1. Forecasting and Operations
Austin Electricity Conference 2018
April 12, 2018
Ross Baldick,
Department of Electrical and Computer Engineering,
University of Texas at Austin

2. Outline Growth of renewables. How has this been achieved?
Where do we go from here?
The panelists:
Beth Garza, Potomac Economics,
Tim Aliff, MISO,
Guillermo Bautista, CAISO,
Sandip Sharma, ERCOT,
Arne Olson, Energy and Environmental Economics, Inc.

3. Growth of renewables.
In early 2000s, integrating even just a small amount of intermittent renewables was considered challenging.
Today, most ISOs have a significant amount of renewable generation.
Plans for more.

4. How has this been achieved?
Infrastructure,
Changes in market rules,
Wider scale balancing,
Dispatchability (down) of renewables,
Changes in operations,
Real-time data,
Improved forecasting,
Improving utilization of ancillary services,
Increasing amounts of faster responding resources.

5. Where do we go from here? Operational challenges:
Are their levels of renewable power or energy penetration that will necessitate qualitative changes in operations?
How does timing of renewable production affect integration?
Will curtailment increase inexorably?
Role of storage?
Role of dispatchable demand-side?

6. Where do we go from here? Forecasting challenges:
Are there further reductions possible in forecast errors?
More explicit representation of randomness in market, including stochastic unit commitment?

7. Beth Garza Director, Independent Market Monitor, ERCOT.
Responsible for monitoring ERCOT market participant activity, evaluating wholesale market operations, and recommending improvements to the wholesale market design.

8. Tim Aliff Director, System Wide Operations, MISO.
Oversees control room operations including dispatch, commitment, balancing, scheduling, and compliance.

9. Guillermo Bautista Director, Market Analysis and Forecasting, CAISO.
Oversees market quality analysis, market performance and reporting, price validation, calculation of reference bids, and short-term forecasting.

10. Sandip Sharma Manager, Operations Planning Group, ERCOT.
Roles in renewable integration, frequency response, ancillary services, and operational readiness.

11. Arne Olson Senior Partner, Energy and Environmental Economics (E3).
Leads E3’s Resource Planning and Asset Valuation practice areas and helps utilities, developers, government agencies, and environmental organizations to understand and cope with the impacts of clean energy policy.

12. Wind Integration in ERCOT
Beth Garza
Director, ERCOT IMM
Austin Electricity Conference
April 12, 2018

13. Thoughts on ERCOT’s Wind Generation Experience
More wind, more wind, more wind
Better reliability metrics
Reduced Ancillary Services Requirements

14. ERCOT Annual Energy by Fuel Type

15. 2017 Unit Specific Wind Generation Capacity Factor

16. Wind Output and Estimated Curtailment

17. Improved Reliability Metrics

18. Declining Requirements for Ancillary Services

19. Forecasting and Operations CAISO Case
Guillermo Bautista, Ph.D.
Director, Market Analysis & Forecasting
Austin Electricity Conference
Texas, April 2018

20. California ISO Nonprofit public benefit corporation
Part of Western Electricity Coordinating Council
65,225 MW of power plant capacity
50,270 MW record peak demand (July 24, )
26,014 circuit-miles of transmission lines
Energy Imbalance Market: Facilitates integration of renewables
2030 State Policy Goals
-50% of load served by renewables
-Double energy efficiency existing buildings
-Greenhouse gas reductions to 40% below levels

21. Percentage of load served by wind/solar, total RPS and non-carbon resources
Daily
1-minute

22. Main operational challenge for integration of renewable is about ramps and flexibility
We are four years ahead of the original estimate !

