This article outlines the interconnection process for large load projects in New York, such as data centers. The New York Independent System Operator (NYISO) oversees this process, which includes multiple stages to evaluate the impact of new connections on the transmission system and to establish the necessary upgrades.
Below, you will find a summary of key points regarding deposits and refunds, as well as a detailed timeline of each stage of the interconnection process.
Key Points
- No Deposit for Study Request: No upfront deposit is required for the initial Study Request (Page 18).
- System Impact Study (SIS) Deposit: $40,000-150,000. SIS costs are invoiced monthly and deducted from the study deposit. Any unused portion of the deposit is refunded after cost reconciliation (Pages 13–14).
- Facilities Study (FS) Deposit: A $100,000 deposit is required for the FS. The developer is responsible for the actual costs, which are invoiced monthly. The $100,000 deposit remains intact unless used to cover unpaid invoices and is refunded in full at the conclusion of the FS, provided all invoices are paid (Page 14).
Timeline
- Submission of Interconnection Request
- Action: The Transmission Owner (TO) or customer submits a written request to NYISO for a System Impact Study (SIS).
- Deposit: No upfront deposit is required.
- Timeline: Day 0 (submission initiates the process).
- TEI Manual Excerpt (Page 18):
"The TO proposing the project (i.e., the Eligible Customer) initiates the SIS process by submitting a SIS Request...The TO is not required to provide a fee or deposit with the Study Request."
- Determination of SIS Requirement
- Action: NYISO evaluates whether an SIS is necessary based on the project's impact, including:
- Reducing NYISO interface transfer capability by more than 10 MW.
- Increasing transfer capability by more than 25 MW.
- Changing the classification of affected facilities (e.g., NPCC BPS facilities).
- Timeline: 7–30 calendar days after receiving complete information from the customer.
- TEI Manual Excerpt (Page 17):
"An SIS will be required if the project either (i) reduces the transfer capability of a NYISO interface by greater than 10 MW or increases the transfer capability of a NYISO interface by greater than 25 MW; or (ii) changes the classification of affected facilities to NPCC BPS facilities." - Refundability: Not applicable at this stage.
- System Impact Study (SIS)
- Action: Conduct a detailed SIS to assess impacts on reliability, transfer capability, and any required Network Upgrades.
- Deposit: A $150,000 study deposit is typical, covering NYISO's coordination and initial SIS costs.
- Timeline:
- NYISO prepares the draft Scope of Work (SIS Scope) for review by TPAS and OC: ~1–2 months.
- Customer executes the SIS Agreement within 15 days of issuance.
- SIS completion: ~90–120 days, depending on scope.
- TEI Manual Excerpt (Page 12):
"NYISO prepares and tenders a SISA to the Customer...The Transmission Developer is required to provide a study deposit of either $40,000 (if the Transmission Developer is hiring a third-party consultant to perform the analytical portions of the study) or $120,000 (if NYISO is responsible for performing the entire study)." - Refundability: Any remaining balance from the deposit, after deducting actual incurred costs, is refunded with accrued interest (Page 13).
- Facilities Study (FS)
- Action: Following the SIS, the customer may proceed with an FS to refine descriptions and cost estimates for required Network Upgrades.
- Deposit: $100,000.
- Timeline:
- NYISO issues the FS Agreement within 15 business days after SIS approval.
- Customer executes the agreement within 30 calendar days.
- Study completion: ~90 days.
- TEI Manual Excerpt (Page 14):
"The Transmission Developer is required to provide a study deposit of $100,000 to the NYISO on or before return of the executed FSA." - Refundability:
"During the course of the FS, NYISO holds the $100,000 deposit on account and invoices the Transmission Developer monthly for NYISO and CTO(s) study costs. After the FS is completed and all invoices for study work have been settled, NYISO initiates final accounting, billing, and refunds any unspent portion of the deposit as part of the final billing."
- Construction Phase
- Action: Customer proceeds with construction based on FS results.
- Requirements:
- Security deposits covering Network Upgrade costs.
- Execution of construction agreements with the Transmission Owner (TO).
- Timeline: Begins upon execution of construction agreements.
- TEI Manual Excerpt (Page 22):
"After completion of the FS, the Customer may elect to proceed with the construction of the Facilities...and provide each affected TO security acceptable to the TO for the cost of the new facilities or upgrades." - Refundability: None at this stage.
Reference: NYISO TEI Manual
