Mercury NZ’s annual profit will be affected by dry weather in 2025, the company says. 

The power generator and retailer said it had revised its earnings before interest, tax, depreciation, amortisation and financial instruments for the year down to $760 million from $820m. 

“This reflects an expected 150 gigawatt hour (GWh) decrease in full-year hydro generation to 3400GWh owing to continued dry weather in the Taupō catchment, and projected below-mean hydro inflows and lake level through to June 30, 2025,” the company said. 

The full-year ordinary dividend guidance remained unchanged at 24 cents a share and its “stay-in-business” capital expenditure guidance was unchanged at $150m. 

In February, the company — 51% owned by the Government — said it expected power prices for its residential customers to rise on average by 9.7% from this month. 

The company said then that energy prices — gas and electricity — for consumers were expected to increase across the board. 

The rise primarily reflected increases in lines and transmission charges due to rising costs and the level of investment in infrastructure required, in line with the Commerce Commission’s price path reset for the next five-year period. 

It also reflected the rise in the cost of wholesale electricity and other costs. 

Mercury’s downgrade follows a challenging 2024 for most of the power generator-retailers, who faced a gas shortage, low hydro inflows and calm wind conditions, which combined to drive power prices to more than $800 per megawatt hour in August. 

Jamie Gray is an Auckland-based journalist covering the financial markets, the primary sector and energy. He joined the Herald in 2011.