Genesis Energy is being criticised for big rises in its fixed daily electricity charge to many Wellington customers, reducing users' ability to cut their bill by saving power.
Genesis is lifting its fixed daily charge for high users in Wellington by 37 per cent to near $1.08 aday from late next month.
Spokesman Richard Gordon said those users would have decreases in their variable rates - the other component in a power bill - meaning their overall power bill would rise by around 4 per cent.
It had been possible to hold the increase to that level because lines charges in the area had gone down because of a settlement between the Commerce Commission and Vector, Gordon told Radio New Zealand.
Low users in Wellington would also have an overall increase of around 4 per cent, although their daily fixed charge would be unchanged at 37c a day.
Consumers Institute chief executive Sue Chetwin said rises to fixed charges limited users' ability to reduce their power bill.
"Saving power in your own home is going to make no difference to the daily fixed charge that you have to pay," she said.
Questions needed to be asked about the electricity industry because of the number and size of price rises in the sector.
The industry was supposed to be competitive, but the market was working only to "a very low degree".
Latest data puts the annual rise in the consumers price index at 1.8 per cent, but Gordon said Genesis' costs were going up ahead of inflation.
