Background
In mid-2020 the Electricity Authority (Authority) published new transmission pricing methodology (TPM) Guidelines and tasked Transpower with developing a proposed new TPM. We delivered a proposed new TPM to the Authority on 30 June 2021, in accordance with the Guidelines and the Electricity Industry Participation Code 2010. The Authority made some changes to our proposal and consulted on it. On 2 December 2021, we submitted our response to the Authority's consultation paper. You can read it on our Regulatory Submissions page. The Authority made further changes after reviewing submissions.
On 12 April 2022 the Authority announced its decision to adopt the new TPM. The Authority's decision paper and the new TPM are available on the Authority's website.
In December 2022 we notified customers of their 2023/24 prices and updated our Grid Pricing web page with the relevant information.
Thank you to our customers and interested stakeholders who contributed to the development of the proposed new TPM that we submitted to the Authority. Your feedback and insights were invaluable as we worked to create a workable TPM.
Useful links
- TPM development process
- TPM development engagement
- Our work implementing the new TPM
- Our Grid Pricing web page
Indicative pricing updates
To help customers understand and prepare for pricing changes under the new Transmission Pricing Methodology (TPM), we published several indicative pricing updates after submitting our initial proposal to the Authority (which is below).
The purpose of publishing indicative pricing was to provide an example of what transmission charges could be if the TPM was applied to the 2022/23 pricing year. We also projected out to the 2034/35 pricing year to illustrate how indicative prices may evolve over time. We used a model we developed and updated during the TPM development phase (which comprised a number of process steps, databases and Excel spreadsheets). They were not formal calculations or notifications of transmission charges. We recommended anyone making decisions based on the indicative prices should consult the new TPM, any relevant information they have access to, and seek independent expert advice.
Indicative pricing updates:
- Indicative pricing update - August 2022
- Indicative pricing update - May 2022
- Indicative pricing update - April 2022
Additional support materials:
- Indicative Pricing Model
- Covered Cost Model
- Simple BBI customer and regional allocations model
- Indicative Pricing Stakeholder Information
Our 30 June 2021 TPM proposal to the Electricity Authority
- Letter from Transpower to the Authority TPM Full Proposal
- Proposed TPM (legal drafting)
- Proposed TPM 30 June 2021 compared TPM Preliminary Drafting 3 May 2021
- TPM Proposal Reasons Paper 30 June 2021
- Supporting Information for APP B Covered Costs Model
- Supporting Information for APP B Indicative Pricing Model
- Supporting Information for APP B Indicative Pricing Stakeholder Information
- Supporting Information for APP B Simple BBI customer and regional allocations
- Supporting Information for APP E and D CUWLP Data Processing Guide
- Supporting Information for APP E and D CUWLP allocation processing
- Supporting Information for APP E and D WUNIVM individual customer allocations and indicative prices
- Supporting Information for APP F TPM Adjustments and PDP Worked Example Spreadsheet
- Assurance Chapman Tripp
- Assurance Deloitte
- Assurance Ernst Young
- Assurance KPMG
Part one refer back proposal - non-Benefit Based Charge (BBC) aspects
We received a letter from the Authority (28 July), where it referred non-BBC aspects of the TPM proposal back to us for further consideration. On 25 August we resubmitted on these:
- Refer back letter from Electricity Authority to Transpower (part one - non-BBC)
- Transpower letter to the Electricity Authority re non-BBC TPM proposal referral
- Part 1 resubmitted proposed TPM (clean)
- Part 1 resubmitted proposed TPM (changes tracked with comments)
- TPM proposal refer back part 1 response
- TPM proposal refer back part 1 assurance letter
Part two refer back proposal - Benefit Based Charge (BBC) aspects
We then received a letter from the Authority (18 August), where it referred BBC aspects of the TPM proposal back to us for further consideration. On 15 September we resubmitted on these:
- Refer back letter from Electricity Authority to Transpower (part two - BBC)
- Transpower letter to the Electricity Authority re BBC TPM proposal referral
- Part 2 resubmitted proposed TPM (clean)
- Part 2 resubmitted proposed TPM (changes tracked with comments)
- TPM proposal refer back part 2 response
- TPM proposal refer back part 2 assurance letter Chapman Tripp
- TPM proposal refer back part 2 assurance letter Ernst Young
- TPM proposal refer back part 2 assurance letter KPMG
- Supporting Information for APP A to this response - clause 52 and 53 methods
- Supporting Information for APP B Covered Costs Model
- Supporting Information for APP B Indicative Pricing Model
- Supporting Information for APP B Indicative Pricing Stakeholder Information
- Supporting Information for APP B Simple BBI customer and regional allocations
- Appendix B of our TPM Proposal Reasons Paper
- Supporting information for APP D - Addendum to CUWLP case study
- Supporting information for APP D - EY assurance memo
- Supporting information for APP D - Allocation processing outputs with addendum
- Supporting information for APP F - Adjustments and Prudent Discount Policy
- Supporting information for APP F - Adjustments and Prudent Discount Policy worked examples