Equation 9-3
kWhbatt = kWPVdc x B / D0.5
WHERE:
kWhbatt = Rated Useable Energy Capacity of the battery storage system in kWh
kWPVdc = PV system capacity required by section 9.2 in kWdc
B = Battery energy capacity factor specified in Table 9.6 for the building type
D = Rated single charge-discharge cycle AC to AC (round-trip) efficiency of the battery storage system