Solar export limiting is where your local electricity provider sets a limit on the amount of energy your solar system can export into the grid.
Typically, this is around 5KW. You have a set limit on how much energy you can export (‘sell back’) to the grid.
A lot of Australian homes are not allowed to ‘sell back’ more than 5KW of their energy to the grid. So if you are looking for a system that is bigger than 5KW, then you may get hardware installed that limits your solar inverter from over exporting to the grid.
The reason why solar export limiting is in place is due to so many homeowners being able to produce their own energy. This means on a very sunny day lots of homes are producing a surplus of excess energy which will get sent to the grid and electricity lines. Most of these lines are old and were built years ago.
When too much energy gets sent at one time it results in power surges and issues. There is also a drop in the quality of the electricity as well.
We will go into much more details below but there are arguments for both. It does mean for some that the feed in tariffs are lost. However, we could argue that feed-in tariffs really don’t matter as much as you think.
As solar panels use sunlight to generate energy, it’s passed through your home and used in your electrical appliances. Some of this energy is unused and gets passed through to the grid to power other homes and communities.
However, if you have solar export limiting your excess energy is capped. Any power that cannot get through is usually lost or wasted in the inverter (usually through heat).
Let’s run through the positive and negative impacts of solar export limiting.
Severely impact the data from your solar system so you are unable to see if your system is performing or underperforming. All the data will ever show is your cap at 5KW. If your system is capable of producing more than this, you will never know if there are any issues or impacts from the data.
If your system produces more than 5KW but has a export limit, then energy is going to get lost or wasted. What’s more, it’s impossible to find out the amount of energy you are losing each day. It could be something really small or it could be a huge amount that’s wasted.
It could turn out that your home may even be excluded from exporting excess energy to the grid. If this happens, you are allowed to install a solar system to your home but won’t receive any feed-in tariff at all.
The reasons why these limits are in place is to prevent power shortages and issues. If everyone were able to sell their energy at the same time it can cause stress to the power lines. This will result in long/short term issues.
If your system has a limit on how much it can export then it means more power will get used in your home instead. Long term benefits would be a more energy efficient system.
Solar export limiting works by installing a smart energy meter to your switchboard.
When the energy passes through signals are sent to the inverter from the smart meter. Once your export limit has been reached, the smart meter will block any more energy from being sent to the grid.
This energy then gets wasted or lost usually as thermal energy (heat). The smart meter may cost you a little bit extra to your system as well.
Other ways may include software that is set up to block your inverter from exporting your limited amount.
Depending on whether or not you have an export limit, you should be able to export as much power to the grid as you can.
However, some areas won’t allow this and will instead cap you using solar export limiting. If you live in an area with a strong grid connection and not many people have solar then your limit will be less.
Homeowners who live in built up areas where solar is popular may have stronger solar limiting. Additionally, if you live regionally and the grid network is old, fragile and has a lot of issues you may have a solar export limit. Here are areas with the best and work export limits.
One of the best and most effective ways of overcoming solar export limiting would be to invest in a solar battery. Rather than export this power back to the grid, you store it in your solar battery. This means you then have power to use at night, during the day or in the morning.
None of your power is being wasted by the inverter if it’s capped to 5KW. Instead it’s being stored for you to use at a later date. Not only this but solar batteries can also prevent blackouts at your home. If the grid goes down your battery will be able to power your home until the sun comes up to charge it again.
However, solar batteries are not cheap. This would only really work for those people who have a large budget and can afford the high cost of the solar battery.
Well, there are both sides of the arguments for and against solar export limiting. I think it’s definitely something to consider when you are choosing the right solar system for your home.
Export limiting can also help you get a bigger system signed off for your home, so you can use it in your favour. However it may negatively impact some homeowners who aren’t allowed to export any excess energy to the grid.
Well you might think this is horrible but it doesn’t actually matter that much. Most homeowners don’t even have a system big enough to produce a significant amount of excess energy. Even if you did, the amount is so small it wouldn’t really bother you.
Lightning Solar & Electrical