On-Grid vs. Off-Grid Solar
Grid-tied systems connect to the utility and use net metering; off-grid systems are entirely self-sufficient with batteries — most residential installations are grid-tied.
Grid-tied (on-grid) solar systems connect to the utility electricity grid and lack battery storage by default. They rely on net metering to credit excess production and draw from the grid when panels under-produce. Grid-tied systems are less expensive (no batteries), simpler, and more financially efficient where net metering policies are favorable. Limitation: they shut down during grid outages by design (to prevent backfeed that could endanger utility workers).
Grid-tied with battery backup adds storage that powers critical loads during outages while maintaining grid connection. This is increasingly popular but adds $10,000–$20,000 to system cost.
Off-grid systems are entirely disconnected from the utility — all power comes from solar plus battery storage. They require substantially larger battery banks (to handle multiple cloudy days), generator backup, and careful load management. Off-grid costs are typically 2–3× higher than grid-tied equivalent for the same daily energy needs. Off-grid is primarily appropriate for rural properties where utility connection costs exceed $15,000–$30,000, or for deliberate energy independence.
Real-World Example
The rural property was 800 feet from the nearest utility pole; the electric cooperative quoted $28,000 for connection — making a $45,000 off-grid solar-plus-battery system competitive on first cost while delivering permanent energy independence.