Telecom carriers need to reduce operational expenditures (OPEX) to reduce total network cost. Such OPEX include power consumption, maintenance, and repair related costs, all of which must be considered, especially when providing various network services nationwide. This paper thus presents the Photonic Sub-Lambda transport network (PSL network), an energy-efficient and reliable optical network architecture for metro networks. Numerical results reveal that the PSL network can simultaneously reduce power consumption by 30%+, failure-recovery operations by 40%+, and repair costs by 80%+ compared with reconfigurable optical add/drop multiplexer (ROADM)-based networks.