(Image: Mitchell Squire/Private Media)

Angus Taylor's proposed "CoalKeeper" tax on electricity bills could significantly outstrip the impact of the Gillard government's carbon price, forcing up household electricity prices by at least 14%.

The tax, which would pay to subsidise the Coalition's fossil fuel donors to keep uncommercial coal and gas-fired power plants operating even if the electricity they produce is unused, has been estimated by the Institute for Energy Economics and Financial Analysis to cost between $2.9-6.9 billion. That would mean an increase in ordinary household electricity bills of between $182-430 a year.

An additional $182 a year would mean a 13.6% increase in electricity bills in south-east Queensland, based on bill data from the Australian Energy Market Commission (AEMC). It would mean a 14% rise in NSW; 9.3% in the ACT, 16% in Victoria, 9.7% in South Australia and 9.4% in Tasmania. An increase of $400 a year would mean bill increases of more than double those figures. The AEMC has forecast bill reductions in south-east Queensland, Victoria and South Australia this year, suggesting the increases would be proportionately even bigger.