Interconnection
Interconnection is the process of connecting a solar PV system (or any distributed energy resource) to the utility grid. It involves a formal application and review process with the local utility or grid operator to ensure the system meets technical, safety, and reliability requirements before it can export electricity to the grid.
Interconnection is one of the most complex and time-consuming aspects of solar project development, particularly for larger systems. For small residential systems, the process may take a few weeks; for utility-scale projects, formal interconnection studies can take 1–3 years or more in congested grid areas.
Interconnection Process (US)
Residential (< 10 kW): Typically a simplified "fast-track" interconnection with utility review of basic technical specifications, inspection by utility or third party, and installation of net metering meter. Takes 2–8 weeks.
Commercial (10 kW–1 MW): May require a distribution impact study if the system could affect local grid stability. Takes 1–6 months.
Utility-scale (>1 MW): Full interconnection study process through FERC-regulated ISO/RTOs or vertically integrated utilities. Includes feasibility study, system impact study, and facilities study. Active transmission queues in major ISOs (MISO, CAISO, PJM) have backlogs of 2–5+ years.
Interconnection Costs
Costs include application fees, study fees, and any required grid upgrades. For residential: $100–$500. For commercial: $1,000–$50,000+. For utility-scale: $10,000–millions depending on required transmission upgrades.
SolarScope's Site Studio Grid Capacity layer shows utility territory data to help assess where interconnection capacity may be available.