Emerging Technologies Integration in ERCOT 2012 ERCOT Operations Seminar Mark Bruce Principal Stratus Energy Group

Introduction The recent regulatory paradigm shift to an open access common carrier network system coupled with a variety of economic, environmental, and policy factors have led to significant and widespread investment in an array of new technologies which offer substantial opportunities but also pose fundamental challenges to the planning and operation of the ERCOT bulk electric system.

Objectives At the completion of this course of instruction you will: Recognize an array of emerging technologies currently in various stages of market entry on the ERCOT system Understand the high-level opportunities and challenges such technologies pose for the ERCOT system from the planning and operations perspectives

Technologies Surveyed Wind Solar Compressed Air Energy Storage Battery storage Demand response Distributed generation Future technologies

System Challenges Load Forecasting Generation Scheduling Ancillary Services Procurement/Dispatch Primary Frequency Response System Inertia Network Model and Planning Models Interoperability and Integration

Emerging Technology Drivers Public Policy Private and Public Investment Technical Challenges Technological Advances Environmental Considerations Economic Factors

Wind: capacity growth

Wind: energy growth Cumulative wind energy in ERCOT – Jan June 2009

Wind: dispatch The evolution of wind energy dispatch Early Zonal: Wind scheduled and dispatched by QSEs who accounted for wind in SCE. Late Zonal: Wind scheduled and dispatched by QSEs and ERCOT offset wind SCE through BES adjustments immediately prior to operating interval. Nodal: WGR base point set by SCED equal to HSL which is equal to WGRPP minus curtailment.

Wind: forecasting Evolution of wind forecasting in ERCOT QSEs used own forecasting methodologies with widely varying accuracies. Bifurcation of DA and RT forecasts DA models and RT persistence Development of independent ERCOT forecast Nodal: Single, independent forecast which integrates historical data, forecasted performance, and RT site-specific telemetry.

Wind: forecasting

Wind: technical standards The technical requirements for WGRs have evolved over time in ERCOT. Voltage Ride-Through Reactive Power Capability Ramp rate limitations Performance Metrics

243 MW decrease in 14 sec Responsive Reserve Deployed source: ERCOT

Wind: CREZ implementation

Wind: market impacts Price impacts PTCs weigh on LMPs Forward markets Bilateral market Some element of RT volatility Long term resource adequacy impacts

Wind: multiple profiles West, North, South/Coastal

Wind: limits to DG wind growth Land use / zoning Scale / capacity factor Geography / wind profile Cost to benefit ratio Technology limitations relative to others

Wind: remaining challenges WGR modeling WGR planning horizon HA forecasting / RT awareness Net Load swings

Solar: different technologies PV Concentrating Thermal hydraulic Thermal storage Inverter technologies Associated turbine technologies

Solar: opportunities PTCs and ITCs weigh on LMPs Greater coincidence with peak demand

Solar: system issues Similar to wind Modeling Performance metrics Forecasting Inertia Solar DG is under the radar

Energy Storage: technologies CAES Batteries Flywheels Pumped hydro Thermal mass

Energy Storage: CAES

Energy Storage: batteries Various battery types Applications range from tens of MW to small kW capacities. Typically of limited duration Typically have need to cycle to some significant depth of discharge

Energy Storage: rules matter Is it a generator, a load, or a transmission or distribution system device? Yes. Presidio NaS battery treatment SB 963, 82 nd Texas Legislature PUCT Rules ERCOT Protocols and OBDs

Energy Storage: specs Very different technologies have very different capabilities as generation resources and as load resources Likely to have very different roles in the market and, therefore, in system operations

Flywheel Regulation Example A fossil plant following a regulation command signal Energy Storage accurately following a regulation command signal

Demand response Small customer-owned systems Larger, more complex DR aggregations DR as defined market services Storage as DR HAN-enabled devices RT price awareness Load forecast impacts

Residential Large C&I Both days were Wednesdays Customer class breakdown is for competitive choice areas only IDR meters are required at >700kW Hot day, high A/C load ERCOT load for this hour: 63,594 MW ERCOT load for this hour: 30,697 MW 21,000 MW of residential summer peak load Moderate day, low A/C load

Distributed Generation Limits to wind DG growth Accelerating solar DG growth Steady UPS systems growth Lack of holistic DG awareness

Future Applied Technologies? Electric Vehicles (EVs) Wide-scale RT price-sensitivity coupled with demand elasticity Ubiquitous thin-film solar applications Mass commercial import/export capability

Summary An array of emerging generation, storage, and demand response technologies present both opportunities and challenges to the ERCOT system. Capturing benefits while mitigating risks requires awareness and flexibility.

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