Improving SAIDI and SAIFI: strategies for distribution system operators to achieve excellence

Electricity Distribution System Operators (DSOs) play a vital role in ensuring the reliability and efficiency of power supply to millions of customers worldwide. Two key metrics are used to assess their performance: the System Average Interruption Duration Index (SAIDI) and the System Average Interruption Frequency Index (SAIFI). These indicators measure the average duration and frequency of power interruptions, respectively, providing valuable insights into the reliability of power distribution networks.

• SAIDI = Total Duration of Customer Interruptions / Total Number of Customers Served
• SAIFI = Total Number of Customer Interruptions / Total Number of Customers Served

SAIDI and SAIFI are critical for regulatory compliance, operational efficiency, and customer satisfaction. High values indicate frequent and/or prolonged outages, which can severely impact both economic activity and customer trust. Thus, reducing SAIDI and SAIFI is a top priority for DSOs seeking to improve their service quality and resilience.

Sia has recently produced a benchmark study of DSO performance across multiple countries, including Australia, Canada, USA, France, Netherlands, UK, Saudi Arabia, Qatar and UAE. It reveals significant variability in SAIDI and SAIFI values and several key trends emerge:

• In Europe (France, Belgium, Netherlands, UK): low SAIDI and SAIFI values, largely due to extensive underground cabling and robust regulatory frameworks. For example, Enedis, a major DSO in France, maintains an average annual SAIDI of just 36 minutes per customer, among the best in the world. However, Dutch DSOs report higher SAIDI values than their neighbors, suggesting longer outage durations due to higher proportion of overhead lines still present in the country, especially in rural and semi-urban areas.
• In the Middle East (UAE, Qatar, Saudi Arabia): DSOs DEWA (UAE) and KAHRAMAA (Qatar) have exceptionally low SAIDI and SAIFI values, thanks to modern infrastructure, strong government investment and advanced grid technologies. In contrast, Saudi Arabia shows notable regional disparities among DSOs. Indeed, some perform well while others experience significantly higher outage frequencies and durations, making it one of the less reliable performers overall in the sample.
• North America (US, Canada): significant variability exists. PG&E (active in California) faces high SAIDI values due to wildfire risks, while Hydro Québec (Canada) struggles with long outage durations caused by severe weather. SaskPower in Canada has among the highest SAIFI scores, indicating frequent interruptions.
• Australia: DSOs such as Western Power and Ausgrid have steadily improved SAIDI and SAIFI through infrastructure modernization and microgrid deployment, though rural areas still experience high outage durations.

Note that PG&E in California has one of the highest SAIDI values globally, driven by frequent wildfires, hence causing grid shutdowns. In contrast, DEWA in the UAE maintains a very low SAIDI of just 1.6 minutes, showcasing world-class reliability.

Based on the benchmark, the following illustration shows a comparative view of average SAIDI and SAIFI values across key countries, highlighting their relative grid reliability.

Based on the best global practices, DSOs can adopt a combination of infrastructure, technology and regulatory strategies to enhance network reliability.

Infrastructure modernization and improvement

In regions prone to extreme weather, such as the US and parts of Asia, robust infrastructure is crucial for minimizing service disruptions. Investing in advanced, weather-resistant materials and systems, including comprehensive grid modernization initiatives, can significantly mitigate the impacts of environmental stressors.

• Increase the percentage of underground cables: reducing overhead power lines, particularly in urban areas, can significantly lower the risk of outages due to weather disruptions.  Such investments not only enhance the physical security of the grid but also improve its aesthetic qualities, contributing to urban development goals. However, cost constraints make this unfeasible in many rural areas.
• Grid reinforcement and upgrades: investing in transformers, substations and transmission lines ensures a more resilient grid, particularly in regions vulnerable to extreme weather events.
• Microgrid deployment: deploying localized microgrids can isolate faults and maintain supply during larger grid failures, improving SAIDI and SAIFI, particularly in remote regions.

Technological advancements through control and automation

Technological advancements have transformed the operational capabilities of DSOs, introducing efficiencies that were previously unattainable. Real-time data analytics, when integrated with grid operations, enable proactive management and swift resolution of potential disruptions

• Advanced Metering Infrastructure (AMI): real-time monitoring of energy consumption allows for faster fault detection and response, reducing outage duration.
• Automated reclosers: these devices quickly restore power after temporary faults, thereby minimizing sustained outages.
• Predictive Maintenance: using IoT sensors and AI-driven analytics, DSOs can detect equipment failures before they cause outages.
• Advanced Distribution Management Systems (ADMS): these platforms integrate data from multiple sources, enabling automated fault isolation and service restoration.

Regulatory incentives and flexible policies

Effective regulatory frameworks are instrumental in fostering innovation and ensuring the adoption of best practices in DSO operations. Countries with strong regulatory oversight, such as Belgium and the UK, have performance-based financial incentives to reward DSOs that improve SAIDI and SAIFI. Market-based mechanisms such as dynamic pricing and demand response programs can align consumer behavior with grid efficiency goals.

