Bruce A. Measure Chair Montana Rhonda Whiting Montana W. Bill Booth Idaho James A. Yost Idaho Dick Wallace Vice-Chair Washington Tom Karier Washington Melinda S. Eden Oregon Joan M. Dukes Oregon September 8, 2010 MEMORANDUM TO: FROM: SUBJECT: Power Committee Wally Gibson Transmission Congestion and Resource Adequacy Analysis Several of the Council s models, including that used for resource adequacy analysis, contain only limited representations of the Northwest transmission system and its constraints. This raises a question whether that limited representation distorts the results of the adequacy analysis by assuming transmission access to certain resources when that access may actually be limited by contractual limitations or physical transmission congestion. The staff will present the results of an inquiry into that question. The staff has previously presented a review of major transmission additions that are in various planning stages, noting that the driver for some of the upgrade capability is new generation to serve regional and extra-regional sales and RPS requirements. The present analysis focuses on load service requirements within the Northwest. Two kinds of congestion were investigated: lack of Available Transmission Capacity (ATC) and physical power flows near or at Operating Transfer Capability (OTC) limits. The former is a measure of transmission capacity available for sale; the latter is a real time reliability limit. Six major paths or flowgates in the Northwest were examined, looking at both winter and summer conditions for the power flow issue. The general conclusion of the analysis is that there are two areas where the current transmission system can become a constraint on load service in the intermediate term, the Portland area and Idaho. In both of these areas, transmission expansion projects and/or new local generation projects to alleviate potential problems are in the planning and development stages with target dates to prevent load service problems in the future. The staff will continue to investigate expanding the capabilities of the Council s models to incorporate more transmission information as warranted. 851 S.W. Sixth Avenue, Suite 1100 Steve Crow 503-222-5161 Portland, Oregon 97204-1348 Executive Director 800-452-5161 www.nwcouncil.org Fax: 503-820-2370
Northwest Transmission Constraints and Resource Adequacy Impacts Wally Gibson Wally Gibson Northwest Power and Conservation Council Bend, Oregon September 21, 2010
Overview Issue: To what extent are transmission constraints likely to impede access to resources to meet peak loads and to create near-term adequacy problems? Look at subregions of NW rather than region as a whole Approach: Review ATC availability Review historical path flows, pre-recession data Cold winter December 2008 and hot summer July 2006 Summary: Some problems, especially Idaho and Portland area Not generally an immediate problem Likely to be a mid-term problem, being addressed in planning efforts, both transmission and new local generation Sep 21, 2010 2
