Demand for electricity is continuing to grow, new figures show, although a new energy reduction scheme has slowed the rate of growth.

New figures show that peak demand for electricity, which usually occurs in January or February was 4,434 megawatts in 2004, but rose this year to 4,528 megawatts.

However, ESB National Grid managed to reduce the rate of growth by operating an energy efficiency scheme. The scheme involves major industrial customers reducing their usage during peak hours.

A spokesman said there was a major increase in the numbers of customers participating in what is known as the winter peak demand reduction scheme. The total amount that large Irish businesses could save this coming winter could rise to over €6 million if more businesses took part in this scheme, said a spokesman.

"Reductions in overall daily demand of up to 100 megawatts for electricity at peak hours were achieved during the scheme last winter - equivalent to one million 100 watt light bulbs being switched off at the same time," he added.

The scheme financially rewards companies that reduce their electricity consumption during peak demand hours , between 5pm and 7pm, in winter months.

The number of companies taking part increased from 186 in winter 2003/04 to 236 in the winter 2004/05. The scheme is available to all large electricity customers and is run in liaison with all the electricity supply companies operating in the market.

"In addition to providing savings for the participating customers, the scheme has brought national economic and environmental benefits since lower demand at the peak period reduces the need for less efficient forms of power generation," said a statement.

This is the scheme's third year of operation. Total rebate payments to customers were €4.1 million not including the savings customers gained by reducing the amount of power they used.

ESB National Grid is Ireland's transmission system operator. It does not sell power but transports it around Ireland on the high-voltage electricity system.

The Commission for Energy Regulation (CER) two years ago awarded contracts to companies to build two new power plants. The contracts were won by Aughinish Alumina in Co Limerick and Tynagh Energy in Co Galway.

Both plants are currently being built and will come into operation early next year.