Quarterly Operational Update

Quarterly Operational Update for the three months ended 30 June 2021 >GENERATION VOLUMES FALL - physical generation down 85GWh in the quarter, 126GWh across the full-year. >SPOT PRICES ELEVATED - elevated Q4 Spot prices reflect short-term fuel constraints, futures prices easing. >HEDGE PURCHASES LIFT - CFD purchases increase by 315GWh versus PCP as Mercury mitigates price risk. HYDRO GENERATION DOWN AS LOW INFLOWS PERSIST; GEOTHERMAL GENERATION IMPACTED BY KAWERAU OUTAGE Mercury's hydro generation in FY2021-Q4 of 727GWh (193GWh below average) equalled the prior comparable period for the lowest level of hydro generation in company history. This was due to sustained dry hydrology that saw Waikato catchment inflows at the 13th percentile for the quarter and at the 16th percentile for FY2021. Consequently, hydro storage in Lake Taupo ended the year at 143GWh below average. Geothermal generation decreased from 675GWh in FY2020-Q4 to 590GWh in the most recent quarter due to an unplanned outage at the Kawerau power station that started on 7 June. The station is currently expected to return to service this week. ELEVATED PRICES REFLECT CURRENT FUEL CONSTRAINTS WITH FUTURES EASING Average spot prices in the quarter reflected low national hydro storage and continued gas deliverability issues, increasing to $277/MWh at Otahuhu and $261/MWh at Benmore from $115/MWh and $102/MWh respectively in FY2020-Q4. Elevated prices were also seen in Mercury's CFD purchases for FY2021-Q4 which increased by 315GWh, from 464GWh in FY2020-Q4 to 779GWh, to mitigate price risk from decreased physical generation. Futures prices eased during the quarter due to a lift in national hydrology towards the end of June. FY2022 futures prices decreased from $193/MWh and $177/MWh at Otahuhu and Benmore at the start of the quarter to $170/MWh and $151/MWh respectively by the end of the quarter, with a subsequent further reduction to $144/MWh and $122/MWh as at 16 July 2021. COMMERCIAL & INDUSTRIAL SALES LIFT AS MERCURY POSITIONS PORTFOLIO Notwithstanding elevated spot prices, Mercury continued to engage with customers seeking to re-contract resulting in Commercial & Industrial segment sales (including both physical and financial) increasing by 227GWh, from 731GWh in FY2020-Q4 to 958GWh in FY2021-Q4. The Commercial & Industrial sales yield increased by 9.1% from $93/MWh in FY2020-Q4 to $102/MWh in FY2021-Q4. Customer numbers continued to decrease, dropping by 3,000 across the quarter to 328,000. This was reflected in Mass Market sales volumes which decreased by 63GWh to 672GWh versus 735GWh in the same quarter last year. DEMAND IN Q4 LIFTS VERSUS COVID-19 LOCKDOWN AFFECTED PCP; DEMAND IN QUARTERS 1-3 DECREASES Temperature-adjusted demand in FY2021-Q4 increased by 5.8% as the prior comparable period was affected by the COVID-19 Level 4 lockdown. Increases were seen across all sectors, with contributions from each sector being: urban (+2.5%), rural (+1.0), industrial (+1.2%), dairy (+0.8%) and irrigation (+0.3%). The recovery in Q4 drove full-year temperature-adjusted demand up by 1.0%. Excluding this period, demand in the first three quarters in FY2021 decreased by -0.6% versus the same quarters in FY2020, largely driven by reduced industrial demand due to production cuts at the Tiwai Point aluminium smelter, Norske Skog's Kawerau mill and the Marsden Point refinery. ENDS For investor relations queries, please contact: Tim Thompson Head of Treasury and Investor Relations 0275 173 470 For media queries, please contact: Shannon Goldstone Communication Manager Media phone: 027 210 5337 End CA:00375881 For:MCY Type:MKTUPDTE Time:2021-07-20 08:30:53