Incentives & Policy

Interconnection Agreement

An interconnection agreement is a formal contract between a solar system owner and the local utility that establishes the technical and legal terms for connecting the solar system to the utility grid. It is required for every grid-tied solar installation and must be approved before the system can legally operate and export power.

The interconnection process typically involves submitting an application to the utility with system specifications (panel wattage, inverter model, electrical one-line diagram), paying an application fee, passing utility review for grid compatibility, completing the solar installation and passing local electrical inspection, receiving utility approval to operate (Permission to Operate or PTO), and having a bidirectional net meter installed.

The timeline from application to Permission to Operate varies widely by utility — from a few weeks for streamlined programs to several months for utilities with backlogged queues or complex review processes. Delays in interconnection are one of the most common frustrations in residential solar installation, as the system cannot legally generate power until PTO is granted.

Interconnection agreements specify technical requirements including anti-islanding protection, power quality standards, maximum system size relative to the service panel, insurance requirements, and the utility's right to disconnect the system for grid safety or maintenance. They also establish the terms for net metering credits or export compensation.

Most states have standardized interconnection procedures for small residential systems (typically under 25 kW) that simplify the process. Larger commercial systems may face more complex review processes including grid impact studies to assess whether the local distribution infrastructure can handle the additional generation capacity.

Frequently Asked Questions

Can I turn on my solar system before the interconnection agreement is approved?

No. Operating a grid-tied solar system without an approved interconnection agreement and Permission to Operate (PTO) is illegal in virtually all jurisdictions. It can result in fines, voided insurance, and safety hazards. The system must pass inspection and receive utility approval before it can legally produce power.

How long does the interconnection process take?

Timelines vary significantly by utility. Some have streamlined online applications that process in 1-2 weeks. Others have backlogs of several months. Your installer typically handles the interconnection application as part of the installation process. Ask about expected interconnection timeline before signing a contract.