23. Increasing levels of renewable curtailments vary by season and hydro conditions
2017 Curtailment Percentage
of Potential Production
Solar: 2.8%
Wind: 1.3%
Energy Production

24. A portfolio of solutions for a plethora of challenges
Flexible Resource Adequacy
Flexible Ramp Product procured through markets
Facilitate economical participation of renewables in the markets
Regional diversity and coordination (EIM market)
Requirements for regulation and operating reserves with renewables consideration
Load and renewables forecasting improvements
Ongoing exploration to day-ahead market changes (15-minute granularity and forecast uncertainty)

25. Forecasting Challenges
Impacts on grid operations
Impact of behind the meter
Need to account for forecast uncertainty
Forecast latency
Need for probabilistic forecast

26. Renewable Integration and Adapting to the Changing Resource Mix in ERCOT
Sandip Sharma
ERCOT
Manager, Operations Planning
Austin Electricity Conference
April 12, 2018

27. Changing Resource Mix – Installed Capacity (MW)
MW please
*as of Feb. 2018

28. Addition of Flexible Gas Units

29. Key Features that further Renewable Integration
Grid Code
Renewable Forecast
Ancillary Services (Operational Reserves)
Real Time Operations

30. Wind Forecast Errors (Day-Ahead)

31. Ancillary Services
Actual Demand
Forecasted Demand
200 MW Error
Regulation
Non-Spin
Responsive
Load and generation are constantly changing, due to:
Daily load patterns
Instantaneous load variation
Changes in variable generation output
Generators tripping offline
Ancillary Services are procured in the Day-Ahead Market to ensure sufficient resource capacity is reserved which can be deployed in a timely manner to restore the balance between the load and generation.
Ancillary Services Products
Regulation Service
ERCOT sends signal every four seconds to increase or decrease output to the generators providing Regulation
Responsive Reserve Service
Capacity from generators or load resources that is readily available to respond to frequency events
Non-Spin Reserve Service
Capacity that can be started in 10 or 30 minutes to cover forecast errors or ramps

32. Discussion

33. Austin Electricity Conference Austin, Texas April 12, 2018
Achieving High Renewable Penetration with Grid-Friendly Operations
Austin Electricity Conference
Austin, Texas
April 12, 2018
Arne Olson, Senior Partner

34. 2013 California utility study found that 50%+ RPS penetrations are feasible
50% (and higher) renewable penetration is feasible, under one condition:
Renewables must be dispatchable based on the needs of the system
Renewable dispatch has little to no cost*
Lost PTC and REC values
Curtailment increases at higher penetrations
Significantly impacts economics of incremental investments
Portfolio diversity, flexible loads, flexible thermal generation, energy storage become interesting
Source: E3, “Investigating a High RPS in California,”

35. Solar can be operated very flexibly Results from CAISO/NREL/First Solar demo
Demo of 300 MW solar project in California
Solar PV resources with smart inverters and advanced plant controls can enhance reliability by providing:
Essential reliability services during periods of over-supply, e.g. Regulation
Voltage support (daytime and nighttime)
Fast frequency response
Frequency response for low and high freq. events

36. Mix of Overbuild and Storage
Optimal portfolio minimizes cost by balancing investment in solutions against increasing renewable curtailment
Mix of Overbuild and Storage
All Overbuild
All Storage

37. Over 100 GW of solar and 50 GW of storage by 2050
California’s long-term strategy looks like a mix of solar and batteries
Over 100 GW of solar and 50 GW of storage by 2050
Nearly 40 GW of solar by 2030
Electric sector reduces emissions to 20 MMT by 2050 while serving much higher loads from electrification
Other regions may have a different mix

38. Solar is the new hydro
Curtailment of solar will become routine and commonplace
Occasional spill is a reality at every hydroelectric facility
Solar can be operated very flexibly
Solar must contribute to meeting grid needs
Abundant, low-cost solar power will become the dominant issue for planning and investment in the West

39. Natural gas generation will still be needed for reliability and is a good complement to hydro/wind/solar
Gas generation is dispatched to help meet electric loads during cold weather events
Cold Winter Day under 80% Reduction
Without thermal generation, there is not enough energy to serve load during all hours
Cold Winter Day Without Gas
Production capacity
Actual production
Energy from Zero-Carbon Resources
Pacific Northwest: most challenging conditions system are multi-day cold snaps that occur during drought years
Wind and solar production tends to be very low during these conditions, even under “100%” RPS
Absent a technology breakthrough, gas generation appears to be needed for reliability

40. Thank You!
Energy and Environmental Economics, Inc. (E3) Montgomery Street, Suite San Francisco, CA Tel
Arne Olson, Senior Partner