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Power Association of Northern California Maintaining Grid Reliability In An Uncertain Era May 16, 2011 PG&E Conference Center. Jim Mcintosh Director, Executive Operations Advisor California ISO. The Challenges & How We Plan To Address Them. Forecasting Generation fleet characteristics
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Power Association of Northern CaliforniaMaintaining Grid Reliability In An Uncertain EraMay 16, 2011PG&E Conference Center Jim Mcintosh Director, Executive Operations Advisor California ISO
The Challenges & How We Plan To Address Them • Forecasting • Generation fleet characteristics • Ramping requirements • Ambitious environmental goals • Reliability with fewer gas powered plants • Cost containment • We need to strike a balance between reliability, renewables, and reasonable cost.
Policy Drivers • State law AB32 – reduction of greenhouse gas emissions to 1990 levels by 2020 • Western Climate Initiative • 20% Renewable Portfolio Standard (RPS) by 2012-2013 • 33% RES by 2020 (Executive Order) • Repowering or replacement of once-through cooling power plants (~34% of in-state gas and nuclear capacity)
Additional Supply Side Policies • Small-scale renewable feed-in tariff program • Resources must be smaller than 1.5 MW and the cap is 480-500 MW • Storage bill AB2514 (Sept. 2010) • Requires the CPUC to consider and adopt procurement targets for viable and coast-effective energy storage systems.
Location of OTC plants in local capacity requirement (LCR) areas within CAISO *Retired out 2010
The 2-3 year look-ahead: renewable resource portfolios in 2006 and 2012 (20% RPS), by capacity (MW) MW
The ISO grid control room faces significant short- and long-term challenges • Uncertainty of grid infrastructure development • Ramping requirements significantly increased • Continued development of control room tools • Load and wind forecasting accuracy • Rapid changes in grid generation fleet, especially wind and solar technologies 1. Wind and solar variability will be a significant issue by 2012-2013. 2. Synchrophasors are the most significant advancement in control center technology in the last 30 years.
These challenges can be addressed through improved control room tools (Synchrophasors) and training • Wind and solar modeling & production forecasting • State estimator solution & accuracy • Grid reliability & engineering studies • Network and market modeling • Awareness of regional disturbances (e.g. 1996 event) • Dynamically assess the grid (EMS not sufficient) • 30 samples per second compared to once every four seconds • Can increase COI transfer by 1500 MW • Estimated reduction in congestions costs $250 million • Better real time visualization
Challenges of Fossil Fuel and Wind Generation GRID OPERATORS WIND GENERATORS • Predictability • No surprises • Dependable energy schedules • Accurate forecasts • Contingency reserves available • Generators that follow dispatch commands • Excellent tools for visibility of system status • High quality data • De-rate information on units is timely and accurate • Hard to predict • Shows up unscheduled • Maximum generation at night when loads are low and there is no place for the energy • Large ramp changes both up and down • Lack of good data from wind generation facilities • Lack of visibility on what wind generations are doing • Don’t follow dispatch commands ---treated as “Must Take” generation
Difficulty of Predicting Wind Energy Total Wind Generation 1600 1400 1200 1000 MW 800 Average 600 400 200 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Wind activity across a 24 hour period.
RAMPING! CAISO Load vs. Total Wind Summer 2006 Load Total Wind Solar 40,000 1,200 1,100 38,000 1,000 36,000 900 34,000 800 700 32,000 MW MW 600 Wind/Solar Load 30,000 500 28,000 400 300 26,000 200 24,000 100 22,000 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 Hours Wind generation tends to be inversely correlated to daily load curve, creating ramping impacts
Photovoltaic Plant Output on a Partly-Cloudy Day 10 Second Sample – March 25, 2008
Requirements for Integration of Renewables Resources Required for Renewables Integration “Partners in Success” GenerationPortfolio Storage DemandResponse Wind Generation Hydro Generation Quick Start Units Fast Ramping Wider Operating Range (lower Pmin) Regulation capability Shift Energy from off-peak to on-peak Mitigate Over Generation Voltage Support Regulation capability Price sensitive load Responsive to ISO dispatches Frequency Responsive Responsive to Wind Generation Production Geo-thermal Generation Solar Generation
New record Wind production Each cell is 2 hours Day ahead schedule Green is actual production About 40 mws