Chaudhuri, BalarkoBalarkoChaudhuriRamasubramanian, DeepakDeepakRamasubramanianMatevosyan, JuliaJuliaMatevosyanO’Malley, MarkMarkO’MalleyMiller, NickNickMillerGreen, TimTimGreenZhou, XiaoyaoXiaoyaoZhou2024-01-262024-03IEEE Power and Energy Magazine, 2024, 22 (2), pp.30-411540-7977http://hdl.handle.net/10044/1/108878The primary objective of electricity grids is to reliably meet the electricity demand at a minimum cost. This objective can be broken down into a set of needs that are met through services. These services are procured by mandating them either in grid codes or via market mechanisms. While grids in different countries/regions share common features in terms of needs and services, there are variations arising in physical, regulatory, and policy contexts. With the increased use of inverter-based resources (IBRs), such as wind and solar photovoltaic (PV) power and battery energy storage systems (BESSs), grids are undergoing changes that are altering the balance between needs and services. This balance is crucial in managing changes that will ensure that grids will continue to be able to meet demands. As increasingly more synchronous machines (SMs) are replaced by IBRs, the services inherently provided by the remaining SMs are dwindling, thus requiring the IBRs to contribute where they can.Copyright © 2024 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.Journal Articlehttps://www.dx.doi.org/10.1109/mpe.2023.3342113http://dx.doi.org/10.1109/mpe.2023.33421131558-4216