Seeing the Whole Grid: Rethinking Transformer Monitoring in a Complex World

Transformer failures are costly, yet fleet-wide health visibility remains a major challenge. We talked to Hans Rigole, Expert Condition Monitoring of transformers at ENGIE Laborelec. His session at Asset Performance 2025 reveals how OneBoard brings clarity, foresight and structure to transformer asset management.

The Visibility Gap in Transformer Asset Management

In energy-intensive industries and grid networks, power transformers are critical components. Their condition directly impacts uptime, operational safety and long-term infrastructure planning. Yet as fleets grow and assets age, maintaining a clear overview of transformer health remains a challenge.

Hans Rigole, expert in transformer diagnostics at ENGIE Laborelec, observes this across many organisations. “We work with asset owners managing ten to over a thousand transformers,” he explains. “In many cases, they rely on fragmented sources, PDFs, spreadsheets, isolated reports. That makes fleet-wide insights difficult to obtain.”

Monitoring typically depends on periodic oil sampling, followed by lab-based reporting. While effective for individual units, this process doesn’t scale easily. Spotting trends, comparing results or prioritising interventions across dozens — or hundreds — of assets becomes time-intensive and reactive. “Some teams set aside full days each year just to review reports,” Hans says. The result can be missed degradation signals and reduced ability to act ahead of failure—especially in ageing assets.

New Pressures on Ageing Assets

This lack of visibility is increasingly problematic under current conditions. Procurement timelines for new transformers now stretch to two or three years, and prices have risen sharply. Meanwhile, the energy transition is placing new demands on ageing infrastructure. “Many existing transformers will be running hotter and longer than they were designed for,” Hans explains. “That accelerates aging, especially of the insulation system, and increases the risk of unplanned failure.”

Another barrier to effective decision-making is internal fragmentation. In larger organisations, health data is often scattered between maintenance, engineering, and operations teams—or even between regional entities. “In some cases, no one can tell how a transformer’s condition has changed over time,” Hans explains. “Without trends, you can’t act proactively.”

Improving Oversight with Digital Tools

To address this, ENGIE Laborelec developed a digital platform that consolidates transformer condition data into one accessible system. The platform, used in combination with standard oil analyses, enables teams to assess both individual asset status and overall fleet condition.

“Instead of static reports, users can explore health data in an interactive dashboard called OneBoard,” Hans says.You can view individual asset health or zoom out to assess the status of your entire fleet.” The system flags anomalies, supports trend analysis, and provides intuitive visual indicators that make it clear where attention is needed.

The tool can be accessed via browser across teams and sites. “We wanted to give asset managers and engineers a shared, structured view,” Hans adds. “It’s structured, searchable, and always up to date. That makes it much easier to coordinate actions and maintain oversight, and that’s key when decisions are distributed across teams or locations.”

Advanced Monitoring: Predicting Risk and Lifespan

Building on this foundation, ENGIE Laborelec added advanced analytical capabilities to the OneBoard platform. These include a Residual Life Assessment (RLA) model and a Transformer Health Index, both designed to support longer-term planning.

The RLA provides an estimate of remaining service life, based primarily on insulation paper degradation and transformer age. “Once the paper reaches a critical threshold, the unit cannot be restored,” Hans explains. “So it’s essential to anticipate when replacement might be needed. We’ve developed a logarithmic model that uses lab data and historical records to predict remaining lifespan in years.”
This functionality is especially valuable now, with long replacement lead times and high capital costs. By identifying units with less than 5 or 10 years of expected life, asset managers can prepare replacements in time, avoiding catastrophic failure or prolonged outages.

In parallel, the Health Index evaluates the health overview of the fleet using seventeen diagnostic parameters, including dissolved gas levels (DGA), furan and methanol content, water concentration, dielectric breakdown voltage, historical maintenance records and electrical measurements. This as well for the main tank, OLTC, cable boxes and bushings. Based on real subject-matter expert interpretation, OneBoard ranks each asset and presents a fleet-wide risk map, enabling risk-based maintenance and investment planning.

“Some organisations apply this only to a subset of critical assets,” Hans says. “For example, an industrial user of OneBoard monitors over 100 transformers. They selected 10 to 15 units for enhanced follow-up using these tools.”

Aligning People, Sites and Systems

For many asset owners, the bigger challenge isn’t the technical data, it’s aligning people and processes. Hans recounts a recent experience with a Belgian asset owner whose sites in Flanders and Wallonia had entirely separate monitoring practices. “Reports were generated, printed, and stored locally. No one was tracking whether conditions were improving or worsening,” he says. “Reports were stored locally or lost between teams,” he says. “If an anomaly appeared, there was no trend to compare it to. That makes decision-making harder.”

The use of a shared monitoring platform such as OneBoard helps bridge these gaps. Authorized users from various functions in maintenance, asset management, engineering can access the same data set. Mobile access is also possible via the website “The idea is to make asset health part of everyday awareness, not just an annual review,” says Hans.

For asset owners with online monitoring systems already installed on transformers – such as real-time DGA sensors – OneBoard can also integrate live data streams. This supports continuous supervision, automated alarms, and faster incident response. “It only works if you actually follow up on the alerts,” Hans adds with a smile, “but the platform is fully ready to support that workflow.”

Live Demonstration at Asset Performance 2025

At the upcoming Asset Performance conference, ENGIE Laborelec will present a live demo of the platform, with special attention to the Residual Life and Health Index functionalities. The session will also cover practical cases of how transformer monitoring is evolving—from periodic inspection toward data-driven asset management.

Hans sees it as an opportunity to exchange ideas. “We’re not just showcasing a tool,” he says. “We want to explore how organisations can make better use of the data they already have—and structure it in a way that supports strategic planning.”

Hans puts it plainly: “If you’re an asset manager responsible for a medium to large transformer fleet, this session is for you. OneBoard is here to make your life easier.” Whether you’re facing fragmented data, ageing assets, or a growing sense of uncertainty around transformer condition, this presentation offers a compelling solution. OneBoard brings clarity, efficiency, and foresight to transformer fleet management. Exactly what technical leaders need to meet the challenges of tomorrow.