This document discusses innovative concepts for improving metro rail energy efficiency and sustainability, including the use of permanent magnetic synchronous motor (PMSM) technology. It provides: 1) An overview of PMSM technology and its benefits of reducing power consumption, noise pollution, and maintenance requirements compared to traditional metro motors. 2) A case study of SMRT's assessment of PMSM technology, including simulation results showing over 30% energy savings and 12dB noise reduction, as well as plans to equip 85 trains with PMSMs by 2020. 3) Information on how metros can become more environmentally friendly through the use of efficient technologies like PMSMs.