Key Points:

New Zealand and Australia are about to turn off the incandescent lights that have illuminated them since the bulb was invented more than 120 years ago.

Australian Environment Minister Malcolm Turnbull yesterday announced that traditional light bulbs would be phased out within three years - a move he said would be a world first.

Under law, the super-cheap lighting will vanish from supermarket shelves by 2010, replaced by energy-efficient alternatives such as compact fluorescent bulbs.

Mr Turnbull estimated the move would slash Australia's greenhouse gas emissions by about 8000 tonnes a year in the five years to 2012.

In Wellington, Climate Change Minister David Parker said New Zealand was likely to implement similar measures.

"The Australians are talking about looking at banning ordinary lightbulbs in three years' time.

"Of course new-technology lightbulbs are cost-effective - as well as reducing emissions, they only use about a fifth of the electricity - and I expect in the next couple of years we will be considering those sorts of measures but I don't think there will be an immediate ban."

The timeframe would be similar.

"I think by the time that is implemented in Australia - if it is - we will be doing something very similar."

Energy-efficient lightbulbs come in several shapes including rectangular, spiral and global.

There is no filament to burn through like standard bulbs. Instead they contain gas, which glows inside.

They last eight times longer and use about a fifth of the power.

They cost between about $4 and $7, compared with standard lightbulbs that sell for about $1.

Greens co-leader Jeanette Fitzsimons, the Government's energy efficiency spokeswoman, said New Zealand would set a minimum performance standard for lightbulbs.

Ms Fitzsimons said she had the authority to get the Government's Energy Efficiency and Conservation Authority to look at the issue and she would ask it to do so.

"The small additional cost for compact fluorescence compared with incandescent bulbs pays for itself easily over the life of the bulbs, even if you don't count the cost of having to constantly change them, because they last much longer."

In Australia, lighting accounts for 12 per cent of domestic greenhouse gas emissions and 25 per cent of public sector emissions.

Mr Turnbull said phasing out the traditional bulbs could rapidly reduce emissions by 2015 and save a great deal of electricity.

"These are not small bikkies. These are big bikkies."

If all 60,000 households in Waitakere City replaced five standard 100W bulbs with five 20W compact fluorescent lights, the electricity saved would be equivalent to the annual electricity usage of 3504 households.