Energy Minister David Parker and government spokesperson on energy efficiency and conservation Jeanette Fitzsimons said the days of the traditional energy-hungry incandescent bulb were numbered.
"The traditional light bulb is very old technology - and very inefficient," Mr Parker said.
"Only five percent of the energy it uses generates light - the rest is wasted as heat."
[comment caption=What do you think of the plan to replace old-style bulbs?]The strategy aimed to phase out the bulbs from late 2009. Once new standards were introduced, no new stocks of the incandescent bulbs could be imported for sale.
The Efficient Lighting Strategy was developed by the lighting industry, the Energy Efficiency and Conservation Authority, and the Electricity Commission.
It aimed to achieve the 20 percent goal through more efficient lighting, phasing out inefficient products and setting minimum energy performance standards.
Ms Fitzsimons said technological advances in the area meant there were more and more options.
Some are Electricity Commission subsidised.
New Zealand spent about $660 million on electricity for lighting a year generating about 2.65 million tonnes of greenhouse gas emissions.
Almost $500m could be saved by 2020, "just by changing the lights", Ms Fitzsimons said.
