ERCOT Files NPRR to Implement Loads in SCED

ERCOT has formally submitted for approval Nodal Protocol Revision Request 555, Load Resource Participation in Security-Constrained Economic Dispatch.

If approved, NPRR 555 would enable demand response from Controllable Load Resources, as re-defined by the NPRR, to be dispatched by security-constrained economic dispatch (SCED) based on a Real-Time Market Energy Bid.

Participation in SCED will allow load resources to contribute to price formation by setting a price based on their opportunity cost or the value of lost load, and will provide participating Qualified Scheduling Entities (QSEs) and load resources with price certainty in the form of SCED Base Point instructions, ERCOT said.

About 75% of the ERCOT load across the peak hour of a typical summer peak day is load from the residential and small commercial sectors. These loads cannot currently participate in SCED, but NPRR 555 provides a platform for these loads to "bid to buy" and be a part of the price formation. QSEs can use these new load resources as a means to hedge against generation resource outages, ERCOT said. How much of this load will be able to be controlled is yet to be determined, but the implementation of this NPRR is the first step in providing a platform for load participation of this type, ERCOT said.

The NPRR clarifies the initial rules for participation in the RTM by newly-defined Aggregate Load Resources (ALRs), consisting of multiple metered sites within a single ERCOT Load Zone. Controllable Load Resources, including ALRs, must be capable of responding to five-minute SCED Base Point instructions, which could instruct load changes in either direction (up or down) if the Controllable Load Resource's bid sets the Locational Marginal Price (LMP).

The NPRR, along with associated Other Binding Documents, also establishes a long-term solution for Controllable Load Resource provision of Non-Spinning Reserve (Non-Spin) Service by allowing participating Controllable Load Resources providing Non-Spin to be dispatched economically. Initial participation will be limited to Load Serving Entity (LSE) QSEs (the only QSEs that can submit bids to buy energy) and Controllable Load Resources capable of responding to five-minute SCED Base Points.

As submitted, the NPRR proposes uniform performance and compliance metrics for any Load Resource participating in SCED.

ERCOT has authored NPRR 555 as a way of contributing to ongoing efforts by policymakers and market participants to help limit Real-Time price reversal when actions are taken by ERCOT for reliability purposes (in this case, deployment of Load Resources providing Non-Spin).