def min_duration_rule(mod, g, p):
    """
    **Constraint Name**: StorNewLin_Min_Duration_Constraint
    **Enforced Over**: STOR_NEW_LIN_OPR_PRDS

    Storage duration must be above a pre-specified requirement in each
    operational period.
    """
    return mod.StorNewLin_Energy_Capacity_MWh[g, p] \
        >= mod.StorNewLin_Power_Capacity_MW[g, p] \
        * mod.stor_new_lin_min_duration_hrs[g]