Foreword for the special section on smart grid energy management

ENERGY management system (EMS) is well known as the brain of power grid operation, for real-time monitoring, security assessment, dispatch schedule and system-wide control of power systems. This special section addresses the challenges and opportunities for the development of EMS for smart grids. There are seven papers included here, covering operational issues on almost all the sections of smart grids, i.e. renewable generation (wind/PV), transmission, distribution/ microgrid, demand response, building, and home and electricity markets.