Types of efficient light bulbs

There's a range of types, shapes, of shades energy efficient light bulbs that work in most kinds of fittings. These include compact fluorescent lights (CFLs), new generation halogens, and light emitting diodes (LEDs).

Make sure you're getting the right light for the job. You might need to choose a bulb that works with dimmers, or need a specific brightness or to suit a particular shaped fitting.

Compact fluorescent lights (CFLs) are suitable for general household and mood lighting, for example. Halogens, on the other hand, are well suited to task lighting where sharp visual clarity is required. Halogens work with dimmers and sensors, and fit into traditional fittings.

Efficient lighting may cost you more to buy, but saves you money on running costs and power bills. Also check out the latest subsidies available on efficient light bulbs offered by the Electricity Commission.

These are the main types of efficient lighting currently available in New Zealand:

New generation halogens

Compact fluorescent lamps (CFLs)

Straight/circular fluorescent tubes

Light emitting diode (LED) lights

New generation halogens

New generation halogen

New generation halogen bulbs fit into traditional fittings and work well with dimmers and sensors. They're also suitable for short switching cycles.

These are the bulbs for task lighting where good colour definition or visual clarity is required - such as make-up application, hobby work or reading. They work well for accenting, too.

New generation halogen bulbs are readily available in lighting shops.

Compact fluorescent lamps (CFLs)

Standard CFL

Covered CFL

CFLs are the most well known type of efficient light bulb and are good for general household lighting. They come as standard spiral bulbs, and covered bulbs.

They are very efficient. Good ones use around 75% less electricity than a traditional incandescent bulb. A good quality CFL lasts from 6,000 to 15,000 hours, whereas the older traditional incandescent light bulb typically last about 900-1000 hours. Check the box to find out the expected life of the bulb.

Range of CFLs

CFLs come in an increasingly wide range of shapes, colours, and sizes. They have both screw and standard bayonet fittings and can be fitted in place of standard incandescent bulbs in many situations. Some can be used with dimmers or in downlights. Check the box before you buy, and consult a professional if you're unsure.

CFLs are available in a range of shades including warm white and cool white. Warm white is closer to the colour from a standard incandescent bulb. Whereas cool white has a bluish tinge. Some people prefer cool white lights where contrast is preferred - for reading or in bathrooms, for example.

CFLs end of life

CFLs contain complex electronic circuitry. Sometimes, when they reach the end of their life, they behave differently from traditional light bulbs. This normally shows simply as a change in illumination of the lamp - such as flickering or dimming. However, other effects can occur. These are normal and not considered a fire or safety hazard. They include:

• A distinctive odour or a small amount of smoke coming from the base of the bulb
• Discolouration (browning) or slight charring (blackening) of the base of the bulb
• The fire retardent plastic of the base deforming or opening slightly.

If any of these things happen or if your bulb is losing brightness or starting to flicker, it's time to replace the bulb. Switch the light off, let the bulb cool down, and remove it.

Mercury in CFLs

CFLs contain a small amount of mercury (between 2 and 5 milligrams). This is enough to cover the head of a pin. There's about 100 times more mercury in the old style household thermometer than there is in a CFL.

Mercury is a toxin. A broken CFL should be disposed of responsibly.

The Ministry for the Environment has developed guidelines for safe disposal of CFLs. This work is ongoing and is a focus of the energy efficient lighting and product stewardship work programmes. The Ministry for the Environment website has more information on the product stewardship work programme.

Disposal of CFLs

Your local council or lighting supplier may provide a light bulb recycling programme or HazMobile collection service.

However, if you need to throw CFLs away, wrap them in newspaper, put them into a plastic bag and place in the rubbish.

Broken CFLs

The levels of mercury which may be made available from the breakage of a CFL should not constitute a health risk. However when clean up of a broken CFL is required, follow the Ministry for the Environment's guidelines for safe disposal of CFLs.

In summary, the advice is:

Use rubber or latex gloves

 To protect yourself from being cut by broken glass while cleaning up.

Ventilate the room before you start the clean-up

• Mercury vaporises readily at room temperature. Open all windows and leave the room for at least 15 minutes. Don't walk over the affected area. Turn off heating/air conditioning systems, heat pumps, dehumidifiers and ventilation systems.
• Carefully sweep all the big pieces of glass. Use stiff paper or cardboard. Wrap the gathered pieces in newspaper and place in a plastic bag.
• Use the sticky side of any thick tape to clean up all the small pieces. Duct tape is ideal. Wrap the used tape in newspaper and place in a plastic bag.
• Don't use a vacuum cleaner or a broom to clean up a broken light bulb. This will vaporise and spread mercury through the air and contaminate the vacuum cleaner or broom.
• Wipe the area down with a damp paper towel. Place used paper towels in a plastic bag.
• Remove rubber gloves and place in a plastic bag.
• Wash your face, hands and arms thoroughly, and change your clothing after cleaning up.
• Seal all the plastic bags containing the broken pieces of the light bulb, paper towels and rubber gloves used in cleaning up. Dispose of them with the household rubbish. Store outside until the next collection.

Straight/circular fluorescent tubes

Circular fluorescent tube

Fluorescent tube

These use the same technology as CFLs so they are also very long lasting and efficient.

Light emitting diode (LED) light

LED light

These are efficient and can last up to 50 years - though they're relatively expensive to buy. They're good for guidance and effects - strip-lighing in hallways, step lighting and outdoors, for example, or tree up-lighting.

More information

• Visit the Rightlight website for comprehensive information about lighting
• The safe use and disposal of household lamps [Ministry for the Environment website]
• Light Years Ahead - efficient lighting guide 
• CONSUMER energy efficient lighting guide
• Ministry for the Environment's stewardship programme
• HazMobile collection service