Transmission Congestion Shows up in two ways No Available Transmission Capacity (ATC) ATC shows what capacity is available for sale Power flows on paths near Operating Transfer Capability (OTC), a real time reliability limit OTC often less than full rating, depending on conditions Paths/flowgates/cutplanes: Limiting and monitored sets of lines, between balancing areas or internal to a balancing area Not all congestion relevant to NW load service and adequacy analysis, e.g., summer access to interties N>S not an adequacy problem Sep 21, 2010 3
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Available Transmission Capacity Sold in time increments: long-term (>= year), shorter terms down to hourly Measured by looking at ability of transmission system to reliably carry more load Generally, BPA looks at impacts of service between source and sink on all flowgates affected by power flow Power flows across all lines in the system, not just the most direct link Next slide illustrates power flow from Mid-C to Portland, arrow width ~ proportional to power flow Implication: most-constrained flowgate on the system can limit ATC on other flowgates Sep 21, 2010 5
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South of Allston Primarily constraining on summer power flows towards Portland area and towards the intertie I-5 and Canadian generation loads the path Upper Columbia (vs. lower Columbia) generation loads the path No long-term ATC available Constraining on ATC availability on other flowgates, including east to west History of past congestion problems for Bonneville New I-5 corridor gas generation 2007-08 : 1318 MW (1049 MW PGE and IPP, 319 MW PSE) Relief projects: BPA I-5 Corridor project, PGE South of Allston 230 kv line (in proposal stage) Sep 21, 2010 8
South of Allston Cold Dec 2008 SOUTH OF ALLSTON FLOWGATE Actual Loadings and OTCs: 01Dec08-31Dec08 (31 Days) N-to-S MEAN 15-MINUTE LOAD: S-OF-ALLSTON FLOWGATE (65757) MEAN 15-MINUTE OTC: S-OF-ALLSTON FLOWGATE (93234) 3600 3300 3000 2700 2400 2100 1800 1500 MW 1200 900 600 300 0-300 -600-900 S-to-N 1Dec 2Dec 3Dec 4Dec 5Dec 6Dec 7Dec 8Dec 9Dec 10Dec 11Dec 12Dec 13Dec 14Dec 15Dec 16Dec 17Dec 18Dec 19Dec 20Dec 21Dec 22Dec 23Dec 24Dec 25Dec 26Dec 27Dec 28Dec 29Dec 30Dec 31Dec Date Source: 15-minute average of 2-second SCADA readings via PI Sep 21, 2010 9
South of Allston Hot Jul 2006 ALLSTON-KEELER FLOWGATE Actual Loadings and OTCs: 01JUL06-31JUL06 MEAN 15-MINUTE LOAD: ALLSTON-KEELER FLOWGATE (963) N-to-S MEAN 15-MINUTE OTC: ALLSTON-KEELER FLOWGATE (47673) 3200 3000 2800 2600 2400 2200 2000 1800 1600 MW 1400 1200 1000 800 600 400 200 0-200 -400-600 S-to-N 1Jul 2Jul 3Jul 4Jul 5Jul 6Jul 7Jul 8Jul 9Jul 10Jul 11Jul 12Jul 13Jul 14Jul 15Jul 16Jul 17Jul 18Jul 19Jul 20Jul 21Jul 22Jul 23Jul 24Jul 25Jul 26Jul 27Jul 28Jul 29Jul 30Jul 31Jul Date Source: 15-minute average of 5-minute instantaneous readings via SCADA Sep 21, 2010 10
South of Allston Jul 2007 SOUTH OF ALLSTON FLOWGATE Actual Loadings and OTCs: 01Jul07-31Jul07 (31 Days) N-to-S MEAN 15-MINUTE LOAD: S-OF-ALLSTON FLOWGATE (65757) MEAN 15-MINUTE OTC: S-OF-ALLSTON FLOWGATE (93234) 3400 3200 3000 2800 2600 2400 2200 2000 MW 1800 1600 1400 1200 1000 800 600 400 200 0 S-to-N 1Jul 2Jul 3Jul 4Jul 5Jul 6Jul 7Jul 8Jul 9Jul 10Jul 11Jul 12Jul 13Jul 14Jul 15Jul 16Jul 17Jul 18Jul 19Jul 20Jul 21Jul 22Jul 23Jul 24Jul 25Jul 26Jul 27Jul 28Jul 29Jul 30Jul 31Jul Date Source: 15-minute average of 2-second SCADA readings via PI Sep 21, 2010 11
