October 2026

Retrofit and compact solutions: two complementary approaches to low-voltage grid digitalisation

Electrification, distributed generation and the growing adoption of electric vehicles are increasing the variability of power flows across low-voltage networks. For utilities, this makes granular information on loads, imbalances and feeder behaviour increasingly important.

The digitalisation of electrical networks enables measurement, monitoring and communication capabilities to be incorporated into secondary stations, but not every installation requires the same strategy. The condition of existing assets, the low-voltage panel architecture, installation constraints and the required level of monitoring all influence the most suitable approach.

In this context, retrofit solutions and compact solutions represent two complementary ways of progressing towards smarter grids.

Retrofit: digitalising existing infrastructure

Retrofit solutions make it possible to add new grid monitoring capabilities to existing infrastructure, reducing the need to replace assets that remain fully operational.

Within the Zillion ecosystem, the LRG | Feeder Retrofit Rogowski is designed for this type of deployment. Current measurement is performed using Rogowski sensors, enabling integration around existing conductors with minimal mechanical intervention.

The solution can also be installed without de-energising the installation, avoiding supply interruptions and reducing the operational impact of deployment.

This approach is particularly suitable when:

the existing low-voltage panel remains operational
measurement needs to be added to existing feeders
continuity of supply must be maintained during installation
digitalisation is being deployed progressively across secondary stations, feeders or network areas
different configurations coexist within the same network

Retrofit solutions therefore make it possible to increase the level of supervision without necessarily replacing existing assets, while supporting scalable deployments across a large installed base.

Compact solutions: integrating more functions from the outset

For new installations or low-voltage panels undergoing renewal, it can be more effective to integrate digitalisation capabilities directly into the equipment design.

The SFS | Smart Fuse Switch Base follows this approach by integrating protection and sensing directly into the fuse switch base.

The SFS captures current by feeder and phase, together with the voltages associated with each feeder. These signals are processed by the TSA | Line Feeder Meter from Merytronic, which obtains the three-phase electrical parameters required to characterise feeder behaviour.

These include:

voltage and current
active, reactive and apparent power
power factor
frequency
imported and exported energy
RMS values

This architecture turns each low-voltage feeder into a measurement point integrated within the protection system itself, providing relevant information for grid monitoring, diagnostics and operation.

This approach can be particularly valuable when:

a new low-voltage panel is being designed
an existing installation is being renewed
a more compact and streamlined solution is required in terms of space and wiring

Two approaches, one strategy

Retrofit	Compact
Installed on existing assets	Integrated into the equipment design
Can be deployed without de-energising	Integrates protection and sensing
Supports a phased evolution	Simplifies the architecture of new installations

There is no need to apply a single model across the entire network. A utility may use retrofit solutions in existing secondary stations while deploying compact solutions in new installations or refurbishment projects.

The decision will depend on the condition of the assets, installation constraints and the objectives of the digitalisation project.

The ability to combine technologies is one of the principles behind Zillion, Alive and Smart Grids by Gorlan: a modular and scalable architecture designed to integrate existing infrastructure and enable progressive digitalisation.

A grid architecture designed to evolve

This combination of approaches reflects the Zillion philosophy: a modular and scalable architecture that enables the progressive digitalisation of low-voltage networks while adapting to different grid configurations.

Sensing is only one layer of this architecture. Measurement, communications and future grid automation capabilities must be able to evolve in a coordinated way and integrate with utilities’ IT/OT systems.

Moving towards Smart Grids does not mean applying a single solution across the entire network. It means selecting the most appropriate architecture for each asset while ensuring that every deployment can become part of a common digitalisation strategy.

Learn more about Zillion ecosystem