Mighty River Power says sales volumes fell in the last three months of 2013 as residential customers used less electricity in an unusually warm Spring.
The company also continued to shed low-margin commercial customers.
Overall, customer sales volumes fell 9 percent over the quarter, but the prices customers paid Mighty River rose a marginal 0.6 percent.
South Island storage lakes were unseasonally full over the quarter, lowering the national wholesale price of electricity, so Mighty River says it chose to store water at Taupo rather than produce hydro electricity.
