Over many decades, the centralized power grid — a one-way flow of electricity, generated by large, remote power plants and distributed over miles of transmission lines to homes and businesses — succeeded in delivering electricity across continents to billions. But in recent years the system’s shortcomings have become increasingly evident. The conventional grid is largely dependent on planet-warming fossil fuels. And because it’s so big and interconnected, it’s vulnerable to massive disruption by natural disasters and susceptible to physical or cyberattack