Meridian Energy monthly operating report for December 2025

Wednesday 21st January 2026

Meridian Chief Executive Mike Roan says it’s been a wet spring and early summer, which has been good for the company and broader electricity market.

“We’ve begun 2026 in a very strong position when it comes to hydro storage. Inflows, current storage and remaining snowpack are all well above the long-term averages, which has meant we’ve had extended periods of spilling in both the Waitaki and Waiau catchments since early December.”

“This has resulted in low wholesale prices. Our average generation sales price was under $7 per Megawatt Hour in December, and an average of $77 for the first six months of this financial year, half the level of the same period last year. As the authors of the Frontier report said, that’s the wholesale market working as it should,” says Mike Roan.

“Overall, we’re generating and selling more at this point of the financial year than we were a year ago. Generation volumes are 13% higher, and retail sales volumes 12% higher than the first half of the last financial year. Our customers numbers are also growing, with total connections 19.5% higher than in December 2024.”

Key points this month include:

In the month to 12 January 2026, national hydro storage decreased from 153% to 115% of historical average.

South Island storage decreased to 113% of average and North Island storage decreased to 126% of average by 12 January 2026.

Meridian’s December 2025 monthly total inflows were 123% of historical average.

To date this financial year, total inflows are 144% of historical average, the second highest July to December inflows on record.

Waiau catchment inflows in December 2025 were 147% of historical average.

Meridian’s Waitaki catchment water storage at the end of December 2025 was 138% of historical average.

Snow storage in Meridian’s Waitaki catchment was at 124% of average in early January 2026.

Water storage in Meridian’s Waiau catchment was 131% of average at the end of December 2025.

December was unsettled, with alternating hot and cool spells and a wet end to the month for many areas. Temperatures were average or above for most of the country, with a wide variation in rainfall totals compared to regional averages.

National electricity demand in December 2025 was 4.3% higher than December 2024.

New Zealand Aluminium Smelters Ltd (NZAS) average load during December 2025 was 574MW, compared with 485MW a year ago, when Meridian was exercising call options under the demand response agreement.

Meridian’s retail sales volumes in December 2025 were 4.5% higher than December 2024.

Compared to December 2024, segment sales in residential were 26.4% higher (including ex customers of Flick), small medium business 9.5% higher, large business 13.5% higher, agriculture 3.2% lower and corporate 2.4% lower.

Key points this quarter include:

Q2 total inflows were 159% of historical average, the 4th highest Q2 inflows on record and 41% higher than Q2 last year.

Meridian’s Waitaki catchment water storage at the end of Q2 was 2.2% higher than Q2 last year.

Compared to Q2 last year, Meridian’s generation was 12.3% higher at a 9.2% lower average price.

2026 electricity futures prices decreased during Q2.

National electricity demand in Q2 was 5.6% higher than Q2 last year.

Spring 2025 was the warmest spring on record, with temperatures above average almost everywhere. Most of the country experienced a wetter than average spring, except for eastern areas of both islands.

Earth Sciences summer 2026 outlook sees current weak El Niño conditions present in the tropical Pacific, with ENSO-neutral conditions expected. This suggests higher than average temperatures across the country and variable South Island rainfall.

At the end of Q2, Meridian’s customer numbers were 19.5% higher than at the same time last year.

Compared to Q2 last year, Meridian’s retail sales volumes were 10.3% higher, with increases in all segments, at a 6.4% higher average price.

Compared to Q2 last year, total operating costs were 13.7% higher and total capital expenditure was 26.2% lower.

Meridian Energy monthly operating report for December 2025

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