NOTICE DATE:  June 14, 2018

NOTICE TYPE:  W-B061418-01 Operations

SHORT DESCRIPTION:  Resource connections without relay-operated breakers (hard taps) will no longer be allowed for new Full Interconnection Studies (FIS)

INTENDED AUDIENCE:  Interconnection Entities, Resource Entities, and Transmission Service Providers

DAY AFFECTED:  June 14, 2018

LONG DESCRIPTION:  ERCOT has recently observed an increase in proposals to directly interconnect All-Inclusive Generation Resources to transmission lines without using relay-operated breakers (commonly referred to as “hard taps”).  After careful consideration, ERCOT has determined that this method of interconnection will not be permitted going forward because it presents an unnecessary risk that an unexpected loss of the All-Inclusive Generation Resource may result in the loss of part of the ERCOT System. 

ERCOT intends to address this concern as follows:

1.    For any Full Interconnection Study (FIS) or FIS study element submitted on or after May 31, 2018, ERCOT will not accept the study if it proposes a hard-tap interconnection for any All-Inclusive Generation Resource, whether that interconnection is proposed on a permanent or temporary basis.

 

2.    For any FIS or FIS study element that was submitted before May 31, 2018, if the FIS study or FIS study element submitted before that date explicitly identifies a hard tap as a potential temporary interconnection option, and the study does not identify any reliability concern associated with the use of that hard tap, ERCOT will allow the All-Inclusive Generation Resource to use the proposed hard-tapped interconnection on a temporary basis only if:

·         the interconnection is not at 345 kV,

·         the use of the hard tap does not present any additional concerns that ERCOT determines could have a material reliability impact (e.g., Subsynchronous Resonance issues, stability issues including concerns affecting Generic Transmission Constraints, additional line exposure to faults, and increased severity of credible single contingencies due to loss of line and generation), and

·         the study proposes a non-hard-tapped interconnection as a permanent solution.

For any such FIS, ERCOT will consult with the relevant Transmission Service Provider(s) (TSP) and the Interconnecting Entity or Resource Entity to determine an appropriate timeframe for implementing the permanent solution. 

 

3.    For any existing All-Inclusive Generation Resource interconnected to the ERCOT System using a hard tap for which no non-hard-tapped permanent solution was identified or anticipated during the interconnection process, ERCOT will allow continued use of the hard tap indefinitely unless ERCOT determines at any point in the future that the hard tap violates relevant planning criteria or operating standards. However, if such an All-Inclusive Generation Resource re-enters the Generation Resource Interconnection or Change Request process, ERCOT will require the TSP to identify a permanent interconnection solution that does not involve a hard tap as part of the FIS study. 

ERCOT discussed this topic at the May 31, 2018 Resource Integration workshop and also at the June 6, 2018 Wholesale Market Subcommittee (WMS) meeting and June 7, 2018 Reliability and Operations Subcommittee (ROS) meeting, and is providing this Notice to inform Market Participants of this determination.

CONTACT:  If you have any questions, please contact your ERCOT Account Manager. You may also call the general ERCOT Client Services phone number at (512) 248-3900 or contact ERCOT Client Services via email at [log in to unmask].

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