Onslow Distributed Energy Resources Management System (DERMS)

We’ve connected traditional energy sources with distributed solar and battery solutions, to maximise the amount of renewable energy in Onslow. 

Project overview

We’re working to overcome the technical barriers of increased renewable energy on our network so more of our customers can install rooftop solar and reduce their energy costs.

We were tasked with implementing technology that would allow our Onslow power system to support a high penetration of customer and utility Distributed Energy Resources (DER) assets. The system aimed to deliver up to 50% of Onslow’s energy requirements through renewable energy. 

In November 2019, we completed commissioning of Onslow’s high renewable energy power system. The system contains a mix of distributed renewables, modular gas-powered generation and battery storage, with:  

  • 1,341 kW of residential solar PV (261 systems)  
  • 640 kW of commercial and industrial solar PV (8 systems)  
  • 190 kWh of residential energy storage (19 systems)  
  • 361 kWh of commercial and industrial smoothing storage (8 systems)  
  • 1 MW of utility solar farm  
  • 500 kWh of utility power station BESS  
  • 1 MWh of utility network BESS  
  • Centralised power station 

The system is managed through a Distributed Energy Resources Management System (DERMS). This is an intelligent software-based system that allows us to communicate with, and manage, the flow of solar energy into our grids.   

Managing the flow of solar energy

Distributed Energy Resources Management System (DERMS) is an intelligent software-based system that allows us to communicate with, and manage, the flow of solar energy into our grids.  

The system is designed to manage and optimise way thousands of grid-connected distributed energy resources (DER) work, to help balance supply and demand, keep the electricity system stable and provide long-term economic value. 

A world-first achievement

In a world first, this project has proved that it's possible to run an energy network on 100% hydrocarbon-free energy without any traditional backup generation.  
In a successful trial in May 2021, our Onslow microgrid was run entirely on clean, green solar and battery power for 80 minutes. 

Our partners

We partnered with PXiSE Energy Solutions to deliver the DERMS technology that allows our Onslow power system to operate as an advanced microgrid.  

A key component of the technology used was the Secure Gateway Device (SGD), delivered in partnership with SwitchDin. The SGD provides the grid edge communications and compute and control capability necessary to remotely control the behind-the-meter DER assets at customer properties via DERMS.  

We also partnered with our customers to make sure everyone involved could benefit - and make the most of the capability provided by behind-the-meter assets such as customer solar PV and our Battery Energy Storage System (BESS).  

Our strong relationship with our customers was critical to the success of the project, and our customers are now enjoying the benefits, including potentially lower energy costs.  

What does this mean for the community?

There’s no shortage of sunshine in Onslow.

We’re glad we took the advice of our grandson, Ash, who said we should look into this offer. We wanted to help the environment, and we’re also looking forward to the long-term ongoing savings on our power bills.

Long-term Onslow residents who installed a solar and battery storage system in May 2019

What's happening now?

We're testing the power of battery

DERMS has the ability to send commands to customer batteries and for them to react accordingly. We’re now exploring this further to try and optimise the performance of customer batteries by issuing instructions for them to charge and discharge at the most appropriate times of day.  
Community battery testing is under way and we’ll keep our community up-to-date with our findings.

Discounted solar PV and battery systems offered as part of Horizon Power’s Renewable Energy Pilot are no longer available for purchase.

This pilot has now ended and the work in Onslow is helping Horizon Power demonstrate and prepare for a renewable energy future.

The project is enabling the significant expansion of how much renewable energy we can accommodate on our networks and how the network impacts of high-renewable penetration can be managed for everyone’s benefit while ensuring the safety and stability of the network.

We're committed to bringing you more solar

In many of our regional towns, there is limited capacity to install additional rooftop solar because it can impact the reliability of power supplies and stability of the network. Pilot Projects allow us to connect and manage renewable energy systems for our communities, to potentially enable us to incorporate higher levels of renewables in the future.

Whilst the Renewable Energy Pilot has been completed, customers can still look to install solar in Onslow when capacity becomes available.

Stay up to date with solar

Frequently asked questions

  • What are the benefits of renewable energy such as rooftop solar?

    Renewable energy is a cleaner and increasingly cheaper source of electricity generation. For customers, rooftop solar has become very popular, helping to save money on electricity bills.

  • What are the challenges of too much rooftop solar?

    Our electricity networks were designed and built for one-way flow of electricity - from central power stations to customer homes along poles and wires or underground power cables such as in Onslow. Rooftop solar introduces a flow of electricity back into the electricity system, and if we get too much solar energy it can flow all the way back to the power station, causing power quality issues, and even causing the power station to stop working or blackout.

    The second problem is that solar energy is ‘intermittent’. This means that when a cloud blocks out the sun, rooftop solar energy is suddenly lost and can cause power generators at the central power station to struggle to meet the sudden spike in demand for electricity, causing damage to the electricity network and a loss of power or blackouts to homes and businesses.

    We understand that rooftop solar helps our customers save on their electricity bills and helps the environment. However, many of Horizon Power’s customers in other towns cannot connect rooftop solar until we solve these problems which is the focus of the Onslow Renewable Energy Pilot.

  • How did the Onslow Renewable Energy Pilot help?

    Onslow is a world-first demonstration project. With your help, our goal was to connect and safely and reliably manage as much rooftop solar as possible, to show how we can overcome the challenges of too much solar on a traditional electricity network. We did this by using an intelligent management system known as a DERMS (distributed energy resource management system).

    Horizon Power provided a generous financial incentive to customers to purchase and connect rooftop solar in Onslow, so we can safely prove we can manage a much higher volume of renewable energy. When we are successful, this will help safely increase the volume of rooftop solar connections across WA, ultimately helping other families reduce their ongoing electricity bills.

