Reducing the risks of wooden poles

Residents in remote Indigenous communities are benefitting from safer and more reliable power supplies
Residents in remote Indigenous communities are benefitting from safer and more reliable power supplies

It’s become something of a cliché to talk about the vastness of Australia and the challenges this presents.

For Horizon Power – Western Australia’s regional and remote electricity provider managing assets spread across of 2.3 million square kilometres – it’s an everyday reality. Nowhere is this more evident than in the Esperance District in the south of the state, where for every one customer there is 1km of network and nearly 25,000 poles to maintain.

Maintaining this asset base is more challenging given the long spur lines that criss-cross this network and the winter storms that bring lightning, strong winds and heavy rain.

With the challenges of the Esperance District in mind, Horizon Power has implemented a major new project involving the application of new testing techniques to reduce the risk of wood poles failing.

Project manager of the wood pole testing program Norman Dalley said it’s important for Horizon Power to improve the accuracy by which it identifies replacement poles that are at high risk of unassisted pole failure.

“The main objective of the trial was to identify, collect data and evaluate the wood pole testing techniques available in the market for their accuracy and ability to measure the loss of section that is used to determine the residual wood strength,” Mr Dalley said.

The testing and evaluation program was completed in August 2012 and PortaCAT Industries and Safer Power were selected as the preferred suppliers of the new technology that has now been implemented as part of business-as-usual activities.

“The old methods of wood pole testing provides a subjective assessment of the poles in WA, plus the invasive investigation provided an opportunity for fungal attack through the inspection holes, which ultimately leads to degradation of the structural integrity of the asset,” Mr Dalley said.

“The new technology we have implemented allows for a non-invasive wood pole testing methodology that uses gamma rays and ultrasonic technology to provide a representation of the inside of the pole without using an invasive process.”

The technology is a first in Australia. Nonetheless, Horizon Power says it will play a significant role in reducing unassisted pole failure rates in their service areas, and could be applied by other utilities.

In parallel with the new wood pole testing methodology, Horizon Power is also in the middle of a $14 million, two-year program of works to replace approximately 2000 wood power poles and reinforce an additional 5500 power poles in the Esperance District.

Depending upon their condition, untreated and unreinforced wooden poles may present a serious safety risk due to loss of strength at the ground line-making pole failure more likely. The serviceable life of untreated wood power poles is extended for up to 15 years if reinforced with steel at ground level.

Mr Dalley explained how the two programs complement each other.

“Together, the wood pole replacement /reinforcement programs and the new wood pole testing methodology will bring improvements to the safety and reliability of power supplies for our customers, which is our number-one priority and our ultimate goal,” he said.

“The added benefit for Horizon Power though is that we are achieving this goal in a way that ensures maximum value from the assets already in the field.”

Other projects on the Horizon

Horizon Power has several major projects underway that will improve the reliability of electricity supplies to tens of thousands of customers spread over one of the largest and most geographically and climatically-diverse service areas in the world.

Horizon Power generates, buys, distributes and retails energy to 45,000 customers in regional and remote Western Australia. The company maintains two interconnected networks and 38 isolated systems which power towns and communities throughout the 2.3 million square kilometres of land.

The North-West Interconnected System (the NWIS) operated by Horizon Power provides up to 140MW of power to the rapidly growing Pilbara region. By 2015, another 100MW of generation capacity is forecast to be required.

Powering the Pilbara

Two of the major projects currently underway at Horizon Power will increase generation capacity into the NWIS by 80MW within the next 18 months. 20MW of generation will be installed and operational in Karratha by December, in time for peak demand during the 2012/13 summer, and 60 MW will be installed in South Hedland for the summer of 2014.

The challenges posed by these projects are just part and parcel of project delivery for Horizon Power in the booming Pilbara region; labour shortages, significant input cost pressures as a result of the commodities boom and a substantial increase in fuel costs.

Over the past 10 years, costs in the Pilbara have increased about seven-fold.

Mungullah Power Station

In the west of the State, in the Gascoyne region, Horizon Power is putting the finishing touches on the new 18MW Mungullah Power Station which is expected to be delivering power by March next year.

Work to connect gas supply to Carnarvon’s new station is now complete and will enable the station to generate electricity efficiently using natural gas as its main fuel source.

The dual-fuel power station is now connected to the Carnarvon Lateral, which is located 600m from the power station and interconnects with the Dampier to Bunbury Natural Gas Pipeline.

Horizon Power Manager Generation Projects Craig Julian said the connection of the gas pipeline to the Mungullah Power Station will ensure that the power station can supply power from natural gas resources, which will mean the power is generated more efficiently and it’s a better result for the environment.

“The power station design allows for future growth in the town, so we can add additional generation and supporting infrastructure,” Mr Julian said.

The Mungullah Power Station, which is more than 6km away from the town, is due to be operational in 2013 and following completion, the existing Carnarvon Power Station will be decommissioned.

Aboriginal community upgrade projects

Horizon Power is in the process of upgrading electrical networks in five town-based and remote Aboriginal communities in the Kimberley under two major projects, which are delivering safer and more reliable power supplies.

Horizon Power is upgrading electrical networks and internal house wiring in the west Kimberley communities of Bayulu, Looma and Mowanjum and is building new power stations for the large remote communities of Yungngora and Kalumburu.

The electrical networks and house wiring in Yungngora, Kalumburu and Bayulu have already been upgraded and residents in those communities are now Horizon Power customers.

The communities of Looma and Mowanjum are expected to be completed by the end of the year. The power stations in Yungngora and Mowanjum are expected to be operational by the end of next year.