Linked here is Meridian Energy Limited's monthly operating report for the month of May 2025.
Key points this month include:
- In the month to 9 June 2025, national hydro storage increased from 88% to 94% of historical average
- South Island storage increased to 88% of average and North Island storage increased to 138% of average by 9 June 2025
- Meridian’s May 2025 monthly total inflows were 106% of historical average
- Waiau catchment inflows in May 2025 were 123% of historical average
- Meridian’s Waitaki catchment water storage at the end of May 2025 was 84% of historical average
- Water storage in Meridian’s Waiau catchment was 118% of average at the end of May 2025
- May 2025 was another warm month, with temperatures well above average for most of the country. Rainfall was mixed across both islands, with much of the South Island below normal levels.
- National electricity demand in May 2025 was 6.1% lower than May 2024, which was a notably cold month
- New Zealand Aluminium Smelter’s average load during May 2025 was 523MW
- Meridian’s retail sales volumes in May 2025 were 0.7% higher than May 2024
- Compared to May 2024, segment sales in residential were 4.4% lower, small medium business 0.2% higher, large business 10.5% higher, agriculture 8.1% lower and corporate 3.8% higher
Weekly lake storage updates are available on Meridian’s website. See comparative lake levels at: www.meridianenergy.co.nz/power-stations/lake-levels