South of Allston Hot Aug 2010 SOUTH OF ALLSTON FLOWGATE Actual Loadings and OTCs: 01Aug10-31Aug10 (31 Days) N-to-S MEAN 15-MINUTE LOAD: S-OF-ALLSTON FLOWGATE (65757) MEAN 15-MINUTE OTC: S-OF-ALLSTON FLOWGATE (93234) 4200 3900 3600 3300 3000 2700 2400 2100 MW 1800 1500 1200 900 600 300 0-300 S-to-N 1Aug 2Aug 3Aug 4Aug 5Aug 6Aug 7Aug 8Aug 9Aug 10Aug 11Aug 12Aug 13Aug 14Aug 15Aug 16Aug 17Aug 18Aug 19Aug 20Aug 21Aug 22Aug 23Aug 24Aug 25Aug 26Aug 27Aug 28Aug 29Aug 30Aug 31Aug Date Source: 15-minute average of 2-second SCADA readings via PI Sep 21, 2010 12
South of Allston Cool with Low BC Summer Exports Jun 2010 SOUTH OF ALLSTON FLOWGATE Actual Loadings and OTCs: 01Jun10-30Jun10 (30 Days) N-to-S MEAN 15-MINUTE LOAD: S-OF-ALLSTON FLOWGATE (65757) MEAN 15-MINUTE OTC: S-OF-ALLSTON FLOWGATE (93234) 3400 3200 3000 2800 2600 2400 2200 2000 1800 1600 MW 1400 1200 1000 800 600 400 200 0-200 -400-600 S-to-N 1Jun 2Jun 3Jun 4Jun 5Jun 6Jun 7Jun 8Jun 9Jun 10Jun 11Jun 12Jun 13Jun 14Jun 15Jun 16Jun 17Jun 18Jun 19Jun 20Jun 21Jun 22Jun 23Jun 24Jun 25Jun 26Jun 27Jun 28Jun 29Jun 30Jun Date Source: 15-minute average of 2-second SCADA readings via PI Sep 21, 2010 13
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Cross-Cascades North and South Parallel paths, deliver east side generation to west side loads Most stressed during heavy winter loads, especially if west side generation operating at low levelsl Studied by ColumbiaGrid (2010 Update to 2009 Biennial Plan) Potential need for new transmission in 10-year time frame Interim upgrades to capability can be made Long-term firm ATC available North (rated 10,200 MW) 2010 958 MW,, 2019 531 MW South (rated 7000 MW) 2010 1102 MW,, 2019 674 MW Sep 21, 2010 15
Cross-Cascades North Cold Dec 2008 WEST OF CASCADES NORTH FLOWGATE Actual Loadings and OTCs: 01Dec08-31Dec08 (31 Days) E-to-W 11000 MEAN 15-MINUTE LOAD: WEST OF CASCADES NORTH FLOWGATE (43515) MEAN 15-MINUTE OTC: WEST OF CASCADES NORTH FLOWGATE (61465) 10000 9000 8000 7000 6000 MW 5000 4000 3000 2000 1000 0 W-to-E 1Dec 2Dec 3Dec 4Dec 5Dec 6Dec 7Dec 8Dec 9Dec 10Dec 11Dec 12Dec 13Dec 14Dec 15Dec 16Dec 17Dec 18Dec 19Dec 20Dec 21Dec 22Dec 23Dec 24Dec 25Dec 26Dec 27Dec 28Dec 29Dec 30Dec 31Dec Date Source: 15-minute average of 2-second SCADA readings via PI Sep 21, 2010 16
Cross-Cascades North Hot Jul 2006 E-to-W 14000 13000 12000 11000 WEST OF CASCADES NORTH FLOWGATE Actual Loadings and OTCs: 01Jul06-31Jul06 (31 Days) MEAN 15-MINUTE LOAD: WEST OF CASCADES NORTH FLOWGATE (43515) MEAN 15-MINUTE OTC: WEST OF CASCADES NORTH FLOWGATE (61465) 10000 9000 8000 MW 7000 6000 5000 4000 3000 2000 1000 0 W-to-E 1Jul 2Jul 3Jul 4Jul 5Jul 6Jul 7Jul 8Jul 9Jul 10Jul 11Jul 12Jul 13Jul 14Jul 15Jul 16Jul 17Jul 18Jul 19Jul 20Jul 21Jul 22Jul 23Jul 24Jul 25Jul 26Jul 27Jul 28Jul 29Jul 30Jul 31Jul Date Source: 15-minute average of 2-second SCADA readings via PI Sep 21, 2010 17
