PUCT Staff File Draft Concerning Treatment of Energy Storage Transactions

PUCT Staff have filed a draft recommendation for a proposal for publication which would provide that energy storage equipment or facilities would be settled at the node when charging, and that such transactions would be considered wholesale transactions and would generally not be subject to ancillary costs (39917).

Specifically, the draft would provide that the purchase of electricity by an owner or operator of electric energy storage equipment or facilities is a wholesale market transaction if the electricity is separately metered and converted to another form of energy and stored by electric energy storage equipment or facilities solely for later re-generation and re-sale as energy or ancillary services.

For the settlement of such purchase, under the draft, ERCOT shall use the nodal energy price at the electrical bus that connects the electric energy storage equipment or facility. Such purchase shall not be subject to retail tariffs, rates, and charges or fees assessed in conjunction with the retail purchase of electricity. Such purchase shall be subject to ERCOT settlement but shall not be subject to ERCOT charges or credits associated with ancillary service obligations, except if such purchase occurs during a system emergency declared by ERCOT and ERCOT did not direct that such purchase occur.

The proposal would also provide that the storage facility will be included in the 4CP calculation for wholesale transmission rates and charges if it withdraws electricity during the 4CP intervals.

Staff proposed seeking stakeholder comment on how the proposed rule should address the situation where there is retail load or other generation facilities behind the transmission system point of delivery at which energy storage equipment or facilities are located.