ERCOT's Aggregated Distributed Energy Resource (ADER) pilot grew from just 8 MW of discharge capacity in June 2025 to 171 MW in September 2026, with 341.2 MW of total qualified capacity.

On December 7, ERCOT's Board votes on Phase 4 of the pilot. Phase 4 adds a storage-only option that SCED dispatches by node and that no ERCOT-wide cap limits. However, it still pays these batteries the load zone price, excludes them from ancillary services, and leaves distribution utilities to manage the local impacts.

Key takeaways

• Nine ADERs are qualified to provide 341.2 MW as of September 2026. ERCOT counts both charging and discharging capability toward that figure, so the fleet can discharge about 171 MW.
• ERCOT raised the pilot's capacity limit from 200 MW to 500 MW on March 2, 2026. Qualified capacity has more than doubled since.
• From February to July 2026, ADERs earned 40% as much wholesale revenue as grid-scale BESS per MW of discharge capability. This largely reflects limits on market participation and the fact that, for aggregators, the batteries first serve to keep their own retail customers' power on.
• Phase 4 creates the Aggregate Distributed Energy Storage Resource (ADESR), dispatched on nodal shift factors with state of charge telemetry and no ERCOT-wide cap. WMS reviews it on November 4 and TAC on November 18.
• Nodal dispatch with zonal settlement, distribution visibility, retail access for co-op and municipal customers, and ancillary service eligibility all remain open.

How the ADER pilot works

An ADER is a group of homes or small sites that a Qualified Scheduling Entity (QSE) offers into ERCOT as one resource. Most of the capacity in the pilot belongs to residential battery aggregators.

Each ADER registers as an Aggregate Load Resource. As of October 2026, it settles at its load zone price, not at a node. When a home battery exports, ERCOT treats the export as negative load.

This load-based model also sets how ERCOT counts ADER capacity. The pilot's Governing Document defines an ADER's capability as "Demand response capability plus injection capability". For a battery fleet, that capability spans the full swing from charging to discharging. A fleet that can charge at 50 MW and discharge at 50 MW moves its net load by 100 MW, so it registers 100 MW.

ERCOT raised the pilot’s cap from 80 MW to 500 MW in three steps between June 2025 and March 2, 2026, and now lets a single QSE hold up to 90% of any limit, up from 50%. Non-Spinning Reserve (Non-Spin) and ERCOT Contingency Reserve Service (ECRS) stay capped at 100 MW each, and qualified ECRS already sits at that limit.

Base Power holds most of the pilot

ERCOT masks participant names in its Limits of Participation file. Matching each row to SCED resources by load zone, MW and telemetry gives Base Power 173.4 MW of the 248.7 MW approved on June 1, 2026. Tesla held 49.3 MW and bp 10.2 MW. Bandera Electric Cooperative runs a 1.6 MW ADER near Boerne.

Base Power's own count, on a discharge basis, is 103 MW of the program's 145 MW in August 2026. That 145 MW is half of the 292.9 MW ERCOT reported as qualified that month, consistent with ERCOT counting both directions. Both sources put Base Power's share at about 70%.

Base Power is a retail electric provider (REP). It owns the batteries, installs them for a one-time fee and charges customers a monthly membership plus an energy rate. In return, customers get backup power. It raised $1 billion in August 2026.

Many home batteries sit outside the pilot

The ADER pilot does not capture every home battery that responds to Texas grid conditions. Base Power also runs programs for CoServ (100 MW) and Guadalupe Valley Electric Cooperative (50 MW). In these programs, the utility dispatches the batteries to cut its own peak demand and transmission charges. None of this capacity appears in ADER data.

The rest of this article covers how the pilot batteries actually operate and what Phase 4 would change:

• How Base Power's two-step bid curve lets it set its own dispatch in SCED, five minutes at a time.
• A full operating day for Base Power's Houston ADER, and how its cycling tracked real-time price spreads from February to July 2026.
• What ADERs earned per MW of discharge capability against grid-scale BESS, and why the gap is likely to persist.
• How Phase 4's new storage-only resource would work, and the four questions it leaves open, including whether batteries could eventually settle at nodal prices.

How the pilot batteries have operated

So far, the aggregators decide when their ADERs charge and discharge, and ERCOT's dispatch follows.

In SCED, an ADER bids to buy power like any flexible load. Base Power consistently submits a two-step bid curve: $5,000/MWh, the offer cap, up to a breakpoint, and -$250/MWh, the floor, above it. Unless the zonal price moves outside that range, which almost never happens, SCED dispatches the ADER exactly at the breakpoint. In other words, Base Power is a price taker for exactly the net charge or discharge it wants in each interval.