Physicists meeting in Sydney today will push the Federal Government to support an international project to create fusion power.

The International Thermonuclear Experimental Reactor is being built in the south of France and has the ambitious goal of turning 50 megawatts of power into 500 megawatts - enough to keep the lights on in more than 100,000 homes.

In a fusion reaction, which occurs naturally in stars, two or more lighter atomic nuclei fuse together into a larger one, releasing huge amounts of energy in the process.

It differs from the fission that takes place in nuclear reactors, in that fission splits larger atomic nuclei into smaller ones.

ARC Future fellow Doctor Matthew Hole, from the Australian National University (ANU), will discuss the idea of fusion power as an alternative to coal-fired power stations at the 20th Australian Institute of Physics Conference in Sydney today.

He says Australia could invest as little as $20 million in the $19 billion reactor project, which has investors from the likes of the EU, US, Russia, China and India.

"I liken fusion to trying to light a fire when it's raining," he said.

"It's quite difficult to get it blazing, but when you do get it blazing, you can stand back and watch the power come straight out. But you have to put in a fair amount of power to initiate the experiment."

Dr Hole says the final demonstration power plant will hopefully provide a gigawatt of power, but is not expected to be built until 2040 or later.

"We are talking lengthy time scales, but it should be put in context that the time scale for the development of a base load power plant is at least 10 years even based on existing technology," he said.

"So big base load power is not something you can turn on overnight. It takes time."

Dr Hole says the goal is for fusion power to replace coal.

He says one unit reaction of coal produces about 30 EV (electron volts), while a fusion reaction produces around 17.6 million EV per unit reaction.

"You're talking about millions of times more power than coal," he said.

$20 million investment

Dr Hole says he will tell the Sydney conference that the Federal Government should not only continue to invest in local experiments, but begin to invest in the French-based project.

"We have a proposal that we will be putting forward to the Australian Government soon which could see an Australian sustainable activity in fusion for as little as $20 million," he said.

Dr Hole says $20 million is unlikely to secure intellectual property for the Australian Government, but the Government should none-the-less invest to help create new industries.

"What we're suggesting is that Australia needs to have a sustained capability into the future," he said.

"Looking at it from the point of view of an intellectual capability is very narrow. One has to look at it in terms of how does one create new industries, how does one create new technology, how does on ultimately produce value adding to Australian exports.

"The way to do this is to participate intelligently in high technology experiments, in high technology science."