What is on/off curtailment?
One of the issues affecting solar homes across Australia in 2023 is negative feed-in tariffs for solar exports at times. FiTs turning negative is a price signal from the energy market that there’s a lot of renewable energy in the grid in the middle of the day, and not enough demand for it (people to use it at that time). When there’s more renewable energy trying to enter the grid than is needed at that time, negative feed in tariffs mean you get charged to export.
There are a number of steps we’re taking to limit the impact of negative FiT for our customers - and there’s a bunch of ways you can increase your chances of ending up better off too.
Solar curtailment is one of these options. It involves Amber limiting the solar energy you produce during periods when FiTs turn negative, to restrict the amount you export at these times.
Who does on/off curtailment apply to?
On/off curtailment is available in the case that you have:
- Multiple Sungrow inverters
- One Sungrow inverter AND an inverter from another brand
- An AlphaESS battery AND a solar inverter from another brand
As of October 2023, all new incoming SmartShift customers who have this set up will have on/off curtailment auto-enabled as soon as they onboard.
(Alternatively, If you have an AC-coupled Tesla/AlphaESS/Sungrow battery with SolarEdge inverter and SolarEdge consumption meter, you can take advantage of Load-Following Curtailment once your system is configured. Learn more about Load Following Curtailment ).
How does on/off curtailment work?
If you have a setup that supports on/off curtailment, SmartShift may stop your solar production completely during periods of negative FiT. SmartShift will consider the house’s energy use, the cost to export and the cost to buy from grid, and choose the cheapest option.
In effect, what this means is that:
- If you’re not using much energy in your home at this time, SmartShift will direct your panels to curtail (generate zero energy) and you’ll pull from the grid instead to run your home. Given that this is occurring because FiT is negative, you can be confident that your usage costs from drawing from the grid will be extremely low.
- If you're using lots of energy at this time and SmartShift determines it would be cheaper to use your own solar, SmartShift will direct your panels to generate energy so you can benefit from using that no-cost solar to meet your energy needs. However, any excess that you can't consume at this time will go to the grid.
SmartShift will review the status of your house's energy consumption levels every five minutes to determine whether it makes sense to curtail or allow your panels to generate energy for your home.
Note: This curtailment will begin only once your battery is fully charged. When the wholesale grid price is <0c/kWh you will be getting paid to use power.
To learn more about negative feed-in tariffs and why they occur, head here.