Quarterly Operational Update

Quarterly Operational Update for the three months ended 31 December 2023. QUARTERLY HIGHLIGHTS > NEW WIND GENERATION - Partially offset 25th percentile hydro inflows > TAUPO STORAGE CONSERVED - Providing a strong portfolio position for Q3 > ELECTRICITY YIELD GROWTH - Through mass market sales growth COMMENTARY MARKET SUMMARY Lower national inflows during the quarter were reflected in higher spot electricity prices averaging $156/MWh in Auckland. Forward prices remain high at $167/MWh in Auckland for financial years 2024 to 2026 as at 31 December 2023. NORMAL HYDRO INFLOWS IN DECEMBER AND PORTFOLIO MANAGEMENT HAS PROVIDED A STRONG Q3 STARTING HYDRO POSITION Lower quartile inflows in the Waikato catchment over the quarter saw Q2 hydro generation reduce to 928GWh (353GWh or 28% lower than PCP). Wind generation was higher at 579GWh (191GWh or 49% higher than PCP) this was primarily a result of new wind generation from Turitea South and Kaiwera Downs 1 wind farms. Strong hydro inflows at the end of the quarter and into January provides healthy storage leading into Q3FY24. Mass market yield growth was $16/MWh higher for the quarter relative to PCP, this was partly a result of one-off accounting adjustments and reduced acquisition activity. For the financial year we are forecasting full hydro generation of 4,000GWh. GENTRACK BILLING SYSTEM MIGRATION SUCCESSFULLY COMPLETED Electricity connections are flat on PCP and 5k lower compared to prior quarter, this quarter on quarter movement was primarily a result of focusing on customer migration. The programme of work to migrate to the Gentrack billing system has been successfully completed. [For Operational Statistics and Charts, please refer to the attached] ENDS Howard Thomas General Counsel and Company Secretary Mercury NZ Limited For investor relations queries, please contact: Paul Ruediger Head of Business Performance & Investor Relations 027 517 3470 investor@mercury.co.nz For media queries, please contact: Shannon Goldstone Reputation & Social Impact Lead 027 210 5337 mercurycommunications@mercury.co.nz End CA:00425182 For:MCY Type:MKTUPDTE Time:2024-01-24 08:30:18