Modular and repeatable grid infrastructure designs
Modular and repeatable grid infrastructure designs use standardized configurations and prefabricated assemblies to reduce the amount of infrastructure that must be engineered and constructed from scratch for each project. Prefabricated substations are one application: equipment and structures such as switchgear, transformers, protection and control systems, auxiliary systems, control rooms and other building elements can be manufactured or assembled into modules off site, transported to their final location and integrated there. Utilities can develop standardized reference designs that define repeatable layouts, equipment arrangements, interfaces and technical requirements, while adapting elements that depend on local network and site conditions. Factory production can take place in parallel with site preparation and civil works, reducing the volume and duration of on-site construction. It can also move assembly, testing and quality control into more controlled environments. Reusing proven designs across subsequent projects can reduce repeated engineering and make equipment requirements, manufacturing and construction processes more predictable. Site-specific engineering remains necessary where network configuration, voltage requirements, environmental conditions, land constraints or safety and regulatory requirements differ.
Main outcomes of the solution
- Affordability: Reusing standardized designs and shifting assembly to controlled factory environments can reduce repeated engineering, on-site construction and rework across successive projects, supporting more efficient use of capital as networks expand.
- Reliability & Flexibility: Modular designs can accelerate the deployment, replacement or expansion of substations and other network infrastructure needed to connect new generation and demand while maintaining the equipment, protection and control functions required for secure network operation.
- System Resilience: Prefabricated and transportable modules can shorten on-site installation and facilitate faster replacement or restoration of critical grid functions following equipment failure or physical disruption, particularly where pre-engineered designs and compatible modules are available.
Key deployment and scaling factors
- Reference designs should standardize layouts, interfaces and equipment configurations that recur across projects while retaining sufficient flexibility for site-specific network, environmental and safety requirements.
- Modularization should be considered early in project design so that factory fabrication, equipment integration and testing can progress in parallel with site preparation and civil works.
- Equipment dimensions, interfaces and transport requirements need to be designed around the practical constraints of moving prefabricated modules from manufacturing facilities to their final sites.
- Factory assembly requires defined quality assurance and testing procedures so that integrated modules can be verified before shipment and final commissioning on site.
- Repeatable designs deliver greater value when utilities establish a sustained pipeline of similar projects, allowing proven engineering and construction approaches to be reused rather than repeatedly customized.
Case study
State Grid Zhejiang (2025), China
In 2025, State Grid Zhejiang Electric Power completed a fully modular 500 kV substation in Fucun township, Jinhua, Zhejiang province. The Pancun village substation applied a construction method combining prefabricated assembly with intelligent systems. More than 80% of its modular components, including the steel-structured control room and firewalls, were prefabricated off site and assembled at the final location. The substation was completed in 14 months – faster than traditional construction methods – while risks associated with work at height were reduced by 50% and dust pollution was minimized. The facility is in a high-tech industrial cluster containing more than 200 enterprises and over a dozen major industrial projects and is expected to ease local power-supply constraints. According to State Grid Zhejiang Electric Power, the substation is also expected to strengthen the local and city-wide main grid by enhancing the flexibility and resilience of the regional power network.
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