The cost of so-called "poles and wires" utility infrastructure has been the biggest driver of electricity prices over the past five years, the Australian Energy Regulator has confirmed.
Network costs now make up almost half of residential electricity bills while wholesale electricity prices account for another third.
The AER's State of the Energy Market report for 2012 said some factors driving network charges up were unavoidable, but there were also cost pressures difficult for electricity companies to justify.
"The recent overhaul of the rules for setting network charges mean that future network price reviews will ensure energy users pay no more than necessary for an efficient and reliable energy supply," AER chairman Andrew Reeves said.
Costs attributed to the introduction of the carbon tax on July 1 made up eight per cent of a typical bill, while other green schemes such as the renewable energy target accounted for five per cent.
Mr Reeves said one emerging concern was "disorderly bidding" in the wholesale market - when generators making bids without reference to their underlying generation costs.
Mr Reeves also said gas prices were likely to rise in the next few years due to the pressure from international sales and the possibility of restricted supply in the country's east from 2016.
