Over the years, we have guided many Asset Owners to complete the generation commissioning process successfully. Below are their most frequently asked questions, and our answers to them. Use ctrl+F if you have a key word you are looking for. Otherwise, we have a section for general questions, and then the rest are divided by the commissioning phases. If you have questions that aren’t answered below, please reach out to [email protected].
General
Q: Do I need to engage with Transpower if I am connecting within a distribution network?
A: Yes, you will need to engage with Transpower in our System Operator role and may need to talk to Transpower in its Grid Owner role as described below. More information on what our role entails is available here.
If your generation capability will be greater than 1 MW, you will need to:
- meet the requirements of the electricity distribution business (EDB) that you are connecting to, and
- provide information to Transpower in its role as System Operator because there will be Code obligations you must meet. The specific obligations depend on the scale of your asset; see the section called Your Obligations on the Commissioning Generation page for more details.
Regarding Code obligations, 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 (EIPC). You might also find the New generation connecting to a distribution network FAQ helpful.
If your connection requires new Transpower assets or changes to existing Transpower assets, the distribution company will need to engage with Transpower to plan and develop those. It is worth noting that Transpower, in its Grid Owner role, must look after Transpower's grid assets and is interested in the impact of your project on the EDB's ability to comply with their obligations to Transpower at their point of connection (usually the local Transpower substation). See Transpower Grid Exit Point (GXP) impact studies for Distributed Energy Resource (DER) development to understand this potential impact.
Q: What happens if I connect to a constrained part of Transpower’s network?
A: 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, and you will always need to meet the relevant Code requirements that apply to your generating unit.
As stated in Workstream A of the Generation Connection Guide the Grid Owner undergoes a Concept assessment for each application, and it is during that early phase that you should identify thermal and voltage constraints. Note that connecting to a constrained part of the network may increase the risk of operational constraints with generation offers. It pays to carefully consider such elements and their implications from the beginning.
Q: How do I track which phase my project is in?
A: There is no online tracking tool for projects in flight. However, you can always check your own progress against the map in our GL-EA-404 Generation Commissioning Process document. You can also ask your lead engineer at the System Operator who will keep you informed about your commissioning requirements.
Q: What obligations do I have?
A: Your obligations depend on the generating plant size and the point of connection. Once you know your generator’s unit and station MW output, you can check the ‘Your Obligations’ section on our Commissioning Generation webpage for a brief guide, and then consult the Code for the specific obligations.
Feasibility
Q: What if my project includes inverter-based technology (e.g. wind, solar) – do I still have to work through the commissioning process with Transpower?
A: Yes, if you are considering inverter-based technology generation investment in New Zealand (whether you expect it to be connected directly to the grid or to a distribution network), you should contact Transpower as early as possible as you should with any other type of generation.
The New Zealand power system is small and isolated by nature. This means there are technical requirements for generation that can be more onerous than those found in the larger interconnected grids of other countries.
You might also find useful our Interim Requirements for Connection of New Generation Technology document. This provides guidance to support new types of generating technologies such as Battery Energy Storage Systems (BESS) and Dispatch Notified Generation (DNG) to enter the power system and wholesale market. This document has been prepared based on the current arrangements and obligations in the Code, which is subject to review by the Electricity Authority.
Q: What if my project doesn’t require an upgrade and just needs to make changes to an existing connection – do I have to work with the System Operator?
A: If you are unsure whether your commissioning project may affect the System Operator's ability to plan to meet or to meet its principal performance obligations, you must contact the System Operator for advice. Some guidance exists for Asset Owners in Clause 2(6) of Tech Code A in the Code.
Initiation
Q: What is the most suitable time to coordinate with the System Operator?
A: Best practice is for you to coordinate with the System Operator at least 12 months before when you first plan to inject power into the power system. We have highlighted this timing on the Commissioning Generation webpage. This lead-time allows Asset Owners to identify the critical elements of their projects based on complexity and the point of connection to the power system. Several of these elements, from protection coordination to establishing an ICCP connection, can take a long time. We have highlighted these in section 3.4 of our GL-EA-404 Generation Commissioning Process document.
Q: Who do I initiate my commissioning project with?
A: You will need to submit a [[form]] with the System Operator. This form will provide us with the information we need to assess your application and assign resources to your project. Read more about this in section two of our GL-EA-404 Generation Commissioning Process document.
Planning
Q: What is the project plan and how is it different from the Code commissioning plan?
