Export limits decide how much of your solar can flow back onto the street, not how many panels you can put on the roof. Plenty of Christchurch homes have arrays bigger than their export limit, and that is fine as long as the inverter is set up correctly and the paperwork matches.
This guide is drawn from Orion's March 2025 guide to connecting home generation of 15 kW or less, and from MainPower's distributed generation rules for North Canterbury. It explains the numbers, the inverter and paperwork steps, and how buy-back rates fit in.
How much solar can I export on Orion's network?
It depends on how many phases supply your house. Orion's limits are built around one idea: the imbalance between phases must not exceed 5 kW.
Many houses have a single phase supply, and those are capped at 5 kW of export. Two phase supplies can export 10 kW if it is spread evenly, and three phase supplies can export more as long as no phase runs more than 5 kW ahead of another.
Orion's network covers the city, Selwyn and Banks Peninsula, so these limits apply in Rolleston, Lincoln, Lyttelton and every city suburb. Our solar installation page covers how we size systems around them.
| Supply type | Orion export limit | Notes |
|---|---|---|
| Single phase | Up to 5 kW | Most houses |
| Two phase | Up to 10 kW | Must be spread evenly across both phases |
| Three phase | No more than 5 kW difference between phases | Balanced export can exceed 5 kW in total |
| Any supply | Recorded on the Certificate of Compliance | Set in the inverter |
What does the 5 kW phase imbalance limit mean?
It means Orion cares about how evenly export is spread, not only how much there is. A phase is one of the live conductors bringing power to your property; most homes have one, some have two or three.
If a three phase home exported 8 kW on one phase and nothing on the other two, the gap would be 8 kW and over the limit. Spread as roughly 3 kW on each phase, the same home could export 9 kW with no gap at all. The rule protects the local network from being pushed out of balance by lots of one-sided solar.
Not sure how many phases you have? A main switch that is a single lever usually means single phase, while a wide three-pole main switch or three separate service fuses usually means three phase. That is only a clue, so confirm it with your retailer, the lines company or an electrician before you rely on it for a solar design.
For most homeowners the practical takeaway is simpler. On a single phase supply, plan on 5 kW of export. If you want a large system and the property already has three phase, a three phase inverter that balances itself is usually the cleanest way to make use of it. Changing a single phase supply to three phase is a bigger job that involves the lines company and your switchboard upgrade options.
What are MainPower's limits in Rangiora and Kaiapoi?
MainPower is more generous. It approves systems up to 10 kW on single phase, considers three phase case by case, and applies a default export limit of 10 kW for small customers.
That default is lower in constrained parts of the network, and MainPower publishes a list of ICPs (installation control points, the number that identifies your connection) with lower limits. Check your ICP against that list before you design anything in Rangiora, Kaiapoi, Woodend or Pegasus.
From 1 October 2026 MainPower charges no application fee for systems under 10 kW, and its inverters must be on the Clean Energy Council list and meet AS/NZS 4777.2:2020. Our page on solar installation in Selwyn and Waimakariri covers both networks in the outer towns.
Want solar sized to your export limit?
Cheeky's Electrical designs systems around Orion or MainPower rules for your exact connection and handles the paperwork from application to certificate.
Do I need an Orion pre-approved inverter?
Not strictly, but it helps. The inverter must comply with AS/NZS 4777, and Orion says using one from its pre-approved list speeds up the application. The list is updated quarterly.
A non-listed inverter may still be accepted, but expect more questions and a slower approval. Ask your installer which inverter they plan to use and whether it is on Orion's current list before you sign a quote.
The inverter is also where the export limit lives. It is configured to stop export at your approved figure, and that setting has to match the paperwork.
What paperwork goes to Orion after installation?
Two documents, within ten working days. Orion requires the Certificate of Compliance and the Record of Inspection to be sent to it within ten working days of installation.
The Certificate of Compliance is the electrician's record that the work meets the electrical safety regulations and AS/NZS 3000, and it must state the export limit. All wiring has to be done by a registered electrician. You also need import and export metering, which your electricity retailer arranges.
If you are buying a house that already has solar, ask the seller for these documents. An electrical inspection can confirm whether the system on the roof matches what was certified.
- Orion application, before installation
- Certificate of Compliance, stating the export limit
- Record of Inspection
- Both sent to Orion within ten working days of installation
- Import and export meter, arranged through your retailer
How do solar buy-back rates work?
Your retailer pays you for each unit you export, at a rate it sets. Powerswitch describes the buy-back rate as how much a retailer will pay for each unit of solar electricity sent to the network, and notes that rates vary between retailers.
Powerswitch also says solar rates are not included in its estimates or savings calculations, so comparing plans takes a little manual work. Look at the buy-back rate and the price you pay per unit together, because a plan with a generous buy-back but expensive daytime power may not leave you better off.
The export limit and the buy-back rate work together. If you can only export 5 kW and the buy-back rate is lower than what you pay, the value of a big array comes mostly from what you use yourself, which is why we size systems around your daytime use rather than the roof area.
Are export limits going to change?
Possibly. The Electricity Authority is running reforms to export limits and connection fees through to 2030, so check the current rules before you rely on a figure for a long-term decision.
Cheeky's Electrical checks the live Orion or MainPower rules for your connection at the time we quote, and designs the system so that the inverter settings can be adjusted if limits change. If you are planning a larger system for an EV or a future battery, tell us at the start so the design leaves room for it.
Frequently Asked Questions
Can I install more panels than my export limit?
Yes. Export limits cap what leaves the property, not the array size. Extra panels cover more of your own use, especially in winter, but any surplus above the limit is curtailed by the inverter.
Who applies to Orion, me or the installer?
Usually the installer prepares and submits the application on your behalf, using the inverter and system details. Ask for a copy of the approval for your records.
Does the export limit apply to a battery too?
The limit applies to everything leaving the property at once. A battery that discharges to the network counts toward the same limit as the panels.
What happens if my system exports more than allowed?
The inverter should stop that happening. If settings are wrong, the lines company can require them to be corrected, so make sure the setting matches the Certificate of Compliance.
Is Lincoln on Orion or MainPower?
Lincoln and Rolleston are on Orion. Rangiora, Kaiapoi, Woodend and Pegasus are on MainPower, north of the Waimakariri River.
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