Dry-year security response · emergency reserve scheme decided 13 January 2026, live by the last quarter of 2026
Where it stands: Emergency reserve scheme Code amendment decided 13 January 2026; Transpower building the service for the last quarter of 2026
The August 2024 gas shortage and historically low hydro storage forced industrial shutdowns and a policy reset. The Electricity Authority's answer is an emergency reserve scheme, decided on 13 January 2026: a new ancillary service run by Transpower that pays industrial users to reduce demand or add generation when supply is especially tight, worth an estimated $33 million in net benefits and due in place by the last quarter of 2026.
The problem
New Zealand runs a hydro system with only a few weeks of storage and no large interseasonal reserve, so a dry autumn in the South Island has always had to be covered by thermal generation. That backstop is eroding: domestic gas production has declined faster than expected, the Maui and Pohokura fields are past peak, and the thermal fleet that used to absorb a dry year is ageing and increasingly expensive to fuel. In August 2024 a fuel shortage and low inflows produced sustained high wholesale prices, industrial curtailment and a political crisis, and it exposed the fact that the market had no formal mechanism to buy emergency demand reduction before the system operator reached the blunt instruments of an official conservation campaign and rolling outages. The last time those were needed, on 9 August 2021, about 34,000 consumers were disconnected for up to two hours. Transpower's 2026 Security of Supply Assessment now shows the New Zealand Winter Energy Margin falling below the lower security standard by 2031 in its Reference Case, and, under an Expected Future Case with lower domestic gas supply and LNG imports from 2029, dry-year energy risk emerging as early as 2028.
What it does
The Electricity Authority consulted on establishing an emergency reserve scheme from 31 July to 28 August 2025 and on the Code amendment proposal from 17 October to 14 November 2025, and announced its decision on 13 January 2026. The scheme is implemented as a new ancillary service, operated by Transpower as system operator, under which industrial organisations opt in and are paid to reduce electricity demand briefly, or provide additional generation, for short periods when supply is especially tight and it makes commercial sense for them to do so. The Authority's research estimates net economic benefits of $33 million, and it judged the scheme significantly cheaper than investing in additional emergency generation; Transpower is working with providers to develop and implement it, with the scheme due in place by the last quarter of 2026. The Authority explicitly benchmarked the design against comparable mechanisms in Texas, Great Britain and Australia. This sits inside a wider security programme: Transpower consulted in late 2025 on amendments to the Security of Supply Forecasting and Information Policy covering improved forecasting tools, enhanced risk communication, updated contingent storage buffer settings and expanded system risk considerations, to be implemented before winter 2026; the Authority made frequency and voltage common quality Code amendments on 10 March 2026 and finalised the Connected Asset Commissioning, Testing and Information Standard on 31 March 2026 with the Code amendment decision published 18 May 2026; and from 19 May to 30 June 2026 it consulted on common quality and wholesale market arrangements for battery energy storage systems and hybrid stations and released a discussion paper on moving New Zealand to five-minute settlement. Transpower continues to publish electricity risk curves and simulated storage trajectories monthly and a quarterly security of supply outlook.
Market effect
An emergency reserve scheme puts a floor under the value of large industrial flexibility and a ceiling on the tail of the spot price distribution. For industrial consumers with interruptible processes it creates a second revenue line that was previously available only through bilateral arrangements with a gentailer, and it makes demand-side response a registered, dispatchable product rather than an informal favour to the system operator. For generators the effect is to reduce the frequency of the extreme scarcity events that reward peaking plant, which slightly weakens the merchant case for new thermal capacity at exactly the time the security assessment says more firm capacity is needed. The more important market signal is the gas trajectory: with the Winter Energy Margin projected below the lower standard by 2031 in the Reference Case and dry-year risk potentially emerging by 2028 if domestic gas falls faster and LNG imports do not arrive until 2029, the forward curve for winter cover in the late 2020s carries a structural premium that neither the reserve scheme nor the Code amendments remove. The battery energy storage and five-minute settlement workstreams matter for the same reason: New Zealand is building the market arrangements that let batteries and flexible load substitute for the thermal firming the system is losing, and the timing of those Code changes will determine how much of the 2028 to 2031 gap can be met without new gas-fired plant.
