Feature Article: Smart Grid Toward a Secure and Resilient All-Renewable Energy Grid for Smart Cities Charalambos Konstantinou Florida State University Abstract-The concept of smart cities is driven by the need to enhance citizens' quality of life. It is estimated that 70% of the world population will live in urban areas by 2050. The electric grid is the energy backbone of smart city deployments.An electric energy system immune to adverse events, both cyber and physical risks, and able to support the integration of renewable sources will drive a transformational development approach for future smart cities. This article describes how the future electric energy system with 100% electricity supply from renewable energy sources requires the " birth of security and resiliency " incorporated with its ecosystem. & ELECTRIC ENERGY SYSTEMS constitute the backbone of critical infrastructure. National security and economic vitality rely on a safe, secure, and resilient power system. The American electric grid, once considered a marvel of 20th century engineering, has become obsolete in the face of 21st century threats. Our energy grid has Digital Object Identifier 10.1109/MCE.2021.3055492 Date ofpublication 29 January 2021; date ofcurrent version 6 December 2021. numerous shortcomings and can no longer deliver (cyber) secure and (disaster) resilient electric power to businesses and households, leading to an urgent and enormous threat to our society and economy. Vertical power systems with rigid transmission and distribution systemcontrol hierarchy have failed repeatedly during extreme threats. Recent studies by the Federal Energy Regulatory Commission (FERC) found that knocking out as 9 of the 55 000 power substations could result in U.S. coast-to-coast blackouts lasting 18 months or more.1 For example, the Hurricane Michael January/February 2022 Published by the IEEE Consumer Technology Society 2162-2248 ß 2021 IEEE 33