In short, a Generation Signalling Device (GSD) gives Energex and Ergon Energy the power to switch off your solar system. But how does it work, and is it cause for concern?

How does a GSD work?

A Generation Signalling Device is connected to the inverter. It works remotely by sending a signal via the power lines to activate what’s known as ‘DRM 0’ mode. When ‘DRM 0’ is signalled, the inverter shuts down. Consequently, your solar system stops producing energy and can’t export energy back to the grid.

When this happens, the Emergency Backstop Mechanism has been activated.

What is the Emergency Backstop Mechanism

According to Queensland State Government data released in September 2022, more than 722,000 Queensland homes now have solar power. And while it’s great news that Queensland is the nation’s leader in rooftop solar, our ranking presents challenges.

The biggest challenge we face is network stability – particularly at certain times of the day. With so many homes now fitted with solar, we often export too much to the grid.

When electricity demand is low, but export is high, it can cause problems for the network. The problem is known as ‘minimum system load’ and it can compromise the grid. In other words, homes within our network can experience blackouts.

So, to help protect and safeguard the network, and ensure we can continue to install rooftop solar, the Queensland Government has introduced the Emergency Backstop Mechanism.

When will the authorities activate the Emergency Backstop Mechanism?

The Emergency Backstop Mechanism is a last resort to prevent blackouts. Thankfully there are plenty of other measures in place to ensure our network is safe and secure.

According to Energex, it will only be activated under the direction of the Australian Energy Market Operator (AEMO) during emergencies. One example is when the main connection between Queensland and the National Electricity Market is offline at a time when PV generated energy exports are too high.

When the Emergency Backstop Mechanism is activated, a signal will be sent to the Signalling Generation Device, which will shut down your inverter.

Will I get a notification from Authorities?

You won’t receive notification when the relevant authorities activate the Emergency Backstop Mechanism and send a signal to shut down your inverter. This is because during an emergency, there is unlikely any time to do so. However the good news is that you can sign up to get a post event notifications from the AEMO here.

Will my solar system reconnect after the emergency?

When a situation is no longer an emergency, a signal will be sent to your inverter via the Generation Signalling Device. This will activate your system and it will resume operation.

In the unlikely event your inverter doesn’t receive the signal to turn on, the GSD has a built-in mechanism that will ensure it does.

Does every solar system need a GSD?

Not every system requires a Generation Signalling Device. From February 6 this year, all new and some replacement solar systems will require the device:

  • New connections with inverters 10kW or greater,
  • adding a secondary inverter to an existing system which results in total inverter capacity of 10kW or greater, and
  • replacing inverters greater than 10kW no longer under warranty.

For a complete list of the connections that require a GSD head to Energex and scroll down to the relevant table.

Can I disconnect the GSD?

The installation and connection of a Generation Signalling Device is a condition of your contract with the relevant electricity network – either Energex or Ergon. If you, or someone else removes the GSD, your inverter will automatically disconnect from the grid.

How much does a Generation Signalling Device cost?

If your solar system requires a GSD (in accordance with Network rulings), the device is automatically included in your Solenergy quote. And should you proceed with Solenergy, there’s no need to worry, it’s our job to ensure your solar system is compliant. Therefore, our accredited electricians will install the GSD on the day we install your solar.


Remember, authorities will only activate the Emergency Backstop Mechanism in an emergency. To learn more about the Generation Signalling Device and your requirements, download the official factsheet HERE.

If you have any questions or concerns about the Generation Signalling Device, get in touch – we’re here to help.