Connect your network

We want to work with you to ensure your electricity distribution network has an appropriate connection to the National Grid given your network size and anticipated resilience.

Connecting your new network equipment to the National Grid takes careful and coordinated planning.  Please engage with us early so that Transpower (as Grid Owner and System Operator), our service provider network and you own teams and service providers can meet your expectations in delivering on an expanding programme of work.  

The overall process of connection is provided in the diagram below:

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 capacity is larger than determined by the GRS test, you must consult on the additional investment with your customers and seeks 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.

More questions?

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

New Distribution Connection - FAQs [ pdf 114.17 KB ]

Harmonic allocations - Large distributed energy resources [ pdf 107.4 KB ]

Transpower Grid Exit Point (GXP) impact studies for Distributed Energy Resource (DER) development.pdf [ pdf 128.27 KB ]