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Find the best energy-efficient bulbs for your home.

CFL and LED bulbs are a green form of lighting, but do they last the distance? We've tested both types of bulbs, and look at how much you could save by changing from old-style incandescents.

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From our test

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Our CFLs test

We bought 19 CFLs. 14 were rated 20W, 4 were 18W and 1 was 19W. All were (2700K) warm white.

The CFLs were mainly spiral tubes but there were also 3 “stick” (U-tube) types. The spiral shape has largely taken over the home-CFL market because in most fittings it gives a more even distribution of light.

This is the third time we've tested CFLs. In all 3 tests we’ve found that good-quality CFLs are brighter, last far longer and use much less electricity than old-school incandescent bulbs. This test’s findings were no different … although our results also show a wide variation in performance between CFLs.

Light output

We wanted to see if the CFLs were as “bright” as the bulbs they replaced. So we put 2 samples of all the CFLs into a special test rig and compared the total light output of each model with the averaged light output from 5 100W incandescent bulbs of different brands. This “incandescent average” figure formed our baseline – and the relative light output of each CFL shows its performance against the baseline.

The light output of almost all the bulbs in our test was satisfactory – only 4 produced less light than our “incandescent average” baseline.

The GE Entice had the highest light output – 46 percent brighter than our baseline. It was followed by the Envirolux (37 percent brighter) and the GE Tiny Spiral (34 percent brighter).

Warm-up time

When they're switched on, it takes a while for CFLs to warm up to full brightness. We tracked the light output of the bulbs, noting how long they took to reach 90 percent of their maximum brightness.

The best models took 15 seconds and the slowest 2½ minutes to reach 90 percent of their maximum brightness.

How much the warm-up time matters depends on where the CFL is being used. For a hallway light that's switched on once a day and stays on, it doesn't matter. But where the light will be switched on often – such as in a pantry or toilet – the delay could be really annoying.

Long life

We put 3 samples of each of the CFLs into a rig which switched them on for 5 minutes then off for 5 minutes. It did this 6000 times – more than 2 months of on-off cycling which equates to about 7 years average use. The bulbs were continuously monitored so that we could tell if and when they failed.

11 models had no failures during the 6000 on-off cycles.

A $6.50 20W CFL running an average of 3 hours per day will pay for itself in less than 4 months. The longer the CFL lasts, the more you save.

MEPS and Energy Star In October 2012 minimum energy performance standards (MEPS) for CFLs were introduced. Because old stock is allowed to be run out, our test had a mixture of older CFL bulbs and the new MEPS-compliant models.

Energy Star qualified bulbs (with the blue Energy Star mark) are the most energy-efficient available – and this translates to lower running costs. 3 of our test bulbs were Energy Star models.

Our LEDs test

For this test we chose 2 types of readily available LED bulbs.

The first type was GLS (general lighting service) bulbs in 6.5-8 and 10-11 watt sizes. These are equivalent in light output to 40-60W old-school incandescent bulbs. One of the LED bulbs was dimmable.

The second type was MR16 (50mm diameter) bulbs for spotlights. These were further divided into 230-volt units (GU10 base) and 12-volt units (GU5.3 base) – both of which are replacements for 35-50W halogen spots. One of the 12-volt bulbs was dimmable.

We tested 3 of each bulb and averaged the test results for each.

Light output

To test if the light output of the LEDs was as good as incandescent bulbs and halogen spots, we measured the light output of five incandescent 40W bulbs and averaged the results. We did the same for 5 60W and 75W incandescent bulbs. We then followed a similar procedure for the halogen spotlights.

Once these baselines were established we compared each LED bulb with its incandescent or halogen equivalent.

The model-to-model light outputs varied substantially. The GLS LED bulbs were all “brighter” than their incandescent counterparts and the Panasonic LDAHV8L27H2 had over twice the light output.

The spotlights were different – only 2 of the 12-volt LED bulbs had a higher light output than their equivalent halogen spots. The rest of the LED bulbs, both 230 and 12 volt, were disappointing. The lighting industry has more work to do to make these LEDs a true drop-in replacement for halogen spots.

Long life

An incandescent bulb lasts for around 1000 hours, a CFL for around 5000 to 8000 hours, but LEDs are often stated to have a life of 20,000 hours or more. We simply can’t test for that long. User experience will tell if those life claims are correct.

LEDs run much cooler than incandescent bulbs. But that’s not the end of the story. LEDs have electronic components in the base of the bulb – and if these components (or the LED chip itself) get too hot (over 60°C), the light output decreases and the bulb may fail early on.

