Power plant owners could make profits of up to 20 per cent on electricity sales when the all-Ireland energy market is introduced next month, one industry figure says.

A single energy market (SEM) for the island of Ireland will be launched on November 1st in a move designed to boost competition, cut electricity prices and guarantee security of supply.

Mark Ennis, an executive with wind energy company, Airtricity, said yesterday that his company estimates that some gas-fired electricity plants will make margins of up to 20 per cent on their sales.

He said that the pricing system that the SEM will use includes a number of incentives designed to encourage investment in generating facilities. These will also benefit alternative energy players such as Airtricity, who will make up to 8 per cent.

Mr Ennis, who spoke at the Eirgrid customer conference yesterday, argued that the policies of the Republic's energy regulator would leave the State overly dependent on natural gas, a fossil fuel, and leave it unable to meet Government targets for renewable energy and carbon reduction. He pointed out that this target calls for a 3 per cent a-year cut in carbon emissions after 2010.

"But if do we keep doing what we're doing, there will be a 30 million tonne gap between where we will be and where we should be," he said. Mr Ennis yesterday called for a temporary halt to the development of new gas-fired generating plants until the Government publishes a clear energy policy outlining how it is going to meet its targets. The island will need around 10,000 mw of wind, or some other form of renewable generation to meet the carbon emission targets.