PSEG Long Island Solar Interconnection Requirements and Process
PSEG Long Island administers the electric distribution system across Nassau and Suffolk counties and the Rockaways, making it the sole utility interconnection authority for residential and commercial solar installations in that service territory. This page covers the application pathway, technical requirements, and review stages that govern how solar generating systems connect to the PSEG Long Island grid. Understanding these requirements matters because errors in the interconnection process are among the most common causes of delayed solar activation on Long Island, often adding weeks or months to project timelines.
Definition and scope
Interconnection is the formal process by which a privately owned generating system — such as a rooftop photovoltaic array — obtains permission to electrically connect to a utility's distribution network and, in most cases, export surplus power to that network. For projects within the PSEG Long Island service territory, the interconnection process is governed by the PSEG Long Island Distributed Generation Interconnection Policy and is subject to oversight by the Long Island Power Authority (LIPA), the public entity that owns the transmission and distribution infrastructure.
Scope and geographic limitations: This page applies exclusively to solar projects located within the PSEG Long Island service territory — Nassau County, Suffolk County, and the Rockaway Peninsula portion of Queens. It does not cover interconnection in the Consolidated Edison service territory (which covers the rest of New York City and most of Westchester County), or in any of the upstate investor-owned utility territories such as National Grid or Central Hudson. Projects in those areas follow separate utility tariffs and New York State Public Service Commission (PSC) rules under 16 NYCRR Part 661. Distributed generation projects exceeding 5 MW in nameplate capacity are subject to transmission-level interconnection procedures outside the scope of distribution-level policy addressed here.
The regulatory context for New York solar energy systems provides a broader overview of the state-level framework within which PSEG Long Island operates.
How it works
PSEG Long Island's interconnection process follows a structured, phase-gated sequence. The process applies to both net metering customers and non-net metering export arrangements.
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Pre-application screening — The applicant or installer submits basic system specifications (address, inverter type, system size in kW-AC and kW-DC) to determine whether the proposed system falls under the simplified "Fast Track" pathway or requires a more detailed engineering study.
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Application submission — A completed interconnection application is submitted through the PSEG Long Island online portal. Required documents include a single-line electrical diagram, equipment specification sheets, a site plan, and proof of inverter UL 1741 certification. The application fee for residential systems is set by the LIPA tariff schedule.
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Initial review (completeness check) — PSEG Long Island has 10 business days to notify the applicant whether the submission is complete. Incomplete applications restart the review clock.
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Technical screening — Systems at or below 25 kW-AC that meet Fast Track criteria receive an expedited review, targeting a 15-business-day determination. Systems that fail Fast Track screening enter a supplemental review or full interconnection study queue, which can extend the timeline significantly.
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Conditional approval / Permission to Install (PTI) — Once the technical review passes, PSEG Long Island issues a PTI or conditional approval letter. Physical installation of the system may begin at this stage in most cases, though some jurisdictions require local building permits before any work starts.
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Inspection and final interconnection agreement — After installation, the local Authority Having Jurisdiction (AHJ) — typically the town or county building department — conducts its electrical inspection. PSEG Long Island then performs a utility-side inspection and issues the Permission to Operate (PTO).
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Net meter installation — A bidirectional meter is installed or remotely programmed, enabling New York net metering policy credits to begin accruing.
The full New York solar interconnection timeline varies by system size, queue position, and completeness of documentation at submission.
Common scenarios
Residential systems under 25 kW-AC: The large majority of Long Island rooftop solar installations fall into this category and qualify for Fast Track review. Systems using UL 1741-SA certified inverters with anti-islanding protection generally pass technical screening without triggering a supplemental study.
Systems between 25 kW-AC and 500 kW-AC: These require a more detailed screening against feeder capacity data. If the aggregate of existing and proposed generation on a given feeder exceeds 15% of the feeder's annual peak load, a distribution study is triggered. Study costs are borne by the applicant under LIPA tariff provisions.
Battery storage additions: Adding a battery storage system to an existing or new solar installation requires a separate interconnection amendment or a new application if the export characteristics of the system change. Inverters must carry UL 9540 certification for the storage component.
Community Distributed Generation (CDG): Projects structured as community distributed generation and sited in the PSEG Long Island territory follow a separate application track with additional contracting requirements under LIPA's CDG tariff.
For a conceptual grounding in how solar generating systems interact with the grid before entering the interconnection process, see how New York solar energy systems work.
Decision boundaries
Two primary classification boundaries determine which review pathway applies:
| Threshold | Fast Track Eligible | Study Required |
|---|---|---|
| ≤ 25 kW-AC, inverter-based, UL 1741 certified | Yes (if feeder headroom exists) | No, unless feeder screen fails |
| > 25 kW-AC or non-inverter-based | No | Supplemental or full study |
| Aggregate feeder penetration > 15% peak load | No | Distribution study mandatory |
Safety standards are non-negotiable at every boundary. IEEE 1547-2018, adopted by reference in PSEG Long Island's interconnection requirements, sets the baseline for voltage, frequency, and anti-islanding performance. Installations must also comply with NFPA 70 (National Electrical Code, 2023 edition) Article 690 and with New York solar equipment standards. Local AHJ inspections verify NEC compliance independently of the utility's technical review.
The New York Solar Authority index provides a structured entry point into all interconnection, incentive, and permitting topics relevant to Long Island and statewide solar development.
References
- PSEG Long Island Distributed Generation Tariff — official interconnection policy and fee schedule
- Long Island Power Authority (LIPA) — public owner of the T&D infrastructure; sets tariff policy
- New York State Public Service Commission — 16 NYCRR Part 661 — state interconnection standards framework
- IEEE 1547-2018: Standard for Interconnection and Interoperability of Distributed Energy Resources — technical performance baseline
- NFPA 70 / National Electrical Code, 2023 edition, Article 690 — electrical installation code for photovoltaic systems
- UL 1741 — Inverters, Converters, Controllers and Interconnection System Equipment for Use With Distributed Energy Resources — inverter certification standard
- New York State Energy Research and Development Authority (NYSERDA) — NY-Sun Program — state solar incentive program intersecting with interconnection