Last updated: 17 Mar 2025
What are we doing?
We’re investigating what infrastructure is needed to support Waikato’s growing electricity demand.
Why are we doing it?
Waikato’s population and economy are growing, alongside increased electrification of transport and industrial processes.
By 2030, demand on Waikato’s regional 110 kV network is expected to reach 400 MW at peak times, up from 337 MW today. A key challenge is a ‘pressure point’ emerging at Hamilton Substation where the regional network connects to Transpower’s grid.
How will this affect you?
We're currently developing a shortlist of investment options, and we will consult on these options with the businesses and communities of Waikato. This consultation will help us determine the best option for meeting the region’s growing needs, and the effect this work will have on local businesses and communities.
In the meantime, we remain committed to ensuring that Waikato continues to have a safe and reliable electricity supply.
Timeline and updates
May 2024 – Long-list consultation
We explored various investment options through a long-list consultation. These options included investment in new transmission infrastructure, while also considering batteries and demand management solutions. We received eleven submissions.
Our summary of the feedback highlighted broad consensus among submitters on the need to invest in ensuring a reliable electricity supply in Waikato. The importance of resilience was also emphasised, along with the value of investments that may provide full or partial solutions to other existing constraints within the network.
2025 - Shortlist consultation
Our shortlist of investment options, and the results of our preliminary Investment Test, will be shared in a shortlist consultation. This is currently scheduled for late 2025. Following this, we will review submissions and, if required, prepare a Major Capex Proposal (MCP) for submission to the Commerce Commission in the first half of 2026.
Feedback from the long-list consultation highlighted that the need date for investment was sensitive to the changing demand and supply for electricity within the region. We engaged again with the local distribution networks to discuss and confirm their demand forecasts, as well as the possible options for shifting their load from the 110 kV to the 220 kV network, which may help to defer transmission investment
We are also applying our selection criteria to our long list of solutions. To support this, we have engaged engineering consultants to develop high-level designs and cost estimates for several of the options that are strong candidates for the shortlist.
Additionally, we have started to model the measurable benefits for these options which are inputs to our Investment Test analysis (see attachment 5 below).
More information
Non-transmission solutions
Alongside traditional infrastructure, we’re considering non-transmission solutions like grid-scale batteries and demand management – to help meet Waikato’s electricity needs efficiently.
As part of our Western Bay of Plenty MCP, we are trialling a new funding approach with the Commerce Commission. Specifically, we are seeking approval for a budget based on the deferral value of transmission investment, allowing us to delay transmission investment in the Western Bay of Plenty by one year. Please refer to Attachment 9 of this MCP for full details of that proposal.
If this approach is well received, we will apply a similar approach to the Waikato project. If successful, we will assess the required investment and delivery timelines and explore opportunities to economically defer some, or all, of the Waikato investment options using non-transmission solutions – where feasible – without compromising supply reliability.
Long-list consultation documents
- Main Proposal
- Attachment 1 - Overview of need
- Attachment 2 - Long-list of components
- Attachment 3 - Information for proponents of non-transmission solutions
- Attachment 4 - Scenarios
- Attachment 5 - Investment Test Parameters
- Summary of submissions
| Submissions | |
|---|---|
| EcoBulb | View |
| Harmony Energy | View |
| Mercury | View |
| Major Electricity Users' Group (MEUG) | View |
| Powerco | View |
| Renewable Generation Development (RGD) | View |
| SolarZero | View |
| The Lines Company | View |
| Venus Energy | View |
| Waipa Networks | View |
| WEL Networks | View |
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