April Runoff Forecasts for the Columbia Basin and Power Supply Implications Jim Ruff and John Fazio Council Meeting April 14, 2010 Boise, ID
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4 April 1 Snowpack for Columbia Basin above The Dalles, OR
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January-July Runoff Forecast 69.7 Million Acre Feet (April Forecast for The Dalles Dam) Hydroelectric Fuel Gauge 69.7 Maf is 65% of Average 95% Confidence Range is from 56 to 83 Maf
7 Recent Runoff Volumes (January-July Volume at The Dalles)
8 Lower Granite Flow Forecast
9 McNary Flow Forecast
10 Hydro System Generation
Power Supply Outlook (Approximate) Annual Load/Resource Balance Summer Sustained- Peak Reserve Margin Minimum Required0 MWa24% Critical Hydro and Firm Resources Only 300 MWa26% With this Year’s Hydro 1,400 MWa32% With Available Non- firm Resources 5,300 MWa35%
12 Power Supply Conclusions Very low chance of power outage Revenues will be lower than average Less non-firm hydro to sell Need to purchase more from the market BPA is using some of its financial reserves to get through this year Reservoir elevations at BiOp levels
13 NW Power Pool Analysis (March 5) NW Power Pool area (larger than the Council region) has adequate generation Low flows will decrease hydro flexibility Emergency measures may need to be implemented in the event of a significant resource loss and/or extreme temperature event (standard caveat)
14 Additional Slides
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Add’l. Court-Ordered Spill
17 Generation Loss due to Court-Ordered Spill
18 Runoff Distribution Used
19 Annual Hydro Generation (relative to the driest year)
20 Lower Granite Flow Forecast (in Kcfs)2010 Avg70-Yr Avg Apr Apr May73107 Jun61102 Jul2852 Aug Aug
21 McNary Flow Forecast (in Kcfs)2010 Avg70-Yr Avg Apr Apr May Jun Jul Aug Aug
22 System Generation (in GW-mo)2010 Avg70 Yr-AvgDiff Apr Apr May Jun Jul Aug Aug
23 Hydro System Generation with and without Court-ordered spill
24 Energy Value of Court-Ordered Spill MW-period Apr Apr May580 Jun318 Jul216 Aug Aug Season Avg350 MW-seas Annual Avg150 MWa
25 Court-Ordered Spill (Columbia R.) BONNEVILLE Apr10-Jun20: 100 kcfs all hours Jun21-Jul20: 85 kcfs day/ gas cap night (113 kcfs) Jul21-Aug31: 75 kcfs day/ gas cap night THE DALLES 40% of flow all hours JOHN DAY Apr 10-19: 0/60% of flow, all hours Apr 20 - Jul 20: 35% of flow, all hours (testing 30% vs 40%) Jul 21 - Aug 31: 30% of flow, all hours MCNARY Apr10-Jun14: 40% of flow Jun15-Aug31: 50% of flow (testing 40% vs. 60%)
26 Court-Ordered Spill (Snake R.) ICE HARBOR Apr3 - May1: 45 kcfs/gas cap (88 kcfs) May2 - Jul16: 30% vs. 45 kcfs/gas cap Jul17 - Aug31: 45 kcfs/88 kcfs of flow LOWER MONUMENTAL Apr3-June 20 : Gas Cap (~24-27 kcfs) all hours Jun21- Aug 31: 17 kcfs all hours LITTLE GOOSE Apr3-Aug31: 30% of flow all hours Apr24 - May7: 30% day/gas cap night (38 kcfs) LOWER GRANITE Apr3-Jun20: 20 kcfs all hours Jun21-Aug31: 18 kcfs all hours