AGL power prices to rise in SA

South Australian Energy Minister Tom Koutsantonis has urged AGL customers in the state to consider switching to a rival electricity and gas supplier after the company announced big price hikes.

AGL's electricity prices in SA will rise by 18 per cent from July, costing the average household an extra $350 a year.

Gas prices are also set to increase, but Mr Koutsantonis says consumers can save hundreds of dollars by switching to a rival supplier.

"Time for movement," Mr Koutsantonis tweeted on Friday.

AGL pointed to rising wholesale prices as the reason for its retail increases.

"Wholesale prices have increased for a number of reasons, including high gas prices and limited gas availability on the east coast, the closure of ageing coal-fired generators, and an uncertain policy environment," the company said in a statement.

"Any decision by AGL to change prices is based on a detailed consideration of a range of factors including costs, market conditions and the value we offer customers."

Mr Koutsantonis said the prices hikes were unsustainable and highlighted the need for urgent reform in the electricity market.