Briefing on 2009 Summer Loads & Resources Operations Preparedness Assessment Bob Emmert Sr. Loads & Resources Engineer Board of Governors Meeting General Session May 18, 2009
In summer 2009, two key issues offset each other. ! Ongoing California drought, now in 3 rd year Supply ! Reducing California hydro capacity & energy ! Impact on supply adequacy – Negative ! Reduced peak demand Demand ! Recession impacting load ! Impact on supply adequacy - Helpful Slide 2
2009 water conditions improved since February, similar to 2008. Summary of Water Conditions May 1, 2009 (percent of average) Snow Reservoir California - Statewide Precip Water Storage Runoff Content 2009 80% 60% 80% 60% Previous Years May 1, 2008 85% 65% 85% 60% May 1, 2007 65% 25% 105% 55% Slide 3
A hydro capacity/energy derate scenario was developed for 2009. ! Hydro scenario based on: ! Derates for units dependent on large reservoir storage ! RA capacity (1-in-5) for hydro units fed directly from show melt ! 2009 Hydro capacity derate scenario NP26 hydro capacity derate 792 MW (79%) SP26 hydro capacity derate 208 MW (21%) ISO hydro capacity derate 1,000 MW Slide 4
Peak Demands were lower in 2008. Comparison of 2008 Demand to 2007 (Hot Days in August with Similar Weather) 99.0 98.2 100 50,000 48,491 44,511 80 40,000 631 Heat Index Demand (MW) 60 30,000 40 20,000 20 10,000 0 0 8/31/2007 8/29/2008 631MaxHeat Index Peak Demand Slide 5
For 2009 we used a range of economic scenarios to predict peak demand. 2009 baseline GDP forecast Slide 6
All GDP baseline forecast predicts 2009 demand 3% lower than 2008. CAISO Historical Loads and 1-in-2 Load Forecast Scenarios Excluding Pumped Storage and Water Delivery Pumping Loads 52,000 51,000 50,000 Annual Peak Demand (MW) 49,000 48,000 Economic Base Case 47,000 Economic 46,000 Scenario-1 3% 45,000 Economic 44,000 Scenario-2 43,000 Economic 42,000 Scenario-3 41,000 Economic Scenario-4 40,000 39,000 38,000 2004 2005 2006 2007 2008 2009 2010 2011 1-in-2 1-in-2 1-in-2 History Forecast Slide 7
2009 Summer planning reserve margins are more than adequate. Summer 2009 Outlook Resource Adequacy Planning Conventions CAISO SP26 NP26 Existing Generation 47,500 22,558 24,929 Retirements (Known) 22 0 22 High Probability CA Additions 1,476 378 1,098 Hydro Derates -1,000 -208 -792 Net Interchange (Moderate) 10,100 9,200 2,050 Total Net Supply (MW) 58,098 31,929 27,306 Demand (1-in-2 Summer Temperature) 45,379 25,412 21,370 DR & Interruptible Programs 2,090 1,496 593 Planning Reserve 32.6% 31.5% 30.6% Slide 8
CAISO deterministic results indicate no firm load shedding in these scenarios. CAISO 2009 Operating Reserves (Nine Deterministic Scenarios) 14,000 Operating Reserve Margin (%) 1-in-2 Demand & 1-in-2 Outages 27% 1-in-5 Demand & 1-in-5 Outages Operating Reserve Margin (MW) 12,000 1-in-10 Demand & 1-in-10 Outages 24% 21% 10,000 18% 8,000 15% 6,000 12% 9% 4,000 6% 2,000 Firm 3% Load Shedding 0 0% High Imports Moderate Imports Low Imports (11,400 MW) (10,100 MW) (8,800 MW) Slide 9
2009 probabilistic results show lower probability of shedding firm load versus 2008. Probabilities of 3% Operating Reserve Margin During Peak Conditions (firm load shedding begins) 10% 10% 3% Operating Reserve CAISO Probability of Occurrence During Peak Conditions 8% SP26 NP26 6% System & zonal are non- 4% coincident 3.8% 3.7% 2% 0.6% 0.2% 0.1% 0% 2008 2009 Slide 10
Focus of preparation for 2009: ! Extended hotter than normal summer predicted (June-August) ! Continued need for high import levels seen during 2008 ! Increased risk from fires near transmission lines Situation manageable Slide 11
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