Cross-Cascades North Outage May 2010 WEST OF CASCADES NORTH FLOWGATE Actual Loadings and OTCs: 01May10-31May10 (31 Days) E-to-W 11000 MEAN 15-MINUTE LOAD: WEST OF CASCADES NORTH FLOWGATE (43515) MEAN 15-MINUTE OTC: WEST OF CASCADES NORTH FLOWGATE (61465) 10000 9000 8000 7000 MW 6000 5000 4000 3000 2000 1000 0 W-to-E 1May 2May 3May 4May 5May 6May 7May 8May 9May 10May 11May 12May 13May 14May 15May 16May 17May 18May 19May 20May 21May 22May 23May 24May 25May 26May 27May 28May 29May 30May 31May Date Source: 15-minute average of 2-second SCADA readings via PI Sep 21, 2010 18
Cross-Cascades South Cold Dec 2008 WEST OF CASCADES S SOUTH FLOWGATE Actual Loadings and OTCs: 01Dec08-31Dec08 (31 Days) E-to-W MEAN 15-MINUTE LOAD: WEST OF CASCADES SOUTH FLOWGATE (43319) MEAN 15-MINUTE OTC: WEST OF CASCADES SOUTH FLOWGATE (61466) 7500 7000 6500 6000 5500 5000 4500 MW 4000 3500 3000 2500 2000 1500 1000 500 0 W-to-E 1Dec 2Dec 3Dec 4Dec 5Dec 6Dec 7Dec 8Dec 9Dec 10Dec 11Dec 12Dec 13Dec 14Dec 15Dec 16Dec 17Dec 18Dec 19Dec 20Dec 21Dec 22Dec 23Dec 24Dec 25Dec 26Dec 27Dec 28Dec 29Dec 30Dec 31Dec Date Source: 15-minute average of 2-second SCADA readings via PI Sep 21, 2010 19
Cross-Cascades South Hot Jul 2006 E-to-W WEST OF CASCADES SOUTH FLOWGATE Actual Loadings and OTCs: 01Jul06-31Jul06 (31 Days) MEAN 15-MINUTE LOAD: WEST OF CASCADES SOUTH FLOWGATE (43319) MEAN 15-MINUTE OTC: WEST OF CASCADES SOUTH FLOWGATE (61466) 8500 8000 7500 7000 6500 6000 5500 5000 MW 4500 4000 3500 3000 2500 2000 1500 1000 500 0 W-to-E 1Jul 2Jul 3Jul 4Jul 5Jul 6Jul 7Jul 8Jul 9Jul 10Jul 11Jul 12Jul 13Jul 14Jul 15Jul 16Jul 17Jul 18Jul 19Jul 20Jul 21Jul 22Jul 23Jul 24Jul 25Jul 26Jul 27Jul 28Jul 29Jul 30Jul 31Jul Date Source: 15-minute average of 2-second SCADA readings via PI Sep 21, 2010 20
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North of John Day Primarily constraining on summer power flows towards the intertie Especially if Lower Columbia generation reduced for spill and Upper Columbia generation replaces it Not constraining on winter or summer load service in the NW Long-term ATC available, but no long-term ATC available on interties,,perhaps p limiting demand Sep 21, 2010 22
North of John Day Cold Dec 2008 NORTH OF JOHN DAY FLOWGATE Actual Loadings and OTCs: 01DEC08-31DEC08 N-to-S MEAN 15-MINUTE LOAD: NORTH OF JOHN DAY FLOWGATE (40348) MEAN 15-MINUTE OTC: NORTH OF JOHN DAY FLOWGATE (42267) 9000 8000 7000 6000 5000 4000 MW 3000 2000 1000 0-1000 -2000-3000 S-to-N 1Dec 2Dec 3Dec 4Dec 5Dec 6Dec 7Dec 8Dec 9Dec 10Dec 11Dec 12Dec 13Dec 14Dec 15Dec 16Dec 17Dec 18Dec 19Dec 20Dec 21Dec 22Dec 23Dec 24Dec 25Dec 26Dec 27Dec 28Dec 29Dec 30Dec 31Dec Date Source: 15-minute average of 5-minute instantaneous readings via SCADA Sep 21, 2010 23
North of John Day Hot Jul 2006 NORTH OF JOHN DAY FLOWGATE Actual Loadings and OTCs: 01JUL06-31JUL06 MEAN 15-MINUTE LOAD: NORTH OF JOHN DAY FLOWGATE (40348) N-to-S MEAN 15-MINUTE OTC: NORTH OF JOHN DAY FLOWGATE (42267) 8500 8000 7500 7000 6500 6000 5500 5000 4500 4000 MW 3500 3000 2500 2000 1500 1000 500 0-500 -1000-1500 S-to-N 1Jul 2Jul 3Jul 4Jul 5Jul 6Jul 7Jul 8Jul 9Jul 10Jul 11Jul 12Jul 13Jul 14Jul 15Jul 16Jul 17Jul 18Jul 19Jul 20Jul 21Jul 22Jul 23Jul 24Jul 25Jul 26Jul 27Jul 28Jul 29Jul 30Jul 31Jul Date Source: 15-minute average of 5-minute instantaneous readings via SCADA Sep 21, 2010 24