LEDs should only be installed into ventilated fittings where air can move through the fitting. Where LEDs don’t last the distance, the most likely culprit is heat – they don’t like getting too warm.

To get some idea of whether the LED bulbs would last, we put three examples of each bulb in a special test rig that (under computer control) switched them on and then off 12,000 times. There were no failures.

When we last tested CFL bulbs in 2013 using the same rig but only 6000 on-off switching cycles, 18 of our 60 CFLs failed during this test.


An LED bulb can pay for itself with the savings it makes in electricity consumption. Running a 60W incandescent bulb for 4 hours per day would cost nearly $22 a year. The equivalent 10W LED would cost less than $4. And the LED should continue to make those savings for many years.

Likewise a ceiling full of 35W halogen spotlights (12 bulbs) running for 4 hours per day would cost $153 a year to run. 12 6W LED equivalents would cost just over $26 to run.

Which light where?

Good interior lighting can create various moods, highlight your interior décor, and provide good light - without burning up the power bill.

The days of a light bulb starkly hanging on a cord in the centre of a room are long gone. Nowadays you have a vast choice of lighting products, increasingly using various energy-efficient lighting technologies. But which products work best - in what parts of the house?

The lighting requirements of the rooms in our houses vary - depending on what the room is used for. Different light levels are required in various parts of the house – and even within some rooms. The colour of the light is also important – it can change the mood of a room and can make a difference to dining, reading and other activities.

Choosing the right lighting products can also save money on your power bills.


You need intense light to read or to do close-up tasks, but if you lit your whole lounge to that level the glare would be uncomfortable.

An easier approach would be relatively soft background lighting using ‘warm white’ CFLs or new- generation halogen bulbs to create a relaxing mood. You can also use efficient infa-red coated (IRC) halogen spot lights or reading lamps with CFL or new-generation halogen bulbs to provide the flexibility to set the mood for any occasion.

Hallway and stairs

You need moderate light levels, but lights in these locations are likely to be left on for many hours, especially in winter, so it’s important to use energy-efficient bulbs.

Replace standard incandescent bulbs with CFLs if the lights are likely to be left on for long periods. If the bulbs can be seen and looks are an issue, choose decorative or covered CFLs (if the bulb is hidden by a lampshade, what it looks like doesn’t matter). If the lights are only on for a brief time and instant light is desirable, new-generation halogen bulbs turn on just like a standard bulb but last twice as long and are 30% more efficient.


For a kitchen you need background lighting (brighter than in the lounge) because a higher level of shadow-free light is required – so you can see in the cupboards. Extra task lighting will make sure bench tops, stoves and walk-in pantries are well lit.


A relaxing bath with soft lighting is one of life’s pleasures. But not being able to see to shave or put on make-up is not. You need moderate background lighting, and brighter, directional lighting for mirrors. The light should shine on your face - not on the mirror.

To achieve this blend of a functional yet relaxing space consider using separate switching for different lights or adding a dimmer to the main lighting. There are now efficient bulb replacement options for most bathroom lights and an ever increasing range of stylish fittings designed for both efficiency and good looks.


Outdoor lighting can range from a simple porch light to spot lights for lighting up deck or entertainment areas, or to create dramatic effects for illuminating driveways, paths and garden areas. For lights likely to burn for a long time, use energy-efficient options in suitable outdoor fittings.

Choosing the right energy-efficient bulb

Now that our testing of energy-efficient bulbs has proved their light output and longevity, there's good reason to fit out the whole house.

Good CFLs are just as bright or brighter than the incandescent bulbs they replace.
Good CFLs are just as bright or brighter than the incandescent bulbs they replace.

Research has shown that the average home has 30 light fittings but only 6 are fitted with energy-efficient bulbs.

Lighting costs the average household $220 per year – about 12 percent of its electricity bill. Because lighting demand is higher during winter evenings, improving lighting efficiency reduces the demand on our electricity distribution infrastructure – and lowers your electricity bill.

Our testing has shown that good CFLs are just as bright or brighter than the incandescent bulbs they replace. We also showed that name-brand bulbs last very well when switched on and off frequently.

Although the spiral CFL has become the general-purpose replacement for the traditional incandescent bulb, there are many other available shapes and sizes. This means there’s an energy-efficient option for nearly every bulb in your house.

What types of bulbs are available?

Most energy-efficient lights fall into 3 categories: CFLs, halogens and LEDs.

