Consumers are being urged to shop around after energy companies moved to increase gas and electricity prices next year in anticipation of the Hazelwood power station closure.

The move, consumer advocates say, could see the average residential energy bill surge by more than $300 a year.

St Vincent de Paul Society spokesman Gavin Dufty said the price hike was a double whammy as most Victorians were using both gas and electricity in their homes.

"The price rises that are occurring now are quite unique," Mr Dufty said.

"We have had Hazelwood shut down, so there is a lot of base load generation exiting the market and that will lead to increases in electricity prices, which the government has modelled."

However, he said while some retailers had kept the price rise close to the government's predicted figures, others appeared to have put the prices up more than that.

Mr Dufty said the jump in electricity prices for the major retailers ranged between 6.5 per cent to 11.5 per cent. For gas, it ranged from a 5.2 per cent increase to 9.2 per cent.

"The spread for an all-electrical household - for most houses that are not solar - is between a $100 to $200 a year extra," he said.

"For ...people with dual fuel, which is gas and electricity, the spread for most people is between about $200 to $300 a year ...it could be more."

But consumers won't feel the full impact until winter and should prepare themselves for the coming pain.

"All households will experience price increases and some more so than others," Mr Dufty said.

"Householders with solar, and people that have very low bills will see less of a price increase."

Mr Dufty said consumers should compare prices and pressure their energy company to offer a better deal.

"Squeeze the company you are with," he said.

"Make sure you get your concessions ...that's a big discount."

Mr Dufty said a recent Victorian state government reform ensured that for the first time all retailers had to put up their prices on the same day which he said was a good thing.

"Prices were going to go up because of Hazelwood, but at least there is a little bit of competition and transparency."

Energy Australia residential customers who are on its standing offer tariff, using 4.3MW of electricity could see an increase in prices by 9.8 per cent annually, while gas bills will be up by 6.1 per cent.

Origin's residential electricity clients are up for a 6.5 per cent hike and are looking at a 7.8 per cent surge in gas prices.

Experts warn the closure of Australia's cheapest electricity generator in Victoria could see power prices rise in nearby states.

Victoria has been a net exporter of power, so South Australia, NSW and Tasmania will have to find other sources of energy to make up for the loss of Hazelwood.

"I would expect some flow through of wholesale price rises in Victoria after Hazelwood's closure to be reflected elsewhere," energy market expert Bruce Mountain said.

A spokesman for the Australian Energy Council also said power prices could rise in states that relied on Victorian imports.

Even though the cost of producing power hasn't risen, energy producers are charging retail companies 20 per cent more for future contracts because Hazelwood's cheap competition will be gone.

"If you look at the wholesale market prices, (on) what basis do they justify these increases?" Mr Mountain queried.

Mr Mountain authored a Victorian government report that predicted prices would rise between four per cent and eight per cent after Hazelwood's closure.

But AGL said increases in the wholesale energy price meant residential customers on standing offers will see their bills jump 9.9 per cent in 2017.

Australian Energy Council chief executive Matthew Warren said the Hazelwood closure was interrupting a downward trend on standing offer prices, which cover about 10 per cent of Victorians.

"Last year, standing offer electricity prices fell 1.9 per cent and that followed a drop of 3.6 per cent in the prior year," Mr Warren said.

Energy Minister Lily D'Ambrosio said the government would come down hard on energy companies that price gouge.

"Every Victorian, when they get home, should get on the phone, demand a better price from your retailer," Ms D'Ambrosio said.

"If you don't like the answer that you get, shop around."

Opposition energy spokesman David Southwick said the government had lied to Victorians about the impact of Hazelwood's closure.

Victoria announced this week that former MPs John Thwaites and Terry Mulder will lead a review of retail power prices and how to improve the market.