QUEENSLAND households will be penalised with higher power prices for keeping their air-conditioners off over summer.

The state's electricity price regulator, the Queensland Competition Authority, has announced a 6.6 per cent increase in power prices from July 1.

The increase will add $120 to the average bill of households already under pressure from an array of cost increases.

Power prices have now soared by more than 60 per cent since the State Government promised deregulation of the industry in the southeast would put downward pressure on prices.

Almost 80 per cent of the increase was blamed on growing network costs, the price passed on to consumers for building and maintaining the power system to cope with increasing demand.

However, lower than expected power consumption over the disaster-affected summer meant distributors did not recoup their investment costs.

Those costs have now been attached to electricity prices for 2011-12, meaning households will pay extra for not using enough power this financial year. "Between 2009 and 2010 the load decreased by 2.13 per cent, reflecting the more benign temperatures during the latter months of 2010," the QCA said in a statement.

"As costs increased while the load decreased, the (electricity price) was pushed higher than it would have been had the load remained relatively constant."

Energy Minister Stephen Robertson described the outcome as "perverse" but said consumers would benefit in years when they used more power than predicted.

"As perverse as it sounds there has been a slight upward adjustment to take into account the mild summer," he said.

"But next year we could have a very hot summer and the reverse would apply under those circumstances."

He said the increase "could have been far worse".

"For an average electricity user, an average family in Queensland, it represents a further increase of around about $29.40 to the average quarterly bill," he said.

The QCA said the electricity price increase for 2011-12 would have been 8.31 per cent if the damage from floods and cyclone experienced by distributors was passed on to consumers.

However, the Government last week announced it would prevent Ergon and Energex from recouping the costs of rebuilding its network.

The authority also found the Federal Government's Renewable Energy Target, which will require that 20 per cent of all power be produced from renewable sources by 2020, also contributed to the price increases.

Queensland Council of Social Service president Karyn Walsh said the increase would push more low-income households further into poverty and targeted government assistance was needed.

Originally published as We turn off power, so bills go up