A grid-tied solar system connects directly to the utility grid without a battery backup, allowing homeowners to export excess solar generation and import power when needed. These systems represent over 95 percent of residential solar installations in the United States because of lower costs and higher efficiency compared to battery-based systems. Grid-tied systems typically include solar panels, an inverter, and interconnection equipment meeting utility and electrical code requirements.
Operation and Benefits
During sunny periods, grid-tied systems generate power for household use and export surplus electricity to the grid through a bidirectional meter. This net metering arrangement credits customers at avoided cost rates, typically $0.08 to $0.15 per kilowatt-hour. At night or during cloudy weather, customers draw power from the grid at standard retail rates. The grid effectively acts as a free battery, eliminating the $8,000 to $15,000 battery cost.
Interconnection Requirements
Grid-tied systems must meet IEEE 1547 interconnection standards and utility-specific requirements. Inverters must automatically disconnect during grid outages, preventing energized power lines that could injure utility workers. Certified installers complete interconnection agreements and pass third-party inspections before systems can export to the grid. Annual monitoring ensures continued code compliance and safe operation.