Key Points:

Dimming the lights for a romantic dinner could end the evening with a bang once planned Government lighting regulations kick in.

The Government wants to cut lighting energy consumption by 20 per cent by 2015 and from late next year incandescent lightbulbs will be banished.

Green Party co-leader Jeanette Fitzsimons has hailed the move, saying the changes to compact fluorescent lightbulbs (CFLs) could save the country $500 million by 2020.

But while the changes are likely to benefit the environment and people's pockets, some in the lighting industry are warning of issues people will need to get used to.

"If you try to dim the lights with CFLs you'll probably end up blowing the switch," said Kevin Lord, who manages Hamilton's Lighting Direct store.

"They have developed some you can dim but at the moment they're not on the market and if they are, they don't comply with New Zealand standards."

Mr Lord said things were also not so bright for chandelier lovers as the sharp white light from CFLs could not bring out the sparkle in a chandelier's crystals.

"When you put an opaque-type lamp in it [the chandelier] it's just a dead, dull light.

"I'm not sure what the future option will be."

He said a quick night-time dash to the toilet could also be a problem, with some CFLs taking up to a minute to warm up and fully light an area.

And the future of heat lamps, used in bathrooms and restaurants, was also a "curly one" that would have to be sorted out.

"But overall I think it won't be too big a problem for people and most will probably adapt pretty quickly."

A report from the Efficient Lighting Group showed 8 per cent of the total energy used in homes was consumed by lighting.

The figure increases to 14 per cent in lighting for businesses and public areas.

But CFLs typically use between a fifth and a quarter of the energy an ordinary lightbulb uses while lasting eight to 10 times longer.

A spokesman for the Electricity Commission said an average four-bedroom home, which typically had 28 lightbulbs, could potentially make significant savings on its annual power bill with CFLs.

Based on an electricity unit cost of 20c/kWh, the cost of using a quality 20-watt CFL for four hours a day was less than $5 a year, which compared favourably with the $21.90 to run an ordinary lightbulb.

He said CFLs had minuscule traces of mercury, so the bulbs had to be carefully disposed of if broken, but the amount was about a hundredth of that contained in the average mercury tooth filling.

Q: How much do they cost?
A: On average about $6, although cheaper, poorer-quality options are available. They can last between 6000 and 15,000 hours.

Q: What do they cost to run?
A: CFLs typically use a fifth of the energy of an ordinary lightbulb. So based on an electricity cost of 20c/kWh, a CFL used 3 hours a day throughout the year will cost $4.40 compared with $21.90 for a standard bulb - a saving of $17.50 per year per bulb.

Q: Do you need to change your light fittings to use them?
A: No. CFLs come in screw and standard bayonet types so can be fitted in place of standard incandescent bulbs.

(from the Energy Efficiency and Conservation Authority website and the Electricity Commission)