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Rapid Earth Fault Current Limiter (REFCL) reports

REFCL technology is designed to reduce the risk of electrical assets igniting bushfires.

REFCL Functional Performance Review

Due to two mild summers resulting from the current La Nina weather pattern, the planned functional performance review of Rapid Earth Fault Current Limiters (REFCLs) has been deferred until 2024.

As part of the initial 2020 functional performance review, Energy Safe Victoria undertook to carry out a further review in 2022. However, the unusually mild summers over the last two years have resulted in a substantial reduction in the number of times the REFCLs have been called upon to operate. This in turn means the data available for meaningful analysis is limited. The review will now be carried out in 2024.

Overview

In 2020, following the implementation of the first tranche of the delivery program, Energy Safe engaged Power Systems Consultants (PSC) to undertake an independent functional performance review of REFCL technology that is designed to reduce the risk of electrical assets igniting catastrophic bushfires. The scope of the engagement was broken up into three components and the key issues/outcomes are summarised in the review below.

  • REFCL Functional Performance Review:
  • Energy Safe Victoria Response to Recommendations:
  • Victorian Electricity Supply Industry (VESI) Response to Recommendation E:

Major electrical company (MEC) responses

Below are the redacted MECs responses to ESV’s REFCL Functional Performance review.

  • United Energy
  • CitiPower and Powercor
  • Jemena
  • AusNet Services

REFCL Cost-Benefit Analysis Report

ESV engaged Nous Group to undertake an independent cost-benefit analysis of the deployment of REFCL technology to review whether the investment in REFCLs is justified to reduce the risk of electrical assets igniting catastrophic bushfires. The key issues, analysis and outcomes are summarised in the below report and Addendum.

  • REFCL Cost-Benefit Analysis Report
  • Addendum to the Rapid Earth Fault Current Limiter Cost-Benefit Analysis

Applicable legislation and regulations

Visit our legislation and regulations page, to access the relevant legislation including

Victorian REFCL program status

Major Electricity Companies (MECs) have installed Rapid Earth Fault Current Limiters (REFCLs) at mandated zone substations across Victoria. The mandated REFCL rollout was completed in October 2023.

Delivery and time extensions

Energy Safe granted MECs various exemptions and time extensions in relation to the roll out of REFCLs.

REFCL Program Report

The MEC exmptions and time extensions are documented in the detailed REFCL program report, along with program delivery data:

A map of Victoria showing the REFCL network, colour coded to denote program status.

MEC delivery of REFCLs

Chart showing 3 tranches from May 2019 to Nov 2023

1 May 2019 to 1 Nov 2023

Notes:

  1. AusNet Services was granted a time extension for tranche 2 and tranche 3. AusNet has now completed delivery.
Chart showing 3 tranches from May 2019 to May 2023 - Target, Available for Service and At Required Capacity

1 May 2019 to 1 May 2023

Notes:

  1. Powercor has completed its mandated REFCL program.

Chart showing 3 tranches from May 2019 to May 2023 - Target, Available for Service and At Required Capacity

1 May 2019 to 1 May 2023

Notes:

  1. Jemena had two sites to deliver (Coolaroo and Kalkallo) by 1 May 2023. Jemena’s mandated REFCL program is complete.
  2. Kalkallo substation is owned by AusNet Services but supplies three feeders owned by Jemena.

About the program

The 2009 Victorian Bushfires Royal Commission (VBRC) found that some of the most devastating fires on Black Saturday were ignited by faulted powerlines.

The Powerline Bushfire Safety Taskforce

In response to the recommendations of the VBRC the Victorian Government established the Powerline Bushfire Safety Taskforce (PBST). The 2011 PBST Final Report identified Rapid Earth Fault Current Limiter (REFCL) technology as a potentially cost-effective way of reducing the risk of 22 kilovolt powerlines from starting bushfires (representing approx. 80-90% of risk), along with other initiatives to address the risk from powerlines more generally.

The Powerline Bushfire Safety Program

In 2011 the Victorian Government also established the Powerline Bushfire Safety Program (PBSP) to manage a $750 million program of works to deliver the VBRC and PBST’s recommendations.

The PBSP commissioned research and testing of REFCL technology in collaboration with Energy Safe, suppliers and electricity companies to confirm its capability in reducing the risk of powerlines igniting bushfires.

Following successful trials, the Electricity Safety (Bushfire Mitigation) Regulations 2013 were amended in 2016 to require electricity companies to achieve the 'required capacity' performance standard across 45 prescribed substations supplying the highest bushfire consequence areas of Victoria. REFCL was the only technology that could achieve this performance standard.

Delivery of the REFCL program was prescribed over three tranches, due for completion by 1 May 2019, 2021 and 2023 respectively. In addition United Energy has chosen to voluntarily install REFCLs on three of its networks.

A world first use of REFCL technology

Victoria’s use of REFCLs for bushfire prevention in rural areas with long lines, difficult terrain, and high vegetation cover is a world-first.

As with the implementation of any new technology, challenges were encountered. Energy Safe granted specific time extensions and exemptions to enable resolution of key technical and delivery issues that were beyond the control of the electricity companies who are required to deliver this ambitious program. Despite these extensions, the overall program rollout was completed prior to the 2023/24 bushfire season and is delivering the intended benefits to Victorians.

Bushfire ignition reduction

The PBST trials indicated that REFCLs could reduce powerline bushfire ignition risk between 48 and 60 per cent.

Following completion of tranche 1, Energy Safe commissioned two independent reports into the REFCL program in 2020 (see Cost Benefit Analysis and Functional Performance Review, on this page). The functional performance report found that the REFCLs are meeting this expectation.

How REFCLs work

A REFCL is installed in a substation where the high voltage powerlines it protects originate. It detects when there is a fault on one of the three wires that make up a high voltage powerline and compensates for this by rapidly limiting the energy released into the fault to such a magnitude that a fire is unable to be ignited. If the fault persists it will then instruct a circuit breaker to switch power off to the powerline.

Required capacity

Required capacity is the prescribed performance standard that REFCLs must achieve. This requires fault energy to be reduced so rapidly and to such an extent that a fire is unable to be ignited.

Further reading

  • The 2011 Powerline Bushfire Safety Taskforce Final Report

Date: 24/04/2024 2:43

Controlled document

The currency and accuracy of this document cannot be guaranteed once printed or saved to a storage device. If in doubt, please check the ESV website for the current version.

Reviewed 09 April 2024

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