1. Jim Mcintosh Director, Executive Operations Advisor California ISO
Power Association of Northern California Maintaining Grid Reliability In An Uncertain Era May 16, PG&E Conference Center
Jim Mcintosh
Director, Executive Operations Advisor
California ISO

2. 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.

3. Policy Drivers
State law AB32 – reduction of greenhouse gas emissions to 1990 levels by 2020
Western Climate Initiative
20% Renewable Portfolio Standard (RPS) by
33% RES by 2020 (Executive Order)
Repowering or replacement of once-through cooling power plants (~34% of in-state gas and nuclear capacity)

4. Additional Supply Side Policies
Small-scale renewable feed-in tariff program
Resources must be smaller than 1.5 MW and the cap is MW
Storage bill AB2514 (Sept. 2010)
Requires the CPUC to consider and adopt procurement targets for viable and coast-effective energy storage systems.

5. Location of OTC plants in local capacity requirement (LCR) areas within CAISO
*Retired out 2010

6. The 2-3 year look-ahead: renewable resource portfolios in 2006 and 2012 (20% RPS), by capacity (MW)

7. 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
2. Synchrophasors are the most significant advancement in control center technology in the last 30 years.

8. 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 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

9. Challenges of Fossil Fuel and Wind Generation
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
GRID OPERATORS
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
WIND GENERATORS

10. Wind activity across a 24 hour period.
Difficulty of Predicting Wind Energy
Total Wind Generation
1600
1400
1200
1000 MW
800
Average
600
Averages
Planning decisions
Policy decisions
400
200 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.

11. 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
Load MW
600
Wind/Solar MW
30,000
500
28,000
400
300
26,000
200
24,000
100
22,000 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

12. Photovoltaic Plant Output on a Partly-Cloudy Day
10 Second Sample – March 25, 2008

13. Requirements for Integration of Renewables
Resources Required for Renewables Integration
“Partners in Success”
Generation Portfolio
Storage
Demand Response
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

14. New record Wind production
Each cell is 2 hours
Day ahead schedule
Green is actual production
About 40 mws