Extending transformer life for sustainable grids

Why online condition monitoring matters

As the energy transition accelerates, power grids face unprecedented challenges. Electrification of transport and heating, and the fast rise of data centers are sharply increasing electricity consumption – projected to even double during the next 25 years. 

Modern data centers, powered by AI and cloud services, can each draw as much power as a small town, adding constant, high load to already stressed grids which have been under increased dynamic loading due to rapid growth in renewables, and expansion of distributed generation.

Yet these growing demands arrive at a time when transformer fleets across many regions are ageing faster than new capacity is built. The global supply chain for new transformers is strained, with delivery times now commonly 18 to 36 months. 

Utilities are left managing a capacity gap: ageing assets, more dynamic and heavier loading, and replacement equipment that may take years to arrive. In this environment, extending transformer life becomes both a reliability necessity and a sustainability opportunity.

Ageing infrastructure meets a more demanding grid

Transformers built decades ago for stable, predictable loading now face far more complex operating conditions. Renewable generation introduces fluctuating power flows; distributed energy resources cause irregular load patterns; electrified transport increases peak demand; and data centers add large, continuous, and often rapidly expanding load requirements.

These combined pressures accelerate insulation ageing, increase thermal stress, and heighten the risk of faults—especially in older units. Traditional time-based maintenance simply cannot keep pace with this new reality. What utilities need is continuous visibility into transformer health.

Life extension through real-time condition monitoring

Online condition monitoring – particularly Dissolved Gas Analysis (DGA) – is one of the most effective tools for condition assessment enabling transformer life extension. 

Continuously measuring gases in transformer oil to detect early signs of hotspots, thermal stress, partial discharges, and incipient faults makes a DGA monitor essentially into a real-time health monitor that often reveals issues long before they become critical.

Closing the capacity gap through refurbishment and rerating

With long lead times for new transformers, as additional tools in capacity management utilities can evaluate their option for transformer refurbishment and rerating.

Refurbishment, which may include insulation drying, oil reclamation, sealing system repairs, modification of preservation system, bushing upgrades, increasing cooling capacity, or sometimes even rewinding – can return ageing transformers to even near-new condition. This approach is faster, significantly more sustainable, and far less resource-intensive than always purchasing new equipment.

Rerating, or safely increasing a transformer’s loading capability, helps utilities meet growing demand from electrification and data centers. But rerating must be guided by real-time condition data. Monitoring – especially DGA, moisture tracking, and thermal modelling – may give operators the option to safely release hidden capacity without shortening asset life.

A sustainable path forward

Transformers sit at the heart of the clean energy transition. Extending their life with online condition monitoring is one of the most impactful steps utilities can take to support rising demand from electrification, renewable integration, and data center expansion. Each additional year of operation reduces material use, lowers emissions, and strengthens grid resilience.

As electricity consumption continues to surge, smarter asset management becomes essential – not optional. Online monitoring equips utilities with the insight needed to operate ageing transformer fleets safely, sustainably, and reliably for decades to come.