1. MIT tour of the California ISO Control Center March 31, 2015
Clyde Loutan, California ISO --- Sr. Advisor, Renewable Energy Integration

2. California ISO is the largest of ten BAs in California and now operates in seven western states
Energy and environmental goals drive change
New operating conditions emerge
Flexible resource capability
Advanced technologies
Demand Response, Storage and Energy Efficiency
Vehicle to Grid Integration
65,226 MW of power plant capacity (net dependable capacity)
50,270 MW record peak demand (July 24, 2006)
30 million people served
$10 billion annual market
80% of the load served in California

3. California ISO faces unique challenges driven by success of state initiatives and environmental policies
Greenhouse gas reductions to 1990 levels by 2020
Limits on availability of air emission credits for replacement generation
33% of load served by renewable generation by 2020 (50% by )
Possibly 12,000 MW of distributed generation by 2020
Less predictable load patterns – rooftop solar, electric vehicles, and smart grid
Scheduled phase out of approximately 12,000 MW of once- through cooling in coastal power plants
Delta bay plan managing water flow affecting hydro availability
Slide 3

4. Solar production varies from one day to the next --- first week of March 2014
4,500
4,000
3,500
3,000
Average
2,500 MW
2,000
1,500
1,000
500 6 7 8 9 10 11 12 13 14 15 16 17 18
-500
Day_1
Day_2
Day_3
Day_4
Day_5
Day_6
Day_7
Average

5. Wind production varies from one day to the next --- first week of March 2014
3,500
3,000
2,500
2,000 MW
1,500
Average
1,000
500 1 2 3 3 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23
Day_1
Day_2
Day_3
Day_4
Day_5
Day_6
Day_7
Average

6. A Balancing Authority (BA) is responsible for operating a transmission control area
Electricity is produced, delivered, and consumed at the speed of light.
The ISO balances the system in two timeframes:
Market down to 5-minute resolution
AGC on a 4-second basis
WECC is the regional entity for the provinces of Alberta and British Columbia, the northern portion of Baja California, Mexico, and all or portions of the 14 Western states between
Let’s start with some terminology – A balancing authority, or BA is responsible for operating a transmission control area. This picture of the western interconnection represents the 38 BAAs or balancing authority areas.
The key here is that BAs match load with generation. They are responsible for maintaining “balance” of load and generation. When there is more load, for example people turning on lights, than generation there is an “imbalance” between the two. More generation must be called upon, or “dispatched” to resolve the imbalance. Currently many balancing authorities will make sure that they have extra generation on hand and will manually dispatch generation to resolve the imbalance. The energy imbalance market is another, more efficient way to maintain balance.
PacifiCorp BAs are among the BAs list shown on this slide. The California ISO is a balancing authority also. However we are a little different from other balancing authorities in the west (except for Alberta) in that we use multi-party centralized market to balance wholesale supply and demand as opposed to an informal, bi-lateral market. Our market, is automated and runs every five minutes. It looks at all the load that needs to be served, all the available generation and optimizes the dispatch in the most efficient way considering the cost of the generation and the potential congestion on the transmission lines.
Slide 6

7. To be prepared for increased supply variability, fleet flexibility requirements to be understoodMW
Generation Requirement
Hour Ahead Schedule
And Load Following
Regulation
Hour Ahead
Adjustment
Load Following
Day Ahead
Hour Ahead
How do we make operating decisions?
Operating Timelines?
Load – DA errors, HA errors, RT errors
Wind – DA errors, HA errors, RT errors
Solar – DA errors, HA errors, RT errors
Stochastic variations among the three
Autocorrelation
Cross correlation
Schedule
Schedule t
Operating Hour
ISO 33% RPS Study of Operational Requirements and Market Impacts

8. Balancing Authority ACE limit (BAAL)
BAAL is designed to replace CPS2
Control opposes frequency deviation
BAAL relaxes area regulation needs
ACE is allowed to be outside BAAL for up to 30 minutes
Slide 8

9. The ISO has already begun to experience the need for flexible resources
Load, Wind & Solar Profiles
---
Base Scenario
January 2020
34,000
9,000
7,000 MW in 3-hours
32,000
6,700 MW in 3-hours
8,000
Load & Net Load (MW)
30,000
7,000
Wind & Solar (MW)
28,000
6,000
26,000
5,000
24,000
4,000
22,000
12,700 MW in 3-hours
3,000
20,000
2,000
18,000
16,000
1,000
14,000
Net_Load
Load
Wind
Total Solar
Net Load = Load - Wind - Solar
Slide 9

10. Load, Net Load, Wind & Solar --- 06/30/2014
Solar production is significantly reducing the need for conventional resources on peak demand days
Load, Net Load, Wind & Solar /30/2014
43,000
5,200
40,424 MW
4,634 MW
41,000
4,800
39,000
4,400
37,000
4,000
35,000
3,600
33,000
3,200
31,000
Wind & Solar (MW)
2,800
29,000
Load & Net-Load (MW)
2,400
27,000
2,000
25,000
1,600
23,000
1,200
21,000
19,000
800
17,000
400
15,000
Load
NetLoad
Wind
Solar
Net Load (Red Curve) = Load - Wind - Solar
Slide 10

11. ISO’s net-load vs. actual RTD energy prices for April 12, 2014
Energy prices were zero or negative for 43% of the 5-minute RTD intervals
Slide 11

12. Negative energy prices indicating over-generation risk start to appear in the middle of the day during high renewable production days
Increase in real-time negative prices shifting top the middle of the day
Slide 12

13. 2014 Monthly Load vs. Net Load profiles --- Weekdays

14. 2014 Monthly Load vs. Net Load profiles --- Weekends

15. 2021 Monthly Load vs. Net Load profiles --- Weekdays

16. 2021 Monthly Load vs. Net Load profiles --- Weekends

17. 2014 vs. 2021 net load distribution --- Weekdays
Potential negative RTD prices

18. 2014 vs. 2021 net load distribution --- Weekends
Potential negative RTD prices

19. Today vs. EIM Limited pool of balancing resources Inflexibility
Each BA must balance loads and resources w/in its borders.
In an EIM:
The market dispatches resources across BAs to balance energy BA BA BA BA BA BA BA BA
Limited pool of balancing resources
Inflexibility
High levels of reserves
Economic inefficiencies
Increased costs to integrate wind/solar
Diversity of balancing resources
Increased flexibility
Decreased flexible reserves
More economically efficient
Decreased integration costs
Slide 19

20. Meeting the operational challenges beyond 33% RPS with generation, storage and demand response from internal and external (EIM) resources
Storage
Generation
Voltage Support
Wider Operating Range (lower Pmin)
Regulation
Dispatchable Wind/Solar
Fast Ramping
Over Generation Mitigation
Frequency Response
Dispatchable
Quick Start
Load Shift
Peak Load Reduction
Demand Response
Slide 20

21. Questions!