If we refer to energy flow in a PV system, the next component of an off grid PV system is the controller.

PWM and MPPT are the most used types of controllers. If you decide to work with a PWM, voltage and current are the selection parameters. Whereas, voltage refers to array's Voc and current refers to array's Isc. Controllers comes as single units or inbuilt in the inverter.

If using a MPPT, the array output power and the system voltage must be within the range of the controller.

MPPT solar charge controllers allow using high wattage off-grid systems. They are selected based on the combination of wattage and battery voltages.

Storage batteries charging current should also be considered when selecting a MPPT.

Electrical standards request to oversize the controller. Mostly, a 125% over sizing factor for current input and 120% for voltage.