Announcing the Liberals' energy policy yesterday, opposition treasury spokesman Peter Gutwein said the state- owned energy businesses needed to focus on assisting business growth in Tasmania, rather than serving as "cash cows" for the state government.

Tasmania's major industrial consumers, including Bell Bay Aluminium and Grange Resources, have suffered about a 200 per cent increase in transmission costs over the past five years, prompting the Liberal promise to review electricity charges.

The Liberals would form an energy working group to work on a state energy strategy due to be finalised by the end of the year.

"Taking cost pressures off business in Tasmania in regards to electricity prices is going to be on the table," Mr Gutwein said.

This financial year, it's estimated the state's three energy businesses will pump $287 million into state coffers through dividends and tax equivalents.

Deputy Premier Bryan Green warned subsidising electricity costs for major industry would blow a big hole in the state budget or force power prices up for households.

"Even a 10 per cent reduction in dividends and returns from our energy businesses would rip $70million out of the pockets of Tasmanians and into the profits of BHP and Rio Tinto," Mr Green said.

However, Mr Gutwein said it was possible to do both.

"If the GBEs [government business enterprises] have more customers that are utilising power then dividends will take care of themselves," he said.

Bell Bay Aluminium general manager Ray Mostogl said energy prices accounted for 35 per cent of his company's costs - a figure he hoped would go down as a result of the review.

"We do believe that the little bit of private wealth generation that is still coming on in the state is at risk," Mr Mostogl said.

"We think there is an opportunity to optimise the provision of that energy and still pay a dividend and bring prices down."

Norkse Skog general manager Rod Bender recognised it was a complex problem, but government had to tackle it.

"At the end of the day this has fundamentally got to reduce cost pressures on Tasmanians," Mr Bender said.