Help planning your connection

We want to work with you to ensure your new generation project is a success. Connecting new generation to the power system takes careful and coordinated planning.

The New Zealand power system is run on open access principles. You can request to build and connect anywhere you want but Transpower will always need to manage the integrity and security of the transmission system. You cannot buy or reserve transmission capacity on the transmission system.

Please engage with us early so that Transpower (as Grid Owner and System Operator), our service provider network and your own teams and service providers can meet your expectations in delivering on an expanding programme of work.

Our tailored approach

If you are building new generation greater than 1 MW you will need to comply with the Electricity Authority’s Code and Compliance and engage with Transpower in our role as System Operator. Read GL-EA-404 Generation Commissioning Process, or refer to the System Operator's Commissioning Generation page.

Most small assets (<40 MW) choose to connect via the local distributor's network as transmission level connections tend to be more expensive. At some sites a transmission level connection can still be a cost effective option.

Medium-sized assets need to consider the costs and capacity of both options. This should include an assessment on the impact on transmission pricing for you and the distribution company. You can talk to Transpower and the local distribution company about potential implications including connection charges. Transmission pricing is regulated by the Electricity Authority.

Large assets (>50 MW) will usually need to connect directly to Transpower's assets (e.g. a substation) if there is capacity. You will need to enter our connection application or investigation stage to access any spare connection capacity. If no suitable connection assets are available near your site or there is a capacity issue you may need to establish a new greenfield connection (costing upward of $20 million).

No two projects are alike, and many of the costs associated with your new connection will be specific to the site you build on and its location relative to existing transmission assets. Deciding where to connect to the national grid will have the most significant impact on connection cost.

Get in touch with us regardless of whether you are connecting with the National Grid or your local distribution company. We are here to help.

Service options and connection levels

We will work with you to identify the type of service you require from New Zealand’s National Grid and collaborate on the initial concept assessment. This can vary from a 24/7 ‘always on’ solutions with double-circuit connection and n-1 security in transformer and critical equipment through to lower resilience, lower cost connection solutions. Note, lower resilience connections often require additional operational constraints and extra commercial conditions, potentially including indemnifying Transpower for any associated new risks or increased whole of life operating costs.  Low resilience connections will not be feasible on critical parts of our Grid and are offered at Transpower's discretion.

As at July 2024 Transpower no longer offers Hard Tee connections for new connections to existing 220 kV transmission lines.

Minor changes to existing connections

If you need to make configuration changes to an existing connection, but don't require an upgrade, you will need to work with Transpower to coordinate changes to secondary systems. Our Protection & Automation Operational Engineering team can assess your need and advise how to proceed.  If this applies to you, please complete and return the following form: 

Standard Transpower conceptual designs for new greenfield connections

Transpower is developing standard conceptual designs for new greenfield customer connections.  The first of these covers a 220 kV single circuit in/out substation configured as either a Grid Exit Point (GXP) or Grid Injection Point (GIP).  Standard conceptual designs for other connection types will be developed over time.


Standard conceptual designs can be used to accelerate the investigation stage of a greenfield new connection project but will typically need some adjustment for site specific constraints.
The package includes detailed engineering designs as well as simplified layouts and spatial views suitable for inclusion as examples in a consent application.


Standard conceptual designs will be used by Transpower as a starting point for applicable Transpower connection investigations.  If developers or Engineering Consultants (ECs) wish to use a Transpower’s standard conceptual designs prior to a Transpower investigation or for a customer-led investigation the developer or EC must purchase a subscription to Transpower’s standards subscription service.  Third party use of Transpower standards without a subscription is not permitted.


More information on Transpower’s standards subscription service can be found on our Customer Information page.

Future decommissioning liabilities

For fixed term connection projects involving new Transpower lines and substations there may be future decommissioning liabilities recognised at the time of connection.  This will depend on the associated property arrangements and should be considered carefully from the outset.

Read this short guide and decision tree for more details on this topic.

Future Decommissioning Liability Guideline

Different connections

The three options below provide information relating to each connection type. 

Connect your generation

Do I need to engage with Transpower if I am connecting within a distribution network?

Yes. As state above, regardless of whether you are grid connected or distribution connected, if your generation capability will be greater than 1 MW you will need to provide information to Transpower and there will be ‘Code’ obligations you must meet. The Electricity Authority is the source for Code and Compliance information. Pay particular attention to Parts 3 through Parts 15 of the Electricity Industry Code of Participation. General guidance on your obligations can also be found in the system operator’s Commissioning Generation section. Also check out the 'Connecting generation through a local network' page.

For significant new distributor connected generation requiring new Transpower assets or changes to existing Transpower assets, the distribution company you are connecting to will need to engage with Transpower to plan and develop these. For more information see 'connect your network' below.

More questions?

Read all our documents below, and if not covered drop us a line with your specific questions: [email protected].

Generation Connection FAQs [ pdf 153 KB ]

Generation Connection Guide [ pdf 1.62 MB ]

Guideline Summary of Obligations [ pdf 85 KB ]

Protection Considerations for Generation Connections [ pdf 137 KB ]

Typical property requirements and timeframes for a new GIP substation [ pdf 481 KB ]

New Generation Connecting to Distribution Network FAQ [ pdf 112 KB ]

Harmonic allocations - New direct connects [ pdf 103 KB ]

Typical system study requirements for HV bus connected generation [pdf 138 KB]

Typical system study requirements for supply bus connected generation [pdf 138 KB]

Connect your industrial plant

Where do I go for protection information?

