Mercury's hydro generation for the first half of the 2025 financial year was 3,410 gigawatt hours (GWh), the fourth lowest from the Waikato scheme since 1980.
The company attributed the lower generation to 12th percentile Waikato catchment inflows and a lower than average Lake Taupō starting level.
This, along with lower wind and geothermal generation, resulted in a total generation of 7,906GWh, 11% lower than the previous corresponding period.
However, Mercury's average annual hydro generation has increased to 4,140GWh per annum, driven by the Karāpiro Rehabilitation Project and the Digital River, its AI-powered decision platform.
The full replacement of the third generating unit at the Karāpiro hydro station is expected to be completed in September 2025.
See more
