In a grid connected PV system, also known as a “grid-tied”, or “on-grid” solar system, the PV solar panels or array are electrically connected or “tied” to the local mains electricity grid which feeds electrical energy back into the grid. Before connecting a solar panel, you need to understand how it works and plan properly. There are several ways to connect the panels (series, parallel, mixed) and the choice depends. Grid-tied systems dominate 2025 residential solar: With 90% of installations being grid-tied, these systems offer the best ROI at $2. Professional installation is essential for. Professional Installation is Critical: Grid-tied solar systems require licensed electricians and multiple permits, with the interconnection process typically taking 2-8 weeks and costing $200-$2,000 in fees alone.