Ancillary Services Tender

2025 Ancillary Services Tender

Closing date for tender responses is 5pm on Wednesday 5 November 2025. 

The System Operator invites tenders for the provision of the following Ancillary Services for the period from 1 January 2026 to 31 December 2027:  

• Instantaneous Reserve: two-year term only
• Back-up Single Frequency Keeping: two-year term only
• Multiple Frequency Keeping: two-year term only
• Black Start (North Island): two-year term only 

Key Dates: 

• Tender opens: Thursday 9 October 2025
• Tender briefing webinar:  10:30am Tuesday 21 October 2025
• Tender responses due: 5pm Wednesday 5 November 2025  

Tender briefing: 

Below is the recording of the tender briefing held on Tuesday 21 October 2025.   

Q&A

Questions received during the tender process will be published here alongside answers from the System Operator.

Relating to administrative costs mentioned in the Procurement Plan, are these billable to ancillary service agents?

Administrative costs as discussed in paragraphs 57 and 58 of the procurement plan are not billed directly to ancillary service agents. The administrative costs to the system operator, if any, form part of the allocable cost of the ancillary service. The allocable costs also include the amounts paid to ancillary service agents for provision of the ancillary services. Allocable costs are collected by the clearing manager from the relevant party(ies), which may be Transpower (as the HVDC owner), purchasers and/or generators, depending on the ancillary service.

 

In other words, administrative costs are collected alongside the other costs of providing the ancillary service and are not invoiced by the system operator directly.

Invitation to Tender 

Update 28 October 2025: Minor updates have been made to the tables in Tender Response Form B (IR) and Appendix 1 of the Standard Terms Schedule for IR. We have made the following changes:

• For Interruptible Load: In place of "Hold Delay (ms)" we are now requesting separate figures for the "On Delay (ms)" and "Frequency Measurement Delay (ms)".
• For Generation Reserve: We have changed the column heading "Measurement Delays (ms)" to "Frequency Measurement Delays (ms)". We have removed the "Grid Sensitivity (MW/Hz)" column. 

If you have already submitted your tender response, we will require additional information from you relating to the change to the Interruptible Load tables. We will be in touch to arrange this. 

Invitation and terms and conditions

• Invitation to Tender
• Tender Terms & Conditions 

Tender response templates 

• Zip File (containing response letter and forms)
• Tender Response Letter
• Tender Response Form A - Deviations
• Tender Response Form B – IR (updated 28/10/2025)
• Tender Response Form C1 – MFK
• Tender Response Form C2 – BSFK
• Tender Response Form E - BS 

Draft Ancillary Services contract and schedules 

Zip File containing contract and schedules (updated 28/10/2025) Standard Terms Part A Standard Terms Part A1 Standard Terms Part A2 Standard Terms Part B

Standard Terms Schedule - IR (Instantaneous Reserves) (updated 28/10/2025) Standard Terms Schedule - MFK (Multiple Provider Frequency Keeping) Standard Terms Schedule - BSFK (Back-up Single Frequency Keeping) Standard Terms Schedule - BS (Black Start)

Other information

Ancillary Services Procurement Plan (located on the Electricity Authority's website) 

Tender Response

Please prepare your tender response in electronic format (in Microsoft Word and PDF), using the templates above.  

Tenders should be emailed to [email protected] by 5pm on the closing date listed above. Please include the phrase “Ancillary Service Tender Response” in the email subject line.  

All submitted responses will be acknowledged by reply Email. Note that information provided to Transpower is subject to the Official Information Act 1982. 

If you have any questions about the tender, you can contact the tender co-ordinator, Bridget Legg, on 021 718 404 or by email at [email protected].