  • CFLs save you 80 percent of a standard incandescent’s energy costs and they last for thousands of hours. But dimmable CFLs cost more than ordinary CFLs.
  • New-generation halogens save about 30 percent of the energy costs of standard incandescents and last about twice as long. New-generation halogens are compatible with dimmers.
  • LEDs (light emitting diodes) are a much less common type of energy-efficient light. But they’re expensive and their white light has a rather harsh, bluish tinge. The most common use for LEDs is in low-level lighting for hallways and stairs. There seems little doubt that LED lights will become mainstream cost-effective products – but they’re not there yet.

Bulbs for places

Places where the lights are switched often
Our CFL switching test showed that good-quality CFLs could stand being switched on and off repeatedly over more than 8000 on-off cycles. That means good CFLs can be used in walk-in wardrobes, toilets, bathrooms and kitchens – places where the lights are often switched on and off.

Lights with dimmers
There are 2 energy-efficient options here: Dimmable CFLs will save you around 80 percent of a standard incandescent bulb’s energy costs and they last as long as other CFLs. However, they’re still pricey at around $20 each.

New-generation dimmable halogens give a 30 percent energy saving, last twice as long as a conventional bulb and cost about $5 each.

Standard incandescent bulbs in recessed downlight fittings waste a considerable amount of energy, because they let warm air from the living room rise into the roof space. However, reflector bulbs reduce this waste – and they’re more energy efficient. CFL reflector bulbs will save you about 80 percent of a standard bulb’s energy costs; halogen reflector bulbs will save you about 30 percent.

Halogen spotlights
Infra-red coated (IRC) halogen reflector bulbs are more efficient – and they’re dimmable. You’d use a 35W halogen reflector spotlight to replace a standard 50W spotlight.

Exposed bulbs
You don’t like the look of a spiral CFL? It’s possible to get covered CFLs that give a more traditional look.

Decorative bulbs
Energy-efficient bulbs also come in special shapes (such as candles) and smaller sizes (for use in chandeliers and other decorative fittings).

Reading lights
The light produced by incandescent (including halogen) bulbs provides a more comfortable light for reading and other close-up tasks than CFLs and LEDs. Use IRC halogens for reading and other close-up tasks – they’re more efficient than standard incandescents. Switch off the light when it’s not needed.

Where to buy energy-efficient bulbs

For everyday spiral and other common CFL shapes look in your supermarket first. Hardware chains will have a wider range of the more specialised styles but for that even harder-to-get bulb try the specialist lighting shops.

Our advice

  • Take advantage of the increasing range of energy-saving bulbs on the market and fit out as much of your home as possible. They save money and reduce peak loads on the electricity system.
  • As a general rule use CFLs for background lighting and IRC halogen spot lights for reading and other task lighting.

CFL bulb shapes

There’s now a big range of shapes and sizes to suit most domestic uses.

  • Spirals: These give you the most light for the least money. They’re becoming the "universal" CFL. Only use one of the more specialised types if a spiral won't do.
  • U-tubes: The light from u-tube CFLs sprays out sideways – this can suit some fittings, especially if the bulb lies on its side in the fitting.
  • Covered: An exposed spiral CFL isn’t pretty. That might not matter in a covered fitting or in the laundry or garage – but where it does matter you can use a covered CFL. These have a frosted glass globe over the CFL tubes to give a traditional "light bulb" look.
  • Decorative: Small bulbs, round bulbs, candle-shaped bulbs – they’re all available as CFLs and in a variety of base-fitting types and sizes.
  • Reflectors: If you have reflector lamps in recessed downlight fittings, then changing to CFL versions can save heaps. CFL reflector lamps get much less hot than incandescents. That lower heat reduces the heat loss from the room into the roof space (through the downlight fittings). CFL versions of both R63 and R80 reflector lamps are available.
  • Spotlights: Halogen spotlights are often 50W each. So a ceiling full of them is like running a small heater up there. Replacing them with 9W or 11W CFLs will save money. CFL replacements are available for mains-voltage (GU10) halogens but not for the 12-volt versions.
  • Outdoor security or floodlights: These can chew through the power if they’re left running for a long time. CFL versions use one-fifth the power – but aren’t suitable if the lights are controlled by a sensor switch.

LED facts

What you need to know about LED bulbs.

