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.

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.

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.

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.

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.

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.

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.

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.

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.

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.

Temperature
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.

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.

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.