Pressure on electricity supplies will grow unless a way is found to control telecommunications' energy appetite.

The internet, we're often told, will help to spread democracy to the far corners of the world, effect a cure for cancer and stop climate change in its tracks.

While the first two might one day be true, research suggests the last is unlikely, at least on present trends. In fact, the way internet use is going, it will end up contributing to global warming.

That prediction is based on the work of Melbourne University professor Rod Tucker, who calculates that in Australia, telecommunications services - of which the internet is an increasingly big part - account for about 0.5 per cent of electricity use. The New Zealand figure would be similar, says Tucker, who concedes it's not a large number.

Not yet, maybe. But because internet electricity consumption is proportional to the amount of data whizzing around, the figure won't stay small for long. With internet traffic expanding at a rate of about 40 per cent a year, within a decade the net could be burning about 15 per cent of the world's energy.

Unless savings are made elsewhere, the internet is therefore set to add to the pressure on electricity supplies.

Not only that, says Tucker, a telecommunications engineer before joining the university. Electricity, he says, is also an increasing cost on internet service providers (ISPs) that will inevitably be passed on to users.

It's that which could spur ISPs, telcos and equipment suppliers to do something about it. More than a dozen of them, including AT&T, Bell Labs, Huawei, several European telcos and research institutes at MIT, Stanford and Melbourne universities, have formed GreenTouch, which is aimed at making telecoms networks more efficient.

"It needs people from across the whole industry to be involved," says Tucker, a founder of the global consortium. Australian and New Zealand service providers haven't signed up to the initiative but Tucker says he is working on them.

If you're wondering where all the electricity is going, think about your own consumption. New Zealand has about a million broadband internet connections, all of which require some sort of device in homes and offices to attach users' computers to the service provider's network.

Typically these devices, generically called modems, use about 10W of power, about the same as an energy-efficient light bulb. And typically, also, they're on day and night.

A million of these gadgets will chew through 10MW of electricity, about the capacity of a small commercial hydro-power scheme. Turn them off for the 90 per cent of the time they're not in use and considerable savings can be made.

At the service provider end of the network, the waste is even greater. Historically, Tucker says, telcos and ISPs have expanded their exchanges and data centres to meet growing demand without a thought for limiting energy use.

"You'd just bring a truck in with more equipment, plug it in and away you go. It turns out a lot of equipment is not being used very efficiently or effectively."

It's not as simple to turn equipment off in exchanges and data centres as it is in homes and offices, Tucker says, since it has to cope with traffic going in countless directions non-stop. Imagine sitting in a control room flicking switches as different parts of the network go from busy to quiet and back again in the blink of an eye.

Humans simply aren't up to the task. But equipment-makers are devising ways in which network gear can dynamically turn on and off depending on load.

"There are ways of making the equipment more intelligent so that in slow periods certain pieces of equipment are switched off and the data is channelled elsewhere."

Savings of 50 per cent to 75 per cent are thought to be achievable that way. The good news is the same capability will eventually be standard on home equipment, sparing us the hassle of turning modems off and on.

There's more good news, too. Like computers, the electronic innards of network equipment follow Moore's law, which roughly means they double in efficiency every couple of years.

And before the internet is demonised as a cause rather than a cure of global warming, the part it can play in curbing greenhouse gas emissions should be acknowledged. Using the internet, telecommuters and videoconferencers, for example, drive and fly less.

GreenTouch, meanwhile, has set an ambitious target to hasten the development of power-saving network equipment. It is aiming for a 1000-fold efficiency improvement by 2020, Tucker says.

"Consumption might go from half a per cent to 1 or 2 per cent but, I think what our research is showing is that, if we do things intelligently, the growth of energy use in the network can be held in control."

Anthony Doesburg is an Auckland technology journalist