Commissioning is an important workstream in the process of connecting new large loads to the power system to ensure that they operate safely and reliably. With the growing interest in large load customers wanting to connect, the System Operator has prepared this webpage to guide you through what is involved.
Similar to generation, ≥10 MW large loads can have a significant impact on power system security, planning, and operations and may therefore be subject to a range of information, modelling, testing, and commissioning requirements. We recommend engaging with us as early as possible to understand what applies to your project.
Getting Started
Working Definition
To understand applicable performance obligations, asset owners should consult the Electricity Industry Participation Code (especially parts 8 and 13) and the Connected Asset Commissioning, Testing, and Information Standard (CACTIS). At present, large loads are not explicitly defined in the Code; the System Operator's working definition is a consuming plant (or aggregation of consuming plants) which has a capacity of at least 10 MW, and is either:
- directly connected to the grid, or
- embedded within a distribution network where a sudden loss of load could affect power system voltage and stability by more than 0.5%.
We have defined this in more detail in the guideline below - see section 1. Note that as we welcome more large loads on the power system, we may adjust this definition ahead of a potential Code update by the Electricity Authority.
We are also conscious that different load types and technologies come with specific characteristics. Data centres, for example, pose unique stability challenges which necessitate specific modelling and power system study requirements, while some industrial loads with predictable and well-understood characteristics may be sufficiently represented with standard models. In defining requirements, we are carefully attending to those variations. Additionally, we are actively monitoring international experience and considering the New Zealand context to ensure requirements are appropriately tailored to different load characteristics while maintaining power system security and reliability.
Whether you are connecting via Transpower's grid or a local distribution network, make sure you are also aware of your obligations to Transpower as a Grid Owner - to learn more, refer to the guidance on the Help planning your connection webpage. Additionally, you will need to share real-time operational information with Transpower, which is explained on the Operational Data Integration webpage.
Technical Guideline for Commissioning Large Loads
We have prepared the document below to assist you on your connection and commissioning journey - see the Commissioning Generation webpage for a sense of the phases we will progress through with you.
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| We are working on multiple fronts to facilitate a smooth transition for large loads on the power system. A major component of this is maintaining power system stability, for which we need accurate quality information related to large load performance, studies, modelling, and testing. Our GL-EA-1370 Technical Guideline for Commissioning Large Loads seeks to fulfil this purpose, specifying what the power system needs from large load customers to safeguard security. Our guideline defines large loads in terms that apply to various sections of the document, from information sharing to operational communication and high-speed data requirements. The document is in its initial release. We are making further refinements to the specifications as we commission more large loads onto New Zealand's power system and as we learn more from the international power community. Read below for more about our future plans. |
Asset Capability Statement
To assist the System Operator to have visibility of large loads, customers must submit their Asset Capability Statement (ACS) by completing the Large Loads ACS spreadsheet. Email this along with the required information and any applicable diagrams and drawings in pdf format to [email protected].
If you are ready to initiate a commissioning project, click here to access our initiation form.
Coming Soon
Technical Specifications
In the short-term, we expect to update our guideline document above with further connection criteria.
In the medium-term, we expect aspects of this guideline to become codified in the Electricity Industry Participation Code and its documents incorporated by reference (like CACTIS). We will also expand our suite of technical documentation to supplement regulation and smooth the process for large loads in a variety of circumstances, similar to our suite of generation commissioning documents visible on our Commissioning Generation webpage.
We will also expand on the commissioning process to improve clarity of steps.
System Security Forecast
As part of the System Security Forecast, we assess security risks associated with continuing to supply electricity to all customers. As new large load connections progress through the connection application process, Transpower assesses their feasibility, operational impacts, and any associated network constraints. The System Security Forecast has identified a number of new data centre developments which are not included in the base load forecast data, two of which were assessed as sensitivities in the analysis. We expect to release the System Security forecast in December 2026.
BESS Enhancements
Investigations are underway to examine what requirements are appropriate for large load customers, including those with accompanying battery energy storage systems (BESS). The System Operator remains focused on implementing the BESS enhancement work – (a link should be available early next week for EA’s decision paper). This work will enable bi-directional offers, incorporate state of charge into scheduling and dispatch, and support full BESS participation in frequency keeping. Future BESS hybrid-station arrangements, including co-location with intermittent generation, should build on this work.
Market Considerations
Large loads cannot be adequately forecast through the medium-term load forecast process and therefore require non-conforming bidding to support the scheduling and dispatch process, security assessments, and market visibility.
Registration and listing in the participant register should be progressed with the Authority. Registered purchasers will obtain WITS access, submit and maintain bids, and meet clearing, prudential and reconciliation obligations.