Background
Insulator pollution emerged as a significant network reliability issue during the 2024/25 summer period, impacting areas including the Yorke Peninsula, Kangaroo Island, the West Coast and the Limestone Coast. At the time, it was considered an infrequent issue linked to specific weather conditions.
However, with similar impacts beginning to emerge again in subsequent years, SA Power Networks is pivoting its approach with the decision to establish a dedicated taskforce to deal with the issue of insulator pollution.
What is insulator pollution?
Insulators are essential components of the power grid that support and isolate electrical conductors. They are designed to prevent the flow of electricity to ground. However, over time during prolonged dry periods without washing rains, insulators can become coated with dirt, salt, or other contaminants. This build-up of material can create a conductive path along the surface of the insulator. When combined with moisture such as dew or high humidity, this build-up can reduce the insulating capability of the equipment, allowing electricity to track across the surface and trigger outages.
Insulator pollution is not caused by asset failure or lack of maintenance, but is a weather-driven, system-wide challenge that can affect many assets at once.
How insulator pollution causes power outages
When insulators become polluted, they can experience a phenomenon called a flashover. This occurs when the electrical current arcs across the surface of the polluted insulator, causing a short circuit. This can lead to power outages, either momentarily or for longer periods.
Video - Insulator pollution explained
Types of power outages caused by insulator pollution
Momentary outages
Momentary outages are very short interruptions in your electricity supply, typically lasting only a few seconds. They occur when there are intermittent or short duration electrical faults.
Prolonged outages
Unlike momentary outages, prolonged outages indicate a more substantial fault within the power grid. These events can stem from various causes, including severe weather damage to infrastructure, equipment failures, or extensive insulator pollution that overwhelms protective mechanisms.
When a significant fault occurs, our systems may require manual intervention to identify and repair the problem and restore power. This process can involve detailed inspections, repairs, and careful switching operations, all of which contribute to the extended duration of the outage. Our teams work diligently to identify and resolve the root cause and restore power as quickly and safely as possible, prioritising the safety of both our crews and the public.
Mitigating the effects of insulator pollution
Insulator pollution is not caused by asset failure or lack of maintenance. It is a weather-driven, system-wide challenge that can affect many assets at once. We take several steps to mitigate the effects of insulator pollution:
- Cleaning techniques: We employ various cleaning techniques to remove contaminants from insulators, such as washing with deionized water.
- Regular inspections: We regularly inspect our powerlines and equipment to identify and address any signs of insulator pollution.
- Insulator designs: We use the highest quality insulators that naturally offer some resistance to pollution.
Picture: SA Power Networks' crews wash insulators to remove insulator pollution.
Due to the vast number of insulators across our network, it is not physically possible to clean them all. Significant rainfall is ultimately necessary to fully resolve and manage the issue of insulator pollution.
Factors that contribute to insulator pollution
Several factors can contribute to insulator pollution, including:
- Weather patterns: Prolonged dry periods can lead to the accumulation of dust and dirt on insulators.
- Environmental conditions: High humidity, salt spray from coastal areas, and industrial emissions can contribute to the deposition of contaminants on insulators.
- Proximity to industrial areas: Industrial emissions can contain particles that can settle on insulators and contribute to pollution.
Our commitment to reliability
We are committed to providing a safe, reliable power supply to our customers.
Following the re-emergence of insulator pollution across parts of regional South Australia, we have established a dedicated multi-disciplinary taskforce to strengthen our response to the issue. The taskforce brings together operational, engineering and customer teams and is focused on two priorities — responding effectively when insulator pollution causes outages, and reducing the likelihood of outages occurring in the future.
Practical actions being taken include:
- Increasing crew availability during high-risk periods and in affected regions, including additional internal resources and external contractors.
- Targeted inspections of powerlines and insulators to identify assets most at risk and prioritise them for action.
- Insulator washing and replacement programs, particularly in areas where extended dry conditions mean natural 'washing rains' have not occurred.
- Engaging expert advice to better understand why the issue has resurfaced and inform longer-term asset management strategies.
- Considering network configuration options where possible to reduce customer impacts if faults occur.
By understanding and addressing the issue of insulator pollution, we can help to minimise the frequency and duration of power outages.