  • Could Onslow customers connect rooftop solar without the Pilot?

    Traditionally, the Onslow electricity network could safely connect about 850kWs of rooftop solar before we experience power supply issues. This is only the equivalent of about 100 residential rooftop systems and some small to medium business rooftop solar systems.

    The Onslow Pilot is now connecting around three times that amount of customers. Pilot participants helped us to solve the challenge as we use our distributed energy resource management system (DERMS) and the Secure Gateway Device to manage excess solar output from time to time.

    Keep up to date with new solar releases, following this Pilot, here.

  • I already installed a solar PV system as part of this Pilot, where can I find support?

    Customers who purchased and installed solar PV systems as part of this Pilot received a handover pack from Mechanical Project Services (MPS) specific to your property containing some maintenance, minor troubleshooting, product and warranty information.  A copy of your handover pack can be requested by contacting MPS on 1300 040 805.

    MPS provided a 12-month warranty period from date of your solar PV install.  Should you be experiencing issues please refer to you handover pack or contact MPS on 1300 040 805 for advice on how to proceed.

  • What is a Secure Gateway Device?

    A small electrical box called a Secure Gateway Device (SGD) was installed as part of your rooftop solar system. This device is required as part of meeting Horizon Power’s technical rules for connecting rooftop solar systems to the electricity network. The SGD provides a communications link between your rooftop solar system and Horizon Power’s distributed energy resource management system (DERMS) and helps ensure the stability of the Onslow electricity network during times of high solar generation and low customer demand for electricity.

    The SGD will be locked in its own wall mounted box nearby to your invertor and is the property and responsibility of Horizon Power.  The SGD is monitored by DERMS and by our teams remotely to ensure it is operating correctly and requires a stable internet connection to do so.  If you or your contractor suspects the SGD might not be operating as it should, please contact Horizon Power Karratha on 9159 7250.

  • How will Horizon Power be using the Secure Gateway Device?

    During the cooler months, not as much electricity is used by appliances such as air- conditioners, but your rooftop solar system is still producing energy, with the excess flowing into the electricity network.

    When customer rooftop solar systems export too much energy back into the network, we must temporarily reduce the amount of energy being produced from everyone’s rooftop solar systems to keep the network stable.

    We will be doing the same flexible generation management of Horizon Power’s large solar farm in Onslow. In summer, when customers use more energy, the reduction of rooftop solar generation is likely to be minimal.

  • For how long will my rooftop solar system be managed each time?

    On days where there is too much solar energy flowing into the electricity network, we will need to reduce the solar energy from your rooftop solar system, and this will be done for anywhere between a few minutes to several hours.

    This is an important part of the Onslow Renewable Energy Pilot and forms part of your ongoing customer agreement with Horizon Power.  Generous financial incentives were provided to customers for the purchase of rooftop solar and batteries as part of this pilot.

  • How can I reduce my electricity bill even further with solar?

    Once a rooftop solar system is installed, it is important to remember that your savings will depend on how and when you use energy. Here are a few energy use tips to help maintain your savings:

    • Use the same amount of energy as you did before you installed rooftop solar.
    • Keep you air-conditioner at 24 degrees and use fans where possible.
    • Use appliances while the sun is shining and you are producing solar energy, and
      conserve use at night.
    • Turn appliances off (including that second fridge) at the wall when not in use.

    Explore more energy saving tips here.

  • What are the factors that influence how much solar power I make?

    Sunlight angle and intensity
    Different seasons and constant day-night cycles have an effect on your energy generation efforts. Solar production can be ~40% lower in winter. This is primarily due to the angle of the sun and fewer hours of sunlight.

    Solar panel positions
    Panels that are located on the north/west facing side of your roof will have higher output, while south/east facing panels will be lower in output.

    Dirty panels
    Dirt and dust on your solar panels can reduce their output by up to 50 percent. Clean your panels regularly for optimal performance.

    How and when you use energy
    Aim to use electricity when your system is producing – set your appliances to run during the day and try to minimise power use at night. To achieve savings, its important not to start using more electricity than you normally would.

    Contrary to popular belief, solar panels are not the most efficient in the hot summer months. For every 10 degrees above 25 degrees celsius, the panel loses around 5 percent of its efficiency.

    The lower temperatures in winter will boost solar panel efficiency but because these days are shorter and the angel of the sun is lower, generation during winter is generally the same or lower than in summer.

    System management
    During the cooler months, not as much electricity is used by appliances such as air- conditioners, but your rooftop solar system is still producing energy, with the excess flowing into the electricity network.

    When customer rooftop solar systems export too much energy back into the network, we must temporarily reduce the amount of energy being produced from everyone’s rooftop solar systems to keep the network stable.

  • Can I monitor my own rooftop solar system?

    You can use Horizon Power app to see how much energy is exported each day.  Additionally, Fronius (invertor) and SENEC (battery) are the product manufacturers and may have Apps to show your rooftop solar system’s performance.

    Please refer to your handover pack or visit the product manufacturers websites to understand the best monitoring tool for your rooftop solar PV system.

  • Who can I contact about my system?

    Should you experience a fault or issue with your solar PV system, please refer to your handover pack provided by MPS or contact them on 1300 040 805 to request a copy.

    If you or your contractor suspects the SGD might not be operating as it should, (refer to What is a secure gateway device? above) please contact Horizon Power Karratha on 9159 7250.

More solar is on the way

We're working hard to make solar available to more of our communities, so no one misses out. 

Learn more

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