We have some resources for considering protection requirements as part of your connection:

2017 EEA Presentation [ pdf 801 KB ]

Boundary Protection Issues [ pdf 2.07 MB ]

More questions?

Read all our FAQs and information below, and if not covered drop us a line with your specific questions: [email protected].

New Industrial Load Connections FAQs [ pdf 102 KB ]

Guideline Summary of Obligations [ pdf 141 KB ]

Harmonic allocations - New direct connects [ pdf 103 KB ]

Connect your distribution network or distributed energy resource (DER)

Who pays to upgrade an existing connection?

For existing connection assets, at end of life, Transpower can fund replacement within our regulated capital expenditure limit, with a Modern Equivalent that meets the Original Service Potential.

  • A Modern Equivalent asset performs the same asset function with no significant increase in capacity, security or functionality, that would not be expected from buying a “modern” unit of the same type, built to current day standards.
  • Original Service Potential is defined in terms of the existing assets capacity and level of security taken in context of the installation surrounding the asset. This includes ensuring the asset is fit-for-purpose to avoid a near-term upgrade using Transpower’s prudent load forecast.

For a connection asset replacement or a connection enhancement Transpower will also complete a consultation assessment under the Grid Reliability Standard (GRS) as defined in the ‘Code’.  This test will identify the most economic connection asset capacity within the constraints of the GRS.

The connecting party can accept the replacement assets option Transpower can fund within our regulated capital expenditure limit or, request a different capacity connection asset based on their own need assessment provided;

  • if the chosen capacity provides a lower level of service, the connecting party must seek approval from the Electricity Authority
  • if the chosen capacity is larger than determined by the GRS test, the connecting party must consult on the additional investment with their customers and seeks approval from the Electricity Authority

Our regulators promote ‘beneficiary pays’ as a general principle across all areas of capital expenditure. Fully funding a capacity upgrade through the Transmission Pricing Methodology (TPM) may represent a material change in “original service potential” to the benefit of a single customer and displace other investments within our regulated allowed capital expenditures.

Transpower will consider a small increase in capacity during a replacement to maintain the original service potential for its expected life. This capacity would be determined through carrying out an economic assessment (similar to the GRS) using Transpower’s expected load forecast (P50 forecast), excluding any speculative step or trend changes.

For connection asset replacements where the customer choice proposes development of a higher specification asset, the incremental cost (above straight modern equivalent replacement) must be funded through a Transpower Works Agreement (TWA) or alternate independent funding.  The replacement only cost can be fundable via the Connection Charge component of the TPM.

For new connections or enhancements to existing connections not due for replacement, the full project cost must be funded through either a TWA with Transpower or alternate independent funding. This also applies to customer requested upgrades to interconnection assets outside Transpower’s RCP funding envelope.

Is the Grid Reliability Standard (GRS) relevant to my connection?

The GRS is an economic test Transpower must use for investments in new interconnection assets under our regulated capex input methodology.

Connection assets investments do not need to pass the GRS. For new connection assets the GRS is used as a consultation test. If your chosen assets resilience or capacity is higher than determined by the GRS test, you must consult on the additional investment with your customers. If significantly higher or lower you will also need to seek approval from the Electricity Authority prior to confirming the investment.

Security / capacity at my GXP is becoming constrained, what are my options?

If your connection is forecast to become constrained, you need improved reliability, or you believe you need an upgraded connection for some other reason, Transpower can undertake a concept assessment including:

  • identifying options including “traditional” grid / network enhancement options for customer investment and/or DG or other non-transmission options
  • feasibility, high level cost, timeframes and risks for the options identified
  • if requested a GRS study

What happens if I connect to a constrained part of Transpower’s network?

The New Zealand power system is run on open access principles.  You can request to connect anywhere you want, but Transpower will always need to manage the integrity and security of the transmission system.  You cannot buy or reserve capacity on the transmission system.

You can find more information on constraints in our Transmission Planning Report. To understand the uncertainties at play when considering investing, refer to the Investment Uncertainties section (in 2019 TPR, Section 3 Investment Uncertainties).

New connections to constrained parts of our network may also require wider system upgrades to provide you with the level of reliability you require.  If these include upgrades to interconnection assets that do not meet the Grid Reliability Standard (GRS) investment test, the cost of these wider upgrades will need to be included as part of your connection investment.

Where do I go for protection information?

As an existing Transpower customer you are welcome to log in to our customer area to access protection information here.

When does Transpower care about connecting generation or storage to a distribution network?

When connecting any generation ≥ 1 MW to a distribution network, in addition to meeting the requirements of the Electricity Distribution Business (EDB) you are connecting to, you will also have obligations to Transpower.  Obligations to Transpower typically increase with the size of your project.

Transpower as System Operator has requirements for commissioning any generation ≥ 1 MW.  See the system Operator’s Commissioning Generation page for more information.

Transpower as Grid Owner is interested in the impact of your project on Transpower’s grid assets and the impact of your project on the EDB’s ability to comply with their obligations to Transpower at their point of connection, typically the local Transpower substation.  To understand this potential impact see the guideline on ‘Transpower Grid Exit Point (GXP) impact studies for Distributed Energy Resource (DER) development’ below.

More questions?

For more answers to your questions check out our FAQs below or send us an email: [email protected] 

New Distribution Connection - FAQs [ pdf 114 KB ]

Harmonic allocations - Large distributed energy resources [ pdf 107 KB ]

Transpower Grid Exit Point (GXP) impact studies for Distributed Energy Resource (DER) development [ pdf 128 KB ]

Typical system study requirements for large embedded generation [pdf 138KB]

 

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