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Northwest-Idaho Rated in both directions, W>E most important for Idaho load service No ATC available W>E, either on Idaho system or on BPA system directly to the west Relief project: Boardman to Hemmingway 500 kv project Sep 21, 2010 26
Northwest-Idaho Cold Dec 2008 Negatives: E>W Flow (Rating 2400 MW) IDAHO-PNW FLOW HOURLY LOADINGS: 01DEC08-31DEC08 W-to-E IDAHO-PNW FLOW (300010) 0-100 -200-300 -400-500 -600-700 -800 MW -900-1000 -1100-1200 -1300-1400 -1500 1Dec08 1Dec08 2Dec08 2Dec08 3Dec08 3Dec08 4Dec08 5Dec08 5Dec08 6Dec08 6Dec08 7Dec08 8Dec08 8Dec08 9Dec08 9Dec08 10Dec08 10Dec08 11Dec08 12Dec08 12Dec08 13Dec08 13Dec08 14Dec08 15Dec08 15Dec08 16Dec08 16Dec08 17Dec08 17Dec08 18Dec08 19Dec08 19Dec08 20Dec08 20Dec08 21Dec08 22Dec08 22Dec08 23Dec08 23Dec08 24Dec08 24Dec08 25Dec08 26Dec08 26Dec08 27Dec08 27Dec08 28Dec08 29Dec08 29Dec08 30Dec08 30Dec08 31Dec08 31Dec08 Date Sep 21, 2010 27
Northwest-Idaho Hot Jul 2006 On peak W>E, off-peak E>W (Rating W>E ~ 1100-1200 MW) IDAHO-PNW FLOW HOURLY LOADINGS: 01JUL06-31JUL06 W-to-E IDAHO-PNW FLOW (300010) 1100 1000 900 800 700 600 500 400 300 200 100 MW 0-100 -200-300 -400-500 -600-700 -800 1Jul06 1Jul06 2Jul06 2Jul06 3Jul06 3Jul06 4Jul06 4Jul06 5Jul06 5Jul06 6Jul06 6Jul06 7Jul06 8Jul06 8Jul06 9Jul06 9Jul06 10Jul06 10Jul06 11Jul06 11Jul06 12Jul06 12Jul06 13Jul06 14Jul06 14Jul06 15Jul06 15Jul06 16Jul06 16Jul06 17Jul06 17Jul06 18Jul06 18Jul06 19Jul06 19Jul06 20Jul06 21Jul06 21Jul06 22Jul06 22Jul06 23Jul06 23Jul06 24Jul06 24Jul06 25Jul06 25Jul06 26Jul06 27Jul06 27Jul06 28Jul06 28Jul06 29Jul06 29Jul06 30Jul06 30Jul06 31Jul06 31Jul06 E-to-W Date Source: Integrated hourly data via RODS accounts Sep 21, 2010 28
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Montana-Northwest Main flow and constraint E>W, small amount of ATC available Sized for existing generation Colstrip, some Montana hydro Sep 21, 2010 30
Montana-Northwest Cold Dec 2008 W-to-E MONTANA-PNW FLOW Actual Loadings and OTCs: 01Dec08-31Dec08 (31 Days) MEAN 15-MINUTE FLOW: NWE-PNW MW (36920) MEAN 15-MINUTE OTC: NWE-PNW W-E LIMIT MW (62830) MEAN 15-MINUTE OTC: NWE-PNW E-W LIMIT MW (62828) 1600 1400 1200 1000 800 600 400 200 0-200 MW -400-600 -800-1000 -1200-1400 -1600-1800 -2000-2200 -2400 E-to-W 1Dec 2Dec 3Dec 4Dec 5Dec 6Dec 7Dec 8Dec 9Dec 10Dec 11Dec 12Dec 13Dec 14Dec 15Dec 16Dec 17Dec 18Dec 19Dec 20Dec 21Dec 22Dec 23Dec 24Dec 25Dec 26Dec 27Dec 28Dec 29Dec 30Dec 31Dec Date Source: 15-minute average of 2-second SCADA readings via PI Sep 21, 2010 31
Montana-Northwest Hot Jul 2006 MONTANA-PNW FLOW HOURLY LOADINGS: 01JUL06-31JUL06 W-to-E MONTANA-PNW FLOW (300011) MW E-to-W 1200 1100 1000 900 800 700 600 500 400 300 200 100-100 0-200 -300-400 -500-600 -700-800 -900-1000 -1100-1200 -1300-1400 -1500-1600 -1700-1800 -1900-2000 -2100 1Jul06 3Jul06 5Jul06 7Jul06 9Jul06 11Jul06 13Jul06 15Jul06 17Jul06 19Jul06 21Jul06 23Jul06 25Jul06 27Jul06 29Jul06 31Jul06 Date Source: Integrated hourly data via RODS accounts Sep 21, 2010 32
Questions? Sep 21, 2010 33