A: The project plan showcases the scope of your commissioning project and its associated timings, which creates a baseline for the project to work towards. We capture the project plan within the DT-EA-1146 Kick-off Meeting Minutes Template. We agree on the project plan during the planning phase.
By contrast, you develop a commissioning plan during the delivery phase, and it lays out the key activities prior, during and after commissioning. We agree on these based on the timings in the project plan. The commissioning plan is prepared by an Asset Owner and is formally agreed to by the System Operator. It is more detailed, as you can see from our DT-EA-338 Code Commissioning Plan template, and you must adhere to it.
Q: Can the project plan be changed once we have moved beyond the planning phase?
A: The project plan is a baseline document to help ensure the scope and timing of your project have been considered upfront at the planning stage. Throughout the delivery phase, you, as the Asset Owner, may signal changes to the timeline. You can discuss these with the System Operator and capture them in meeting minutes.
Delivery
Q: When should the final protection coordination report be submitted?
A: Asset Owners and the Grid Owner both need to advise the system operator in writing that protection is coordinated across the grid exit point to which the generator connects. Without this written confirmation, commissioning will be delayed.
As indicated in the GL-EA-404 Generation Commissioning Process document, this is an activity that the System Operator does not oversee.
If connecting directly to Transpower assets, the Asset Owner must ensure that the protection is coordinated between their asset and the Grid Owner. By contrast, if connecting to Distribution assets, the Asset Owner must ensure the protection is coordinated between the Distributor’s assets and the Grid Owner’s.
Q: What does the Grid Owner require from Asset Owners to assess protection coordination?
A: You should submit the final protection coordination report to the Transpower Customer Solutions team or the assigned Transpower Grid Owner protection engineer at least 3 months before the planned commissioning date.
You should submit a written request which must include:
- a finalised Protection Coordination Report,
- a finalised Grid Owner Generator Interface Review, and
- a finalised Test Report.
Q: When should I organise the ICCP connection for my project?
A: The timing varies depending on whether you need to build a new ICCP connection, or whether you can use existing infrastructure for your project. If the former, then establishing the infrastructure for ICCP will be a long-lead item and therefore it will take many months. Refer to sections three and four of the GL-EA-404 Generation Commissioning Process document for more specific clarity.
Commissioning
Q: How long does it take the System Operator to review a hold point’s test results?
A: The System Operator aims to review hold point test results as quickly as practicable–normally, we can do this within 2 business days, assuming that the testing was conducted as planned and the test results meet the agreed criteria. However, it is important to note that assessment of results is only part of our process, and that we may also engage in activities such as peer review, modelling updates, and removing risks from the system.
Q: Why do I need to declare the end of the commissioning period?
A: During commissioning, one of the steps is to agree on secondary risks that your asset presents to the power system until all your control systems are proven. You will also have identified these as part of your Code commissioning plan. We model these risks in our market systems. The System Operator needs the Asset Owner to send a notification in writing to officially declare that the commissioning period has come to an end. The System Operator will then use this confirmation to request that the secondary risk be removed from the market system.
Closeout
Q: Why does the System Operator require multiple generator models?
A: We need generator models for power system analysis in the System Operator’s online and offline tools. Inverter-based resources interact with the grid differently to other types of generators. They bring a different set of challenges to the power system that need to be studied using power system analysis tools. Due to these different challenges, different types of studies need to be conducted (RMS and EMT) and these tools require the appropriate models.
The System Operator also provides an EMI (Electricity Market Information) case (with a Power Factory Power System Casefile) that is published on the Electricity Authority's website here. This is made available for public use to conduct power system studies.
Asset Owners are best placed to source generating plant through their vendors and equipment manufacturers. As mentioned in section three of the GL-EA-404 Generation Commissioning Process document, these models need to validated against test results to ensure that accurate plant performance is captured in our modelling. This step occurs in the closeout phase.
Q: Commissioning and testing are complete. What next?
A: Refer to the activities outlined in section six of the GL-EA-404 Generation Commissioning Process document. This will include updating your ACS with test results and the most up-to-date validated models of your assets. The System Operator will need to perform a final compliance assessment with the information you have provided.
Once the final compliance assessment is complete, it is your responsibility to ensure all of your assets always remain compliant with the Code, including during routine EIPC testing. You must notify the System Operator before making changes to assets, protection, ICCP, or control system settings.