Eversource Energy (Connecticut) interconnection application

Documents Eversource Energy (Connecticut) asks for

• Interconnection application formPowerClerk webform, e-signed Gridpol prepares this.
• Single-line diagram (one-line)One-line electrical schematic with required elements (see rejection_reasons) Gridpol prepares this.
• Site plan / site layoutStructures, metering, transformers, AC disconnect location relative to meter Gridpol prepares this.
• Inverter spec sheetTechnical data sheets
• UL 1741 / IEEE 1547 certificationProof of UL 1741 and IEEE C62.41/C62.45
• Proof of insuranceProof of liability insurance (carrier, policy no., dates, limit); $300k for 0-100 kW per Eversource table; Eversource table also lists N/A for residential inverter-based track - verify
• Other utility-specific document (when applicable)RRES: Direct Ownership or Third Party Ownership Customer Disclosure Form; payment beneficiary forms
• Final inspection sign-offMunicipal electrical inspector approval after install

How the Eversource Energy (Connecticut) process runs

1. Installer/authorized agent creates project in PowerClerk, completes interconnection application (and RRES enrollment, reviewed together), e-signs and pays fee.
2. Utility acknowledges receipt (3 business days) and checks completeness (10 business days); incomplete applications are put on hold and may be deemed withdrawn if missing items are not supplied within 15 business days.
3. Utility runs screens and issues Contingent Approval to interconnect (good-faith target 15 business days after complete application).
4. Install system; obtain municipal electrical inspector approval.
5. Utility may request commissioning/witness test within 10 business days of receiving inspector approval and schedules meter replacement/installation.
6. Utility issues Authorization to Interconnect (PTO); do not operate before.

Fees

Utility fees are paid by the installer or customer; they are not part of the Gridpol plan.

Size levels and limits

Confirm residential threshold (25 vs 50 kW) in current PURA-approved guidelines.

Storage, EV and stamps

Common issues the utility lists

• Missing/incomplete material at completeness review -> application placed on hold; withdrawn if not cured within 15 business days (joint CT residential guidelines 2.3)
• One-line must show utility voltage at main panel, fuse symbol/size feeding inverter, inverter make/model/rating, breaker ratings, isolation device location, title block with customer name/address/revision
• Isolation device must be visible and within 10 ft of main utility panel unless clearly identified with written variance

Gridpol’s pre-submission check covers these before we file.

Sources

• Eversource CT - Application to Connect: https://www.eversource.com/residential/about/doing-business-with-us/interconnections/connecticut/connecticut-application-to-connect (retrieved 2026-11-13)
• Eversource CT - Renewable Energy Solutions (RRES) Interconnections: https://www.eversource.com/residential/about/doing-business-with-us/interconnections/connecticut/renewable-energy-solutions-interconnections (retrieved 2026-11-13)
• Eversource/UI joint Guidelines for Interconnection of Residential Single Phase Certified Inverter-Based Generating Facilities (Docket 03-01-15RE03, May 2017): https://www.eversource.com/Content/docs/default-source/ct---pdfs/guidelines-residential-interconnection.pdf?sfvrsn=2 (retrieved 2026-11-13)