Powerco solar export limits and connection approval explained

Are you on Powerco’s network?

Powerco is the lines company for large parts of the North Island. The Electricity Authority’s EMI data groups its network into six areas: Tauranga, Taranaki, Manawatū, Whanganui, Wairarapa and Thames Valley. Powerco owns the poles, lines and transformers. It does not send you a power bill; your retailer does.

A region name is not enough to go on, because neighbouring towns can be on different networks. The reliable check is the ICP number on your power bill: Powerco’s website explains how to find it, and your retailer can tell you which lines company it belongs to.

Keep the three roles apart. Powerco approves the connection and sets the export limit. Your retailer arranges import/export metering and sets the price it pays for exported power. Your installer designs the system and submits the application.

Solar uptake on Powerco’s network is above the national figure of 4.2% of homes in three of its six areas, led by Wairarapa at 7.1%, 7th of the 38 network areas in New Zealand. Electricity Authority EMI figures for 31 August 2026:

Our regional solar uptake rankings compare all 38 areas and explain how the figures are counted.

The 10 kW limit

Powerco’s solar power for home and business page says it has increased the export limit for single-phase connections from 5 kW to 10 kW. It sets two conditions: the inverter must be approved and meet Powerco’s technical and safety requirements, and the network must have capacity for 10 kW of export at that point.

In its November 2025 submission to the Electricity Authority, Powerco said it already allowed single-phase connections to export up to 10 kW by default, and that it had not set lower limits anywhere. It supported a national 10 kW default, which the Authority’s export limits Code change brought in on 11 May 2026 for straightforward small home connections.

One document has not caught up. Powerco’s connection standard for systems up to 10 kW, last revised in August 2022, still lists 5 kVA as the maximum export for a single-phase inverter and 10 kW for a three-phase system. Powerco told the Authority it is updating the standard and uses an interim engineering instruction in the meantime. If you have three-phase supply, ask your installer what limit Powerco will approve for your connection, because its solar page does not give a separate figure.

An export limit is measured in kilowatts, which is power at one moment, not a daily allowance in kilowatt-hours. A typical home system only exports near 10 kW for short spells, if at all. Our system sizing guide explains how panel size, inverter size and export fit together.

Powerco’s constrained transformers

Powerco publishes a list of transformers that are nearing their capacity and are subject to export constraints. It says it does not expect any others to become constrained in the next 12 months. When we checked on 31 October 2026, the list was:

TE3-145 appears twice, once under Tauranga and once under Pyes Pa, so the list names eight distinct transformers. The addresses are where the transformers are, not the only homes affected: every house supplied from one of them shares the constraint. If you live on or near one of these roads, ask your installer to confirm with Powerco which transformer supplies you before you size the system for export.

Powerco told the Authority that on a constrained transformer a system may be limited by its own inverter, through the voltage response settings below, rather than by a lower export figure in the approval. It also said it is working on a congestion map, because a list is harder for homeowners to use.

From application to switching on

1. Quote and design. The installer agrees a system with you and checks the inverter is on the approved list.
2. Application. Your installer submits a distributed generation connection application through Powerco’s online service portal. It includes the ICP, owner and installer details, your retailer, the inverter make and model, whether volt-var and volt-watt responses are enabled, any battery, and a wiring schematic.
3. Powerco’s review. Powerco says it will tell you within five working days if it needs more information. Its published policy, which follows the Code’s timeframes, says a straightforward application under the simplified Part 1A route is approved or declined within 5 business days of being complete. An application on the fuller Part 1 route, for example where the inverter is not on the approved list, has up to 30 business days, which Powerco can ask you to extend by up to 20 more.
4. Notice to proceed. Once approved, you or your installer confirm within 10 business days that you intend to go ahead.
5. Installation and meter. The installer fits and tests the system to Powerco’s standards. Your retailer arranges a meter that records import and export separately, and you agree an export price with the retailer.
6. Certificate and commissioning. A certificate of compliance and a completed commissioning test statement go to Powerco. The installed equipment and settings must match the approved application.

Powerco may choose to come and test or inspect a system. For systems of 10 kW or less, its fee table lists no inspection charge.

What it costs to apply

Powerco charges nothing to apply for a system of up to 10 kW. Its fees for larger systems, which exclude GST, are:

That puts Powerco with MainPower, which also charges nothing for small home systems, and below Orion and EA Networks in Canterbury and Wellington Electricity, where fees for a home system come to about $160. The costs that remain are the installer’s paperwork and the retailer’s meter change, so ask whether both are in the quote. Our solar panel cost guide covers what else should be in the price.

Inverter rules

Powerco says an application will only be approved with an approved inverter. It points installers to its own approved inverter list and to the Clean Energy Council’s list, the Australian list that several Canterbury lines companies also use. If the inverter is not listed, the application needs a declaration of conformity or certificate of suitability for it and moves to the slower Part 1 route.

Powerco’s standard requires inverters to comply with AS/NZS 4777.2:2020 with its prescribed settings applied, locked and password-protected. It recommends that both the volt-watt and volt-var responses are switched on. In plain terms, the inverter turns its output down, or absorbs some reactive power, when the street’s voltage rises too high. On a sunny day with little load nearby that can trim a little export; it is what lets many homes on the same transformer export safely. The Electricity Authority’s Code now makes the “Australia A” settings in that standard the national default for small systems, which Powerco supported in its submission.

The standard also asks installers to check the voltage at the point of supply and report readings of 244 volts or more to Powerco. A high reading is an early sign that export will be trimmed, so it is worth asking your installer what they measured.

A grid-connected inverter switches off when the network goes down, so solar alone will not keep the lights on in an outage. Our battery storage guide explains what backup needs.

Older approvals and batteries

Powerco’s solar page says applications approved before November 2025 at the old limit can be reviewed for 10 kW export, on a first come, first served basis and subject to capacity. If your system was approved at 5 kW and your inverter can do more, ask your installer to request a review.

The application form asks whether batteries are installed, with their capacity, make and model, so adding a battery to an existing system needs a new application. Our battery or no battery guide shows how to judge a battery on what it saves.

Six things to get in writing

Use these alongside our guide to common solar quote mistakes when comparing installers.

• The connection: the ICP, confirmation that it is on Powerco, and whether the supply is single-phase or three-phase.
• The transformer: whether your home is supplied from one of Powerco’s constrained transformers, and the voltage the installer measured.
• The export assumption: the limit the savings forecast uses, and that it matches Powerco’s approval.
• The equipment: panel capacity and the exact inverter model, with confirmation that it is on Powerco’s approved list and will have volt-watt and volt-var switched on.
• The route: whether the application goes through the simplified Part 1A route or the slower Part 1 route, and why.
• The paperwork: who submits the application and notice to proceed, who tells the retailer, and who sends the certificate of compliance and commissioning statement.