The drought last autumn and early this winter was costly for the electricity industry.
The biggest company, Meridian Energy, has announced its profit for the year to June halved compared with the previous year.
Its profit was $128.6 million for the year to June, compared to the previous year's profit of $241 million.
The oil-fired Whirinaki power plant, which is used as reserve generation plant, failed to keep a lid on power prices as diesel prices rose sharply.
Spot power prices rose sixfold to peak to almost $400 a megawatt hour in June.
However, Meridian still paid the Government a total dividend of almost $236 million for the year.
The national grid operator Transpower also experienced a fall in profit, in part due to costs incurred in keeping electricity flowing south during the drought.
Mighty River Power's annual profit rose 15% to $111 million despite the worst drought to hit the Waikato River for 80 years.
The drought meant hydro volumes dropped 9%, though this was offset by Mighty River Power's gas-fired Southdown plant.
Thermal generator Genesis Energy boosted its profit by 12% to $99.1 million as its coal-fired Huntly plant and gas-fired e3p plant made up a shortfall from hydro sources.