Interconnection Agreement

An interconnection agreement is a formal contract between a solar system owner and their electric utility that establishes the terms and conditions for connecting a solar energy system to the public power grid. It is a required step for all grid-tied solar installations.

The interconnection agreement covers technical requirements (system size limits, safety equipment, insurance), operational rules (net metering terms, maintenance responsibilities), and liability provisions. Your solar installer typically handles the interconnection application on your behalf as part of the installation process. The application includes system specifications, single-line electrical diagrams, and equipment certifications. Processing times vary widely by utility — from a few days to several months. Some utilities charge interconnection application fees ($50–$500), while others process them for free. The agreement must be approved before your system can be legally connected to the grid and begin operating. In some cases, utilities may require system upgrades (like a new transformer) if the local grid cannot support additional solar capacity, which can delay the process. The interconnection agreement is separate from, but related to, the Permission to Operate (PTO) that formally activates your system.