This review is about enhancing transparency and future-proofing transmission prices for the future as Aotearoa New Zealand becomes increasingly electrified.
Purpose of the review
The TPM determines how Transpower recovers the annual cost of running the national electricity grid from our transmission customers.
We want to make sure the TPM continues to meet its intended objectives and that customers can easily understand and manage their transmission charges.
Since the Authority introduced the new TPM in 2023, we’ve listened to feedback from customers and investors about how it could work better, particularly around reducing uncertainty, volatility and complexity.
The Operational Review aims to improve the operation of the TPM, addressing potential issues identified by stakeholders and Transpower since the implementation of the TPM.
Key Objectives
- Refine adjustment mechanisms to reduce volatility and customer disruption.
- Reconsider the delineation between the simple and standard methods for calculating Benefit-Based Charges (BBCs).
- Improve BBC calculations and inputs to reduce complexity and reliance on judgement, enabling stakeholders to forecast charges with confidence.
- Ensure First Mover Disadvantage and Prudent Discount provisions remain fit for purpose in an evolving electrification landscape.
These changes aim to support stable, efficient pricing and help New Zealand transition to a low-emissions economy.
Workstream 1
Operational Review's workstreams
| Workstream | Focus area | Submission to the Electricity Authority |
| One - Adjustment events & quick wins | Adjustment events First Mover Disadvantage Enabling Code changes | April 2026 |
Benefit-Based Charge (BBC) Workstream (formerly workstreams two & three) | Simple Method BBCs Standard Method BBCs | TBC |
| Four | Regulatory alignment and any remaining issues identified in previous workstreams | TBC |
TPM Operational Review Industry Working Group
Members selected for the TPM Operational Review Industry Working Group (IWG):
- Alan Eyes – Blue Scope Steel
- Anna (Yuanjun) Wei – Fonterra
- Bas Van Esch – Vector
- Ben Gibson – Egen
- Dan Roos – Buller Network
- Darren Gilchrist – OJI Fibre Solution
- David Rohan – Contact Energy
- Dayle Parris – Orion Energy
- Mary Ann Mitchell – Independent Electricity Generator Association
- Nikki Stigley – Electra
- Paul Burnaby – Pacific Power
- Peter Apperley – Lodestone
This group is providing expert input into our operational review of the TPM, helping to refine the methodology and reduce complexity, uncertainty and volatility while supporting efficient transmission pricing.
We held our first IWG meeting in February 2026.
Click here to read the TPM Operational Review Working Group Terms of Reference.
- Work prior to the TPM Operational Review
Earlier in 2025, we worked with Concept Consulting to complete a two-stage Post-Implementation Review (PIR) of the TPM.
The PIR gave us valuable insights into how well the TPM is meeting its intended objectives, what’s working and where improvements could be made.
The review included:
- Stage 1: An online survey of stakeholders, including electricity distribution businesses, grid-connected customers, and electricity generators.
- Stage 2: Workshops to explore the key themes and ideas raised in the survey.
More information
For more information about the operational review, please contact us at [email protected].
You can find more information about the TPM here on our website.
The TPM itself is available on the Authority’s website.