There are certain panel box requirements to go solar. The panel box is the mediator between a homeowner’s connection from the utility and their devices. Generally, for a residential connection, service wires from a transformer supply electricity to the energy meter where the incoming electricity is calculated and the customer is billed accordingly. From here, these wires go to the panel box.
The panel box has two busbars rated for 120 V each and a current carrying capacity equal to the service connection. The incoming wires supply power to two busbars inside the panel and these in turn supply power to all the household devices through breakers present on these busbars.
The panel box matters while installing a solar photovoltaic system because in a typical load side connection, the output of a solar PV system through the inverter is connected to this panel box. It is connected through a breaker rated with an NEC mandated amperage to the busbars inside the panel.
In some cases, in order to accommodate the new breaker required by the solar system, there needs to be changes to the panel box – the worst case scenario being a service upgrade, which involves increasing the service connection from maybe a 100 A system to a 200 A system. This may be expensive, but there are ways of avoiding an upgrade, like derating the main breaker, tapping onto the supply side, etc. So, while there are panel box requirements to go solar, there are also workarounds to save you as much as possible.