1540-7977/17©2017IEEE 74 IEEE power & energy magazine may/june 2017 I IN ADDITION TO THEIR AGE, PARTICULARLY IN large metropolitan areas, electric power systems through- out the industrialized world face challenges brought on by new technology trends, environmental concerns, evolving weather patterns, a multiplicity of consumer needs, and regulatory requirements. New technology trends include the development of more efficient, reliable, and cost-effec- tive renewable generation and distributed energy resources (DERs), energy storage technologies, and electric vehicles (EVs), along with monitoring, protection, automation, and control devices and communications that offer significant opportunities for realizing a sustainable energy future. The medium- to long-term vision for the electrical grid is to transition away from carbon-based fuels toward increased penetration of renewable DERs and use of energy storage and electric transportation. In the past, the transmission and distribution (T&D) system was designed and built to serve peak demand (and comply with reliability and quality of service requirements); it was a passive delivery infrastructure with a radial “down- and-out” paradigm for delivering energy to consumers. Con- sumers used what they needed or wanted, the wholesale infrastructure provided the energy, and the T&D system pro- vided it with no need for real-time operation. Distribution operations consisted of construction, maintenance, and out- age management—not of managing delivery per se. Today, customers increasingly use the grid as a means to balance their own generation and demand and as a sup- plier of last resource when their own generation is unavail- able. They expect to deliver excess generation back to the By Julio Romero Aguero, Erik Takayesu, Damir Novosel, and Ralph Masiello Digital Object Identifier 10.1109/MPE.2017.2660819 Date of publication: 19 April 2017 Modernizing the Grid