In this article, we will dive deep into export limiting, exploring how it works and why it can be an advantage for many homeowners, even if you’re missing out on solar feed-in credits.
Key Takeaways
- Export limiting is a method where solar energy is restricted from being sent into the grid beyond a specified limit.
- Additional costs, such as installing a dedicated smart meter, are involved in implementing export limiting.
- Export limiting is different all across Australia, with some areas offering generous export limits while others impose heavy restrictions.
- Export limiting isn’t necessarily a bad thing, even if it’s limiting how many feed-in credits you’re receiving.
How Export Limiting Works
Export limiting works by restricting an inverter from sending more solar energy into the grid than a specified limit. This method ensures that the solar power system operates within its capacity and prevents grid overload.
The benefits of export limiting in solar power systems are mainly twofold:
- It allows homeowners to maximise their solar energy consumption by installing larger systems, reducing reliance on the grid and lowering electricity bills. Without the ability to limit the exports, a homeowner may be restricted to only installing a much smaller system.
- Limiting the energy exported helps stabilise the grid and prevents voltage fluctuations. Sometimes, voltage fluctuations can lead to over-voltage issues, which can also impact the production and savings of your solar system.
However, there are also cons to consider. Export limiting requires additional costs for installing a dedicated smart meter and may limit the potential income from selling excess energy back to your energy provider.
How to Identify If You’re Experiencing Export Limiting
Export limiting will often present itself in your solar monitoring data. The easiest way to spot it is to look for flat lines in energy production that sit below your inverter’s maximum capacity. Sometimes, you’ll see little spikes throughout this flat line, indicating moments of increased consumption.
Below is an image that provides a really good example of what your data might look like if your exports are being limited. Solar production is the orange part of the graph.
You can see that as the solar kicks in, production increases to about 10 kilowatts of power, with all excess energy production being diverted to the battery. However, when the battery becomes full, you can see a sudden drop in solar production into flat lines on the graph.
This is an indication that the system is experiencing export limits. You can also see that the solar feed-in back to the grid (dark blue) never goes above 5 kilowatts of export, indicating an export limit of 5 kilowatts.
Locations Where Export Limiting Is Enforced
Export limiting is enforced in most states in Australia.
In the more generous locations, properties can install much larger systems, while in others, the export limit may be zero, with heavy restrictions on the size of the solar system being installed.
In South Australia, they have introduced flexible exports, where your export limit will vary up to 10kW per phase – based on SA Power Networks’ assessment of network capacity in the area in which you are located.
Keep an eye on this space as other states look to implement similar initiatives.
Generous Export Limits
In these locations, you can typically install up to 10 kilowatts of solar inverter capacity with single-phase power and up to 30 kilowatts with 3-phase power. This means that very little to no limits will be placed on your exports.
Tasmania is one such location that offers a generous export limit to most residents. In NSW’s Ausgrid Network Area, which covers East Sydney, Newcastle, and out to Merriwa, export limiting is also allowed. Victoria’s United Energy Network Area, which includes a large portion of Melbourne on the east side of Port Phillip Bay and the Bayside Peninsula, is another good location for generous export limiting.
Restrictive Export Limits
In more restrictive locations, homes with single-phase power on the main grid can have up to 5 kilowatts of inverter capacity but can usually get around this limit by installing an export-limited solar inverter of up to 10 kilowatts. Three-phase homes can install up to 15 kilowatts of inverter capacity or 30 kilowatts with export limiting.
South Australia (SAPN) is one area with this restrictive export limit, as are VIC’s Jemena & AusNet network areas. Most of QLD also experiences this level of export limitation, although Energex can grant permission for single-phase homes on the main grid in SEQ to install up to 10 kilowatts of inverter capacity with export limitation. Other states will also allow larger systems to be installed with permission.
No Export Limiting
In areas where export limiting is not allowed, homeowners are typically restricted to installing solar inverter capacities of 5 kilowatts or less (single phase). Sometimes, larger systems are allowed. However, feed-in tariffs may only be offered for smaller systems.
Impacts on your solar feed-in credits
It is important to remember that even if you’re experiencing export limits, all the power your solar inverter can produce is available for the home to use. It’s also important to remember that the bulk of your solar savings comes from the solar energy you consume, not from what you feed back into the grid.
If you have a large solar system that is being limited in its exports, then in most cases, the reduction in your reliance on grid energy and the savings that come from that will far outweigh any drop in solar feed-in credits.
Every 1 kWh of solar energy you consume will be anywhere between 3-10 times more valuable to you than 1 kWh of solar feed-in. So, it’s always more important to install a system that meets your energy consumption needs than to worry about what limits might be put on your solar exports.
Even in a worst-case scenario, the power you’ll lose and the solar credits you’ll miss out on will be reasonably small.
If we consider a home in South Australia with a 10-kilowatt inverter, where no electricity is used during the day, and all the solar panels face directly north, then the percentage of output that will be lost due to a 5-kilowatt export limit would only be between 15-20%.
In reality, the losses will be even less. This is because even if there is only a refrigerator running during the day, it will reduce the losses from export limiting. Try to shift some of your electricity consumption to the middle of the day, e.g. by using timers on your dishwasher and washing machine, and your losses can be mostly or entirely eliminated.
Conclusion
In conclusion, export limiting can initially sound like a pain in the neck, with the potential to impact your solar savings; however, in reality, it can allow you to install a much larger solar system and does help to create a more stable and reliable energy network, and ultimately if you adjust your consumption behaviour to match, you’ll still come out on top.
By understanding the potential impacts of export limiting, you can make informed decisions to maximise the benefits of having solar.
If you would like help matching the right system to your household’s energy needs, book an assessment with one of your solar specialists.
