From constraints to renewable abundance: Enabling Horizon Power’s massive rooftop solar growth in remote microgrids
Executive Summary
Horizon Power, Western Australia’s regional vertically integrated utility, set out to enable greater adoption of rooftop solar across its vast and remote electricity network. Operating some of the most geographically dispersed microgrids in the world, Horizon Power faced growing pressure from rising customer demand for clean energy and the technical limitations of legacy infrastructure.
Against a national backdrop where Australia leads the world in rooftop solar adoption, with more than 30 percent of households now generating electricity from rooftop systems
Horizon Power required a scalable and standards based approach to manage distributed energy resources safely and efficiently.
Through a pilot deployment in Onslow, Western Australia, and in partnership with SwitchDin, Horizon Power demonstrated how customer owned solar and battery systems could be integrated into microgrids using open standards. The project enabled the utility to continue approving new rooftop solar connections while progressing its decarbonisation objectives.
Challenges
Horizon Power supplies electricity to more than 36,000 households and 9,000 businesses across 2.3 million square kilometres of Western Australia, making it the power provider with the largest geographical catchment in Australia. Its network includes dozens of isolated microgrids serving regional and remote communities, many of which have historically relied on diesel or gas generation.
This reliance presents both economic and environmental challenges. Industry studies show that electricity generated using diesel in remote communities can cost three to five times more per kilowatt hour than electricity supplied through interconnected urban grids.
At the same time, customer expectations have been shifting rapidly. Australia now has over 4 million rooftop solar installations, and rooftop solar contributed more than 12 percent of national electricity generation in recent years.
Recognising this shift, Horizon Power sought to create a proof of concept focused on clean energy that aligned with the needs of its regional communities. Onslow was selected as the pilot location. With a population of approximately 900 people, Onslow is supported by 38 microgrids, a solar farm, modular gas powered generation, and a large grid connected battery energy storage system.
At the time of the project, Onslow had approximately 2,000 kW of installed rooftop solar capacity and 190 kWh of home batteries; pushing the local network to its hosting limit.
The existing network infrastructure was ageing and not designed to support two way power flows from customer owned generation.
As a result, Horizon Power could no longer approve new rooftop solar connections without risking grid stability.
This created a critical constraint, as the utility has a mandate not to refuse new customer connection applications.
The community had a wide mix of rooftop solar inverter and battery brands installed, creating integration and interoperability challenges.
The Horizon Power required a solution capable of coordinating, controlling, and scaling diverse distributed energy resources securely across multiple microgrids.
Solution
To address these challenges, Horizon Power partnered with SwitchDin to deploy a distributed energy resources management solution using SwitchDin’s edge devices.
SwitchDin’s edge devices are built on the international IEEE 2030.5 standard, enabling secure communication and control of solar photovoltaic inverters and battery systems regardless of manufacturer. This open standards based approach allowed Horizon Power to integrate customer owned DERs into its DERMS while maintaining full visibility and operational control of rooftop solar exports.
By deploying edge devices at customer premises, Horizon Power was able to dynamically manage exports, optimise local energy use, and maintain grid stability across its microgrids.
The solution also addressed scalability requirements, enabling Horizon Power to:
Work collaboratively with original equipment manufacturers and solar installers
Support future growth in distributed energy resources across its network
Reduce reliance on fossil fuel generation while retaining microgrids as a reliable back up when required
“Distributed energy resources hold great potential for regional communities, particularly where traditional fuels such as diesel often contribute to a high cost to serve electricity”
Results
Through SwitchDin’s scalable edge solution and extensive research and development focus, Horizon Power successfully integrated an IEEE 2030.5 client with its DERMS that could be deployed across its broader Western Australian network.
The solution enabled Horizon Power to confidently resume accepting new rooftop solar connection applications in Onslow. Customers were able to install rooftop solar and batteries from a wide range of manufacturers, supporting consumer choice while maintaining network safety and reliability.
With increased rooftop solar penetration, Horizon Power:
Strengthened the ability to reduce fossil fuel use across its microgrids, supporting both decarbonisation and cost reduction objectives
Demonstrated a practical and repeatable pathway for managing high penetrations of distributed energy resources in remote and regional networks
Conclusion
The Onslow pilot illustrates how regional and remote utilities can overcome grid constraints and ageing infrastructure through the use of open standards and distributed energy management technologies.
By adopting a flexible and interoperable approach, Horizon Power was able to meet customer demand for clean energy, maintain system reliability, and progress its long term decarbonisation strategy.
Horizon Power can now confidently accept new applications for the connection of new rooftop solar systems on its network. With more rooftop solar systems to be installed, Horizon Power has strengthened its position and ambitions as an innovator, environmental champion and political leader in the energy industry.
