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

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, 2006) 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 1990 levels

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

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

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

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)

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