The presentation will show a history of past deployments over the past 4 years. For selected events, we will discuss curtailment duration and the reason that triggered these deployments. A specific event that we will discuss occurred in February 2008 when ERCOT experienced a dramatic increase in load combined with a large drop in wind generation, which led to a system-wide deployment of Load Resources providing Responsive Reserves. We plan to conclude the presentation by discussing some of the new challenges and opportunities that Load Resources are facing as ERCOT moves from a Zonal Market Structure to a Nodal Market Structure.

When the ERCOT market first opened in July 2001, ERCOT implemented a sequential procurement process for Ancillary Services which procures four Ancillary Services (Regulation Up, Regulation Down, Responsive Reserve, and Non-Spinning Reserve). In September 2005, ERCOT modified the procuring process to simultaneously procure all the ancillary services in the Day-Ahead, with the objective to minimize the overall Ancillary Service procurement costs. Currently ERCOT is in the transition from a Zonal type market to a Nodal type market. In the future Nodal market, ERCOT will cooptimize in day-ahead the procurement of ancillary services, energy, and CRR offers/bids. In the adjustment period, the Ancillary Service capacity sufficiency and its deliverability will be evaluated; if needed, a Supplemental Ancillary Service market will be run to procure additional Ancillary Services to ensure system reliability.

An overview of ERCOT's background and the ERCOT RUC process is presented. The three steps of clearing the ERCOT RPRS Market are described. Settlements of the RPRS Market are briefly described. Finally, several typical challenges with RUC in ERCOT are briefly discussed.

Load control and demand side load management programs have been implemented in a large number of competitive power markets. These programs can provide enhanced system security and many benefits to participants. This paper reviews and compares existing economically driven programs.

The process of restructuring wholesale electric power markets in the United States has so far been very successful overall and is now entering a new phase of either fine-tuning or fundamental re-reforms of the markets. The restructured ERCOT electric power market has attracted special attention due to its particular characteristics such as its adoption of zonal portfolio model and its choice of a bilateral and ancillary service market without a spot energy market. Battling rigorously with problems and challenges constantly encountered along the way and continuously seeking for better and more efficient resolutions to improve its market, ERCOT continues to stay in the spotlight of the power industry restructuring arena. This paper gives a brief but comprehensive introduction to market operations in ERCOT, which embodies all the market policies and important changes that ERCOT has adopted since its market opening in 2001. This paper also discusses some operational challenges and market inefficiencies in ERCOT, the ongoing discussions of market redesign, and the current status of the evolution of the ERCOT market. In the end, ERCOT market is compared with California market regarding system conditions, market structure, and market operations

The movement towards restructuring in the electric industry in the United States intensifies the need for a carefully-crafted market design. Currently ERCOT is the only ISO using a zonal commercial model. The zonal model provides market participants with the ability to commit their units based on a submitted portfolio schedule; however, this model introduces several operational challenges, including constraint and deployment oscillation. By providing a useful description of some of the problems encountered within the ERCOT market and the design revisions suggested to resolve the issues, this paper can be a useful resource to policymakers in potential RTOs, especially those who are in the process of determining a market model.

Bid price overlap refers to the phenomenon that down bids are higher than up bids in a market. The ERCOT market is a bilateral market and only about five percent of energy required by the system is purchased through the ERCOT balancing energy market. The ERCOT market deploys both balancing energy up and balancing energy down services, and overlapped balancing bids exist in the market. This study provides a thorough investigation into various types of balancing bid overlap and reveals the crux of the problem. It offers solid conclusions for ERCOT power market administrators to guide market behavior by looking through the superficial phenomena and focusing on the real problem underneath. This study may be the first documentation and analysis on bid price overlap and thus provides interesting conclusions to market players in various fields.

This paper introduces the ERCOT Balancing Energy Market, which consists of a Zonal Congestion Management Market and a Local Congestion Management Market. The ERCOT Energy market is not a fully competitive market and appropriate measures are needed to prevent monopoly prices. A decomposition method is proposed to implement the "Market Solution" measure in the ERCOT Local Congestion Market to eliminate any monopoly price. The Market Solution measure is further extended to the ERCOT Zonal Congestion Management Market to eliminate any sacrificial bids and to set feasible Market Clearing Prices that reflect the true market. A case study has been conducted using the proposed Market Solution identification method and the Market Clearing Price recalculation method.