Meridian Energy - the country’s largest power generator - has reported strong earnings in the June year, but warns the year ahead looks challenging.

The partially state-owned company’s net profit went from $95 million to $429 million - with much of the increase influenced significantly by net gains on hedge instruments of $249 million.

Meridian CEO Neal Barclay says earnings will likely drop in the coming months - and the company has invested more money to ensure there's a steady supply. 

LISTEN ABOVE