In the energy sector, maintenance plays a crucial role in ensuring a sustainable and reliable power supply. Disruptions in power grids, power plants, or substations can have significant consequences for both society and the economy. Therefore, selecting the right maintenance strategy is critical to ensuring stable supply and minimising the risk of outages.

This article provides an overview of the four main maintenance methods – reactive, preventive, condition-based, and predictive – and how they can be applied to address the unique challenges of the energy sector.

Reactive Maintenance

Reactive maintenance is a maintenance strategy where actions are taken only after a fault or failure has occurred. This type of maintenance focuses on addressing problems as they arise, rather than trying to prevent them in advance. It is also referred to as "corrective maintenance" as it involves restoring or repairing equipment to operational condition after a breakdown.

How it works: Reactive maintenance involves personnel responding to urgent issues by inspecting and repairing equipment that has stopped functioning. Repairs are carried out only after a fault occurs and operations are impacted, which can sometimes result in extended downtime.

Example: If a transformer at a substation fails unexpectedly, technicians are dispatched to identify the cause and carry out the necessary repairs or replacements to restore the system.

Key focus: Actions are taken only after a fault or failure, meaning the maintenance is unplanned or unforeseen. Reactive maintenance increases the risk of costly repairs and longer, more expensive downtimes when a fault occurs.

Preventive Maintenance

Preventive maintenance is a strategy where inspections, repairs, and replacements are performed at predetermined intervals or after a set period, regardless of whether the equipment shows signs of deterioration. The goal is to prevent faults from occurring through regular actions.

How it works: Preventive maintenance is based on scheduled maintenance activities, such as replacing components after a certain period of operation or performing regular inspections and cleanings.

Example: Replacing transformer oil every 12 months, regardless of its actual condition.

Key focus: Preventive actions are carried out based on time or usage, rather than current data on the equipment’s condition.

Condition-Based Maintenance, CBM

Condition-based maintenance is a strategy where maintenance is performed when the actual condition of the equipment indicates signs of deterioration. The decision to perform maintenance is based on continuous or periodic monitoring of the equipment using sensors and measuring instruments.

How it works: Sensors monitor the condition of machines in real time (e.g., vibrations, temperature), and maintenance is performed only when the measurements indicate it is necessary.

Example: If a transformer starts showing higher-than-normal temperatures, the system sends a warning, allowing preventive actions to be taken before a fault occurs.

Key focus: Actions are taken when specific condition parameters exceed normal levels or thresholds.

Predictive Maintenance, PdM

Predictive maintenance focuses on forecasting when equipment will require maintenance by using advanced analytics and technologies such as AI and machine learning. It relies on real-time data from sensors but emphasises predicting future failures before they occur.

How it works: Predictive maintenance uses historical and real-time data from sensors, combined with AI models and data analysis, to predict when a fault is likely to occur. Maintenance is carried out before the expected failure happens.

Example: An AI system can analyse vibration data from a motor and, based on past patterns, predict that the motor will fail within two months if no action is taken.

Key focus: Utilising analytics and forecasts to identify when maintenance is needed before a problem arises.

Conclusion

As the energy sector’s demands for reliability and efficiency grow, choosing the right maintenance strategy becomes increasingly important. By combining modern technology with a strategic approach to maintenance, players in the energy sector can not only reduce disruptions but also meet society’s growing energy needs in a sustainable way.

Whether it involves addressing faults quickly, preventing them through regular inspections, monitoring equipment health in real time, or using AI to predict future issues, the right strategy can strengthen the energy system’s resilience and contribute to a more secure and stable energy supply.