• Active Network Management (ANM): real-time control systems that help DSOs optimize distributed energy flows, avoid overloads and delay costly infrastructure upgrades. Already used in countries like the UK, ANM enables greater grid flexibility and improves reliability by preventing faults before they occur.
• Demand response programs: by encouraging consumers to shift electricity usage during peak hours, DSOs can reduce stress on the grid and minimize outage risks.
• Battery Energy Storage Solutions (BESS): these systems provide backup power and help balance grid loads during peak demand, reducing outage risks.
• Cross-border grid cooperation: flexible interconnection policies, such as those in Europe, allow for resource sharing and load balancing across multiple regions.

Enhancing Climate Resilience

An additional strategic pillar for DSOs involves enhancing climate resilience, implemented at both national and regional levels. This includes:

• Vegetation management programs: routine trimming and monitoring of tree growth near overhead lines to prevent storm-related faults.
• Wildfire and storm mitigation measures: use of fire-resistant poles, flood barriers and climate-resilient infrastructure to minimize service disruptions during extreme events.
• Resilience-focused infrastructure planning: designing network expansions and upgrades based on projected climate risks and environmental vulnerabilities to maintain long-term grid stability

Strategies like grid reinforcement or Active Network Management deliver strong performance but require significant investment and a high level of infrastructure or technological maturity. Underground cabling offers considerable impact on reliability, although comes with high costs and longer implementation timelines. In contrast, options such as automated reclosers or demand response programs enable quicker, lower-cost gains, making them suitable for DSOs seeking more agile improvements.

However, the best strategy will vary depending on each DSO’s maturity level, regional challenges, and its investment capacity. Therefore, this reinforces that no one-size-fits-all solution exists for reliability improvement. 

Western Europe (France, UK, Netherlands, Belgium)

These countries already benefit from a high level of grid reliability and a large share of underground infrastructure, especially in urban areas. However, aging infrastructure and climate uncertainties require continued investment.

• Invest in predictive maintenance and smart grid integration to address challenges of aging assets and increase automation in fault detection
• Expand underground cabling in semi-urban and rural areas, as these regions often still rely on overhead lines prone to storm-related outages
• Enhance demand-side response initiatives, leveraging smart meters already in place, to optimize consumption and reduce peak stress on the network.

Middle East (UAE, Qatar, Saudi Arabia)

The region features modern infrastructure, high underground cable ratios, and extreme climatic conditions such as sandstorms and floods.

• Deploy real-time grid monitoring technologies to proactively address faults in a high-temperature, high-dust environment and sustain world-class SAIDI/SAIFI levels.
• Expand battery energy storage solutions (BESS) to improve resilience and buffer short-term demand surges and improve resilience during peak loads.
• Avoid overinvestment in undergrounding where unnecessary (especially in less populated desert regions) to optimize cost-efficiency as UAE has already a high underground cable penetration.

North America (USA, Canada)

DSOs face wide-ranging environmental challenges, from wildfires in California to ice storms in Quebec and operate aging, overhead-heavy infrastructure. 

• Upgrade aging infrastructure to mitigate vulnerability of increasingly frequent extreme weather events (wildfires, storms,…).
• Expand microgrid adoption to provide backup power during extreme weather to rural and disaster-prone areas with decentralized backup solutions
• Regulatory frameworks should emphasize climate resilience incentives to drive investment in modernization and renewable integration

Australia

Australia combines remote grid operations, bushfire exposure and a high proportion of overhead lines. Urban reliability is generally high, but rural regions experience more difficulties. 

• Strengthen vegetation management programs to prevent wildfire outages.
• Expand microgrids and localized storage solutions to ensure supply in isolated and hard-to-reach regions.
• Avoid full undergrounding due to high costs in less populated regions instead targeting critical zones for selective investment.

The path to reducing SAIDI and SAIFI is not one-size-fits-all: it requires thoughtful and tailored strategies in operational realities, geographic challenges and technological maturity. While numerous interventions exist, certain strategic pillars have consistently delivered meaningful improvements across global DSOs.

Firstly, technology remains a crucial enabler. Solutions like Advanced Metering Infrastructure (AMI) and Advanced Distribution Management Systems (ADMS) not only enhance outage detection and resolution but also build the foundation for more flexible and data-driven networks. These technologies unlock real-time insights and automation that are essential for managing daily operations and unexpected crises.

Secondly, infrastructure modernization is a long-term investment with high returns. Whether it's reinforcing substations or increasing the underground cable ratio, modernizing assets can significantly enhance reliability, particularly in regions exposed to harsh climate or aging grid components. While undergrounding is costly, its benefits in urban or high-risk areas often outweigh the investment.

Finally, resilience planning must be embedded across the organization, from operations to strategy. The increasing frequency of extreme weather events makes it critical for DSOs to adopt proactive risk mitigation measures, such as wildfire prevention infrastructure, flood-resistant systems and vegetation management. These strategies reduce outage risk and enhance service continuity.

What stands out across leading DSOs is the presence of advanced tools but also the ability to integrate them in a unified and future-focused grid management approach. For DSOs and policymakers, the goal should be to create a culture of innovation, backed by regulatory frameworks that incentivize performance improvement and grid flexibility.

For the public, this means fewer outages, quicker recovery times and a grid that evolves with the growing demands of electrification, climate change and digital transformation. For DSOs, it means seizing the opportunity to transition from reactive operators to proactive energy enablers.