Key numbers
- Estimated net economic benefit of the scheme
- $33 million
- Implementation deadline
- In place by the last quarter of 2026, operated by Transpower
- Most recent emergency disconnection event
- 9 August 2021, about 34,000 consumers off supply for up to two hours
- Security of supply outlook
- New Zealand Winter Energy Margin falls below the lower standard by 2031 in the Reference Case, and dry-year risk could emerge by 2028 in the Expected Future Case
Who gains and who pays
- Large industrial electricity users (gains): Can opt in to be paid for short-notice demand reduction or additional generation under the new ancillary service.
- Households and small businesses (gains): An extra layer of protection against the unplanned disconnections last seen on 9 August 2021.
- Transpower as system operator (obligation): Must develop, procure and operate the scheme with providers by the last quarter of 2026.
- Peaking and thermal generators (costs): Fewer extreme scarcity events reduce the merchant value of emergency generation capacity.
- Battery storage developers (mixed): Gain from the firming gap but await the outcome of the 2026 BESS and five-minute settlement Code work.
Implementation
The scheme is a Code amendment creating an ancillary service, so Transpower must write the procurement and dispatch procedures, register providers and integrate the product into its security of supply toolkit before the last quarter of 2026; the Authority monitors compliance through its Compliance Committee and the Rulings Panel. It operates upstream of the existing emergency machinery, the Emergency Management Policy, official conservation campaigns and the Rolling Outage Plan, and alongside the amended Security of Supply Forecasting and Information Policy that took effect before winter 2026. The system operator continues to publish the annual Security of Supply Assessment, the monthly Energy Security Outlook with electricity risk curves and simulated storage trajectories, the quarterly Security of Supply Outlook and the New Zealand Generation Balance. The remaining structural questions, the future of the Huntly thermal station and its firming arrangements, the contractual position of the Tiwai Point aluminium smelter as the country's largest single load, and the government's gas supply interventions, sit outside the Code and are being handled through commercial agreements and government policy rather than regulation; those arrangements should be confirmed against MBIE and company disclosures before being relied on.
Concerns
- Declining domestic gas supply with LNG import capability not expected before 2029
- The Winter Energy Margin falling below the lower security standard by 2031 on current projections
- Reliance on voluntary industrial opt-in for a scheme that must work in the tightest hours
- Timely delivery of committed generation and battery projects, on which the near-term adequacy finding depends
- Emergency reserve payments and scheme costs being recovered from all consumers
- Market arrangements for batteries and five-minute settlement still only at discussion stage in 2026
Dates to watch
- 2026-12: Emergency reserve scheme due to be in place and operated by Transpower
- 2027: Authority decisions on battery energy storage market arrangements and the five-minute settlement discussion paper
- 2028: Earliest emergence of dry-year energy risk under Transpower's Expected Future Case
- 2031: Year the New Zealand Winter Energy Margin falls below the lower security standard in the Reference Case
Sources
- Electricity Authority: Electricity Authority announces electricity emergency reserve scheme (13 January 2026) and Code amendment decision paper, Electricity Authority Te Mana Hiko (official text)
- Transpower: Security of supply, including the 2026 Security of Supply Assessment and SOSFIP review, Transpower New Zealand (System Operator)
- Electricity Authority: Future security and resilience project, including 2026 BESS consultations and the five-minute settlement discussion paper, Electricity Authority Te Mana Hiko
- Electricity Authority and Commerce Commission: Energy Competition Task Force, established after the August 2024 fuel shortage, Electricity Authority Te Mana Hiko
Checked against sources on .