Key Topic Concept (KTC) Number 8 KTC Title Wholesale Storage Load Treatment
Date Posted December 10, 2019
Executive Summary This KTC recommends whether provisions related to Wholesale Storage Load (WSL) treatment for battery energy storage should be modified.
Recommendation Description
WSL treatment should not be extended to Energy Storage Resources (ESRs) that are capable of self-serving retail Load, such as Private Use Network (PUN) Load, with the stored energy.
BESTF Discussion On 11/15/19, ERCOT staff presented on KTC 8 item 1, which asked about the appropriateness of WSL treatment for batteries located within PUNs.
On 12/6/19, the BESTF reached consensus on KTC 8 item 1.
TAC Action Requested BESTF plans to request at the 1/29/20 TAC meeting a vote to approve KTC 8 item 1.
TAC Action Summary
Proposed KTC Recommendation Language
Key Topic/Concept recommendation Language for TAC Approval
1/29/20 TAC Meeting:
The BESTF acknowledged the language in PUC Subst. Rule 25.501 (m) which states that WSL occurs when stored energy is “subsequently re-generated and sold at wholesale as energy or ancillary services.” Based on this provision in Rule,
a battery that serves retail Load behind its Point of Interconnection should be ineligible for WSL treatment.
None.
Key Topic/Concept
recommendation Language Previously Approved by tac
None.
Key Topic/Concept
recommendation Language IN DISCUSSION AT BESTF
None.
Future Decision Points and Issues for Developing Key topic/Concept recommendation Language
Item #2 in KTC-8 asks: Should WSL treatment implementation extend to non-dispatched generators? If yes, should there be differentiation between a SOG that is co-located with customer load and one that only has auxiliary loads behind the metering point?
Settlement Only Energy Storage is not yet a defined term, pending future NPRR submissions by the Resource Definition Task Force (RTF). Under current rules, a battery with capacity >1 MW that injects to the grid would register with ERCOT as a Settlement Only Distribution Generator or Settlement Only Transmission Generator. The BESTF has
deferred discussion on WSL treatment for these resources until sometime early next year.
Applicable Protocol Section(s)
Impacted System(s) / Application(s)