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Solar Export Limiting

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Solar Export Limiting: Why You Should Know About It

Table Of Contents

What Is Solar Export Limiting?

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.

Is solar export limiting good or bad?

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.

solar export limiting restricts you from exporting power to the grid

The Impacts Of Solar Export Limits

The Negative Impacts

Reports False Data

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.

Lose/Waste Energy

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.

May have an export limit of 0

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 Positive Impacts

Protects the grid from issues

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. 

Limited export means more power for home 

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. 

How Does Solar Export Limiting Work?

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.

How Much Power Can I Export To The Grid?

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.

Some areas with little or no solar limiting:

  • Tasmania 
  • NSW AusGrid network – East side of Sydney, Newcastle and Merriwa areas
  • VIC United Energy Network – East Melbourne, Port Phillip Bay and Bayside Peninsula

Areas with some solar limiting but can still see good feed-in tariffs

  • South Australia Power Networks 
  • Jemena Network (North & West Melbourne)
  • Ergon Network (South East Queensland) 
  • Horizon Power (Western Australia)
  • Endeavour Energy (West Sydney)
  • AusNet Network (Eastern 3rd Of Victoria)
  • EvoEnergy Network (ACT)

Locations with high export limiting

  • Western Power In Western Australia (Perth & South WA)
  • Powercor Victoria (Western Vic & West Melbourne)
  • Essential Energy NSW (Regional NSW)
  • NT PowerWater (Darwin, Alice Springs, Katherine)
  • CitiPower Victoria (CBD & Metro Area)

How To Overcome The Solar Export Limit

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.

Conclusion

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.

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Written By:

Luke Cove
Managing Director
Lightning Solar & Electrical

local brisbane cec installer

5 thoughts on “Solar Export Limiting”

  1. Quick question / statement…
    My understanding is the power back to the grid is capped to 5Kw per phase.
    Therefore, with a three phase system the total max power back to the grid would be 15Kw as there are three phases.
    I like to keep things simple and balanced.

    1. Your understanding is not quite right. The limit capped is based on who owns that section of the grid and how much power that grid can handle an influx of during peak solar production The power has to go somewhere, if its not been consumed, it has to go into batteries, or its limited, whether they cap you at 5, 10, 15 for single phase, and 15, 22, 30 for three phase, or higher for commercial, its not a multiplication of 5 from a single phase. Ie in Melbourne in the east they are all capped at 5kw single phase systems, yet here in the north west on Jemena, we can install a 10kw system, however regardless of your size, ultimately its the wholesale network that decides if you application will be allowed and whether you can export to the grid. It depends on a saturation point. they may decide they have too much solar in your area and give you an export limit of 0. If you look at the aemo website for realtime grid. When the sun is shining solar only accounts for a small chunk of Vic’s power, yet when its windy, wind generation accounts for 22 percent and dramatically drops the whole sale power, most of the time we still rely on gas and brown coal. So in the peak of the day when demand is low, there is a flood of solar with no where to go, so they scale down other generators, and install big battery projects, currently there is 22 planned for Vic alone, to soak up some of this extra power. Yet in SA solar accounts for 90% of there grid when the sun is at its peak, yet at night its gas and batteries. Look up who owns the poles and wires connected to your home, and you will be able to find out their limits on your area. If you install a battery as part of your system with limiting on export, you can install quite a large array that exports to your battery, to your house and then to the grid if any is left, which will get you around some of your export limits.

  2. Thank you so must for your information
    That your shared . It gives me the understanding on how solar system work.
    Especially on the export and import

  3. If my excess energy production (I have a 10kw system) over the 5kw allowed to be exported to the grid, is apparently still exported to the grid and I am being charged a service fee for every kw – does this mean that I am effectively being charged for power I supply to the grid for free? Ergon will not give me a straight answer.

  4. Hi there

    Can you clarify for me the terminology ‘5kw limit’?

    I am assuming that this value is not the total amount I can pass to the grid but the transfer rate. That is I can transfer only up to 5kw even if my array shows at a given time it is generating, say, 6kw? The reason I ask, and assume this is the case, is due to my supplier, ActewAGL, allowing feed in tariffs of 12c for first 8kw then 7c for any remaining amount transferred each day. Thank you.

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