Grid

Smart grid transitions are reconfiguring grid architecture at multiple levels. At the transmission level, new interconnectors and grid-forming inverters are changing how system inertia and frequency regulation work. At the distribution level, the proliferation of rooftop solar, batteries, and electric vehicles is turning networks designed for one-way power flow into active systems with bidirectional flows. The concept of the grid is expanding to include communication infrastructure, data platforms, and logical coordination layers alongside the physical wires and transformers.

The grid encompasses the physical infrastructure of electricity transmission and distribution — lines, cables, transformers, substations, and switching equipment — together with the communication systems, control architectures, and logical coordination functions that manage power flows across it. In the context of smart grid transitions, “grid” is often used to denote the full socio-technical system: not just the wires, but also the standards, ownership arrangements, operational rules, and data flows that determine how the physical network behaves.

A useful distinction separates the transmission system — high-voltage, long-distance, interconnected at national or regional scale — from the distribution system — medium and low voltage, reaching end-users, historically passive and radial in design. Smart grid development is most pronounced at the distribution level, where new actors, devices, and services are creating coordination challenges the original architecture was not designed for.

Several reference frameworks have been developed to describe smart grid architecture systematically, supporting interoperability planning, standards development, and the design of new grid services. Three frameworks are in widespread use internationally.

The SGIRM, originally developed in IEEE Std 2030-2011 and updated in IEEE 2030.4-2023, organises smart grid architecture around three integrated architectural perspectives (IAPs) and three physical domains.¹⁾

The three IAPs cover, respectively: components and functions (physical assets including generation, storage, loads, and transmission and distribution infrastructure, together with their built-in control functions); information and communications (data models and communication systems supporting asset control, protection, and intelligent functions); and business and economics (market structures, fleet management, aggregation platforms, grid services transactions, tariffs, and regulatory and environmental considerations). The business and economics perspective was added in the 2023 revision to reflect the growing role of distributed energy resources (DER) and market-based coordination.

The three physical domains are: generation, storage and DER; transmission and distribution; and load/end-use (including EV charging, demand response, and HVAC). Three physical location zones cut across these domains: grid-edge (load/customer end), field/substation, and enterprise/cloud.

The GridWise Architecture Council's Transactive Energy Framework provides a conceptual architecture for designing systems that use economic and control techniques together to improve grid reliability and efficiency.²⁾

The GWAC Stack organises interoperability across three broad groupings: technical (basic connectivity, network interoperability, syntactic interoperability); informational (semantic understanding, business context, business procedures); and organisational (business objectives, economic/regulatory policy). Transactive energy spans all three groupings, linking physical and cyber infrastructure at the lower levels with business models, market structures, and regulation at the upper levels. A conceptual architecture defines the abstract components and their relationships; logical and physical architectures specify how those components are structured and instantiated.

The SGAM, developed by the CEN-CENELEC-ETSI Smart Grid Coordination Group and adopted as the reference architecture for EU smart grid standardisation, represents grid architecture as a three-dimensional model.³⁾

The three axes are: Domains (the physical energy conversion chain: generation, transmission, distribution, DER, customer premises); Zones (operational hierarchy from process to field, station, operation, enterprise, and market); and Interoperability Layers (component, communication, information, function, and business). Use cases are mapped into this three-dimensional space, making explicit which domains, zones, and layers a given smart grid function involves and where interoperability requirements arise.

Beyond technical architecture, the configuration of a grid network has governance implications. A WG7 analytical framework developed by Klaus Kubeczko maps the relationship between network architecture (the hardware, software, orgware, and spatial configuration of the network) and two further dimensions: the logical layer (algorithms and ledger systems), and the policy layer (decision power over the rules of the system).⁴⁾

The resulting cross-tabulations — network architecture against logical configuration, and network architecture against governance/policy configuration — reveal how different combinations produce structurally distinct grid types, from centralised national monopolies to distributed locally co-owned grids.

Network architecture and logical layer

Network architecture and policy layer

; Transmission system : High-voltage, long-distance network connecting large generation sources and bulk consumers across national or regional geographies. ; Distribution system : Medium and low-voltage network delivering electricity to end-users; historically radial and passive, increasingly active with distributed generation and flexible loads. ; Domain : In SGAM, a segment of the physical energy conversion chain (generation, transmission, distribution, DER, customer premises). ; Zone : In SGAM, a level of the operational hierarchy, from physical process to enterprise and market. ; Interoperability layer : In SGAM, one of five levels at which components, systems, or organisations must be able to exchange meaningful information: component, communication, information, function, or business. ; Transactive energy : A control and coordination approach combining economic signals with physical control to balance supply, demand, and network constraints across distributed grid actors. ; Grid-edge : Devices and systems at the load/customer end of the distribution network, including smart meters, inverters, EV chargers, and building energy management systems.

Grid and network. “Grid” in the electricity sector typically refers to the physical infrastructure of lines, cables, and transformers, together with its control and communication overlay. “Network” is used both in this technical sense and more broadly to describe actor-networks, communication networks, or logical coordination structures. The two overlap substantially in smart grid discourse, where the physical grid and its digital overlay are increasingly inseparable.

Grid architecture and grid operation. Architectural frameworks such as SGAM, SGIRM, and GWAC describe the structural composition of the grid, the layers it contains, and the interfaces between them. Grid operation — frequency regulation, voltage control, balancing, ancillary services — concerns how that structure performs in real time. The two are related but distinct: architectural choices constrain and enable operational possibilities, but operational functions are treated separately in the Operability topic.

Centralised, decentralised, and distributed. These terms describe both physical network topology and governance logic. A centralised physical network is not the same as centralised governance, and combinations of the two produce structurally distinct system types with different implications for ownership, participation, and resilience. See Decentralisation.

Infrastructure, Digitalisation, Decentralisation, Grid Edge, Grid Ownership, Systems, Energy Logistics, Service

CEN-CENELEC-ETSI Smart Grid Coordination Group. Smart Grid Architecture Model (SGAM) Framework. https://digital-strategy.ec.europa.eu/en/policies/eu-policy-digitalisation-energy

Farhangi, H. (2010). The path of the smart grid. IEEE Power and Energy Magazine, 8(1), 18–28. https://doi.org/10.1109/MPE.2009.934876

GWAC (2019). GridWise Transactive Energy Framework, Version 1.1. GridWise Architecture Council. https://gridwiseac.org/pdfs/pnnl_22946_gwac_te_framework_july_2019_v1_1.pdf

IEEE (2023). 2030.4-2023 — IEEE Guide for Control and Automation Installations Applied to the Electric Power Infrastructure. IEEE.

Kubeczko, K. (2017). Die Rolle von Smart Grids in der Transition zu nachhaltigen Energiesystemen. Keynote, IEA Vernetzungstreffen, Salzburg, 12 October 2017.

NIST (2021). Framework and Roadmap for Smart Grid Interoperability Standards, Release 4.0. National Institute of Standards and Technology. https://www.nist.gov/ctl/smart-connected-systems-division/smart-grid-group/smart-grid-framework