The future of electricity is being reinvented in Western Australia, writes Jeremy Wray of CPS National, who is working with Horizon Power to replace 54km of transmission with stand-alone power systems.

In an effort to stay ahead of the advancement of renewable energy, West Australian energy utility Horizon Power is disrupting itself rather than waiting to be disrupted by others.

As a national first, government-owned Horizon Power in conjunction with delivery partner CPS National is shrinking its own remote grid and providing a full electric utility service without expensive, higher risk poles and wires.

Horizon is a fully vertically integrated electricity service provider and has the world’s largest utility service territory, seven times the size of Germany. Despite the vast scale of operations, Horizon Power only has a customer base of just over 100,000 Australians. This creates some unique challenges.

Horizon Power has moved beyond technology trials to begin decommissioning and full removal of ageing overhead network. Remote network segments with defects have been identified and grouped into spurs, the first of which is the 54km Esperance feeder. Customers at the ends of spurs have been prioritised to receive supply from stand-alone power systems.

In the first tranche being rolled out, 15 stand-alone systems are being built to replace 54km of poles and wires. All the systems are completely independent of each other.

Plans into action

Utility-led decommissioning of existing rural network is a sensitive matter (socially, legally, politically and in terms of health, safety and environment). It involves transitioning customers from a familiar source of electricity to a different and unfamiliar technology. Despite the best efforts, customers can easily become fearful that they’re being left to “fend for themselves”.

From the customer’s perspective, the decommissioning of network is being done primarily for the utility’s benefit and they still expect the same or better supply of electricity.

From Horizon Powers’ perspective the utilization of stand-alone power systems (SPSs) is only viable and scalable where the quality and longevity of the asset is commensurate with utility requirements; the fleet of thousands of assets can be fully monitored and managed remotely (and ideally by one fleet-management platform), and; all deployment, maintenance and service functions are fully integrated with back office utility systems.

In other words, the technology requires whole-of-system integration and must ultimately become a new utility asset class.

New utility asset class

While several market actors are producing parts of this solution, Horizon Power found that no single vendor has commercialised a whole-of-system solution that is ready to scale to hundreds, let alone thousands, of systems; technology-agnostic and capable of seamlessly managing a diversity of systems; fully compliant with critical infrastructure cyber security standards, and; fully aligned with mandatory utility safety and operational requirements.

The partnership between Horizon Power and CPS National will change all that. The result is a full electric utility service offering without “poles and wires” as an entirely new utility asset class. The resulting stand-alone power systems are a “vertically-integrated utility in a box”, compliant with all utility safety, service, tariff metering and asset management obligations.

Sizing systems to customer demand

Horizon Power has utilised its advanced metering infrastructure to model the best stand-alone power system size for each site. The systems are sized to provide the same or better quality of supply compared to the old connection. The CPS design is modular and scalable, allowing for easy customisation.

Selecting panels and batteries

CPS National is technology agnostic, however in this particular instance we have opted for Jinko and Murata. Product selection of modules is a relatively straight forward consideration for this type of application, but a great deal of thought has gone into the selection of the batteries.

In making a determination on the right storage solution, considerable weight and emphasis was placed on lifecycle costing and safety. The Murata LiFe Po batteries come with a 15-year performance warranty, which gives great comfort to Horizon Power. Also, the phosphate chemistry is widely regarded as the safest of the chemistry types relative to alternative options on the market. Backup and support round out the value proposition.

Deciding battery size

The size of batteries is very much case by case and is of course governed by load data. For the purposes of reducing the associated costs attached to the project, all aspects of the build were designed with modularity and scalability in mind. This is particularly relevant with the battery cabinets that were designed in house at CPS.

Each cabinet can support 30kWh of the Murata LiFe Po batteries. In the event that additional storage is required, it is simply a matter of adding additional cabinets.

Energy management solution

Horizon Power has developed its own fleet management system for monitoring and controlling the new assets. The platform meets all the utility cyber security requirements and integrates into existing back office systems. The system provides the engineering teams, control centre and regional depots with live status, diagnosis and optimisation information from the SPS systems. This will allow Horizon to reduce costs by optimising across the fleet of systems.

Diesel when needed

Other than solar and storage, each site typically has a 16kVA genset with a 500L bundled tank for prolonged periods without sunlight.  

Genset run time will be contingent on load, which will vary between each site. In a traditional hybrid that incorporates a diesel genset a site will generally have 1.5 days of battery autonomy. The generator is there for prolonged periods of inclement weather, which is not unusual for the latitude of Esperance.

The systems are monitored by Horizon’s in-house operations team from its Remote Operation Centre. CPS National will provide technical support and backup to Horizon Power.

This initiative is an exciting first for Australia and CPS National is extremely proud to be supporting our valued partner in the delivery of this cutting-edge advancement.

Jeremy Wray is the national business development manager of CPS National.