Load Center / Subpanel

A load center, commonly called a subpanel, is a secondary electrical distribution panel that receives power from the main service panel and distributes it to a specific group of circuits. In solar installations, subpanels are used when the main panel lacks space for a solar breaker or when specific circuits need to be isolated.

In battery-backed solar systems, a subpanel (often called a critical loads panel or backup panel) is used to separate the circuits you want powered during a grid outage from the rest of your home. Only the circuits wired to this subpanel will receive backup power from the battery. This approach is more practical and cost-effective than trying to back up the entire home, which would require a much larger (and more expensive) battery system. Common circuits moved to the critical loads subpanel include the refrigerator, select lights, internet router, phone chargers, and medical equipment. Your solar installer will work with you to decide which circuits are most important to keep running during an outage.