with properly sited reactive
support. Further detailed studies can be used to determine the exact amount and location of any reactive
support necessary to mitigate facility voltage violations.
Benewah – Boulder 2013 IRP Study
Potential Solutions Options3
230 kV Switching station required for all options mentioned below:
4 position double bus double breaker ~ $4 M
Option 1: Reconductor facilities brought into violation due to the requested generation
150 MW option would require:
o $3.41 M of 115 kV upgrades
300 MW option would require an additional:
o $1.9 M of 115 kV upgrades
o $5.36 M of 230 kV upgrades
Option 2: Complete currently planned projects and reconductor limiting facilities
Currently Planned Projects:
o Lancaster Interconnection
o Spokane Valley Transmission Reinforcement
o Moscow Transformer Replacement
o Westside Transformer Replacement
150 MW option would require:
o $2.4 M of 115 kV upgrades
300 MW option would require an additional:
o $932 K of 115 kV upgrades
o $5.36 M of 230 kV upgrades
Conclusion
This project is a feasible project based on the preliminary analysis performed. A summary of options and
cost estimates is given in Table 3.
Option
1
1
2
3
3
Maximum Output
150 MW
300 MW
150 MW
300 MW
Total Cost ($000)
$7,410
$14,670
$6,400
$12,690
All construction costs are in 2013-year dollars and based on engineering judgment alone with +/- 50% accuracy