Quarterly Operational Update

22/04/2026 08:31 NZST, MKTUPDTE

3Q-FY26 Trading update for the three months ended 31 March 2026.

QUARTERLY HIGHLIGHTS

> Ngā Tamariki geothermal station OEC5 successfully opened and reliability run completed. The new unit is on time and on budget and expected to increase the site generation by 390GWh per annum and net output by 46MW.

> Committed to the next phase of the hydro refurbishment programme. Contract signed with international technology group ANDRITZ, supporting the long-term resilience and performance of the existing asset base.

> Datagrid New Zealand and Mercury signed a 140MW power purchase option agreement enabling new demand and AI infrastructure growth in New Zealand.

> First generation from 11 turbines installed at Kaiwera Downs Stage 2 wind farm started ahead of schedule in April, reflecting continued focus on delivering generation development uplift.

MERCURY DELIVERS STRONG Q3 PERFORMANCE

Mercury delivered a strong third quarter, with higher renewable generation and disciplined portfolio management supporting trading margin of $325m, up 27% on PCP. This is reflected in our upgraded FY2026 EBITDAF guidance to $1.05b, announced today.

The quarter also reflects continued delivery across our renewable development and asset renewal programmes, with important milestones achieved at Ngā Tamariki, Kaiwera Downs and in hydro refurbishment.

Overall, this performance highlights strong operational momentum and disciplined execution against our strategic priorities. We look forward to discussing the strength of our geothermal platform and future opportunity in more detail at our Geothermal Investor Day on 14 May.

- Mercury Chief Executive Stew Hamilton

Trading Margin $325m

> Up 27% on PCP

> Up $69m on PCP

> YTD Trading Margin up $172m to $1,031m

Generation Volume 1,997GWh

> Up 286GWh on PCP

> YTD Generation volume up 824GWh to 6,726GWh

Hydrological Inflows 76th percentile

> Up from record low PCP

> YTD Inflows were at 86th percentile compared to 3rd percentile PCP

[For Operational Statistics and Charts, please refer to the attached]

ENDS

Howard Thomas

General Counsel and Company Secretary

Mercury NZ Limited

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