  • You can’t yet buy an LED replacement bulb that’s as bright as a 100W standard incandescent bulb.
  • LEDs cost much less to run than incandescent bulbs of an equivalent light output – and they cost a little less to run than a CFL.
  • LEDs last longer than other bulbs, so they’re useful for those harder-to-reach light fittings.
  • LEDs run much cooler than incandescent bulbs.
  • Some LEDs can be dimmed.
  • LEDs don’t like heat – they operate best when installed in a fitting that allows air circulation.
  • You can buy LEDs from supermarkets, hardware stores and lighting specialty stores.

CFLs and mercury

How safe are broken CFLs?

The introduction of CFLs has seen some emotive claims made about the perceived hazard from the mercury released from a broken bulb. We've looked at an extensive independent study into the health risks, and conclude that the tiny amount of mercury in a broken CFL is unlikely to be a health hazard.

What's the risk?

All CFLs contain very small amounts of mercury (less than 5mg), which is only released if the bulb is broken. The amount of mercury released depends on how used the CFL is – the amount reduces as the bulb ages.

Mercury is particularly toxic to children, pregnant women (and the baby they’re carrying), and people with kidney disease. When mercury vapour enters our bodies, it has a half-life of about 2 months. That is, it takes around 2 months for the mercury level to halve, another 2 months to halve again … and so on.

But how much mercury is toxic? The total amount that enters our bodies is dependent on the combination of the mercury concentration level and the exposure time.

Safe concentration levels have been established by several overseas studies. It varies with the exposure time and for continuous lifetime exposure the concentration level is much lower than for short durations.

The Ministry study

We were planning to do our own testing of the health hazards from broken CFLs – but when we heard in late 2008 of a study being conducted by the Ministry of Health we decided our test would be a waste of resources.

The scenarios

The Ministry’s study looked at 2 broken-CFL scenarios. In the first, mess from the broken bulb wasn’t cleaned up and the room wasn’t ventilated. In the second, the mess was cleared up and the room was ventilated by opening the window.

Mercury vapour concentration levels were measured 15, 30 and 60 minutes after the breakage at the breathing levels for a child (300mm above the floor) and an adult (1500mm).

The study concluded that:

  • “The averaged one hour concentrations were not likely to be a health risk - even if the broken bulb was not cleaned up immediately”; and
  • “adequate ventilation and clean up results in lower mercury concentrations”.

For both scenarios “human health risk is unlikely”.

The report can be downloaded from the Ministry of Health website.

Who did this study?

The study was performed by US-based Toxicology Excellence for Risk Assessment (TERA), under contract to the Institute of Environmental Science and Research Limited (ESR) and the New Zealand Ministry of Health.

TERA’s business is to “protect public health by developing and communicating risk assessment values, improving risk methods through research, and educating the public on risk assessment issues.”

… “this assessment was conducted by an independent, non-profit organisation, using state-of-the-science chemical risk assessment methods to protect public health”.

TERA used data from several different laboratory experiments where CFLs were broken in a controlled environment and the mercury-vapour concentrations measured over time.

Our advice

  • Consumer endorses CFLs as a way of reducing household energy bills and the CO₂ emissions from electricity generation.
  • Be careful when handling CFLs – try not to break them. Don't use excessive force and try to hold the CFL bulb by the base and not the tubes when fitting it.
  • Don't use them in places where they are likely to get broken.
  • If a breakage occurs, children and pregnant women should stay away from the room. Ventilate the room and use the recommended clean-up procedures.

CFL clean-up

To clean up safely after a CFL is broken, follow these steps.

  • Mercury vaporises readily at room temperature, so ventilate the room (by opening all the windows) for 15 minutes before you start the clean-up. Turn off all heating/air conditioning systems, heat pumps and dehumidifiers.
  • Don’t use a vacuum or a broom - this could vaporise the mercury and spread it through the room (as well as contaminating the vacuum cleaner or broom).
  • Put on a pair of rubber of latex gloves before cleaning up. This will help protect you against any cuts from the broken bulb.
  • Sweep up the big pieces of broken glass with a piece of stiff paper or cardboard. Then wrap these pieces in newspaper and place in a plastic bag. Use the sticky side of duct or some other wide tape to clean up the smaller pieces. Wrap these in newspaper too and place in the bag.
  • Wipe down the area with a damp paper towel. Place the used paper towels (and your gloves) in the plastic bag.
  • Store the sealed bag outside until the next rubbish collection.

Savings calculator

Find out how much you could save by switching to energy-saving bulbs.


  • Figures for savings are indicative only. Assumptions below.
  • The most savings can be made by switching to energy saving bulbs in areas where the lights are on for the longest, such as living rooms, hallways and stairs.


  • We assume you replace 100 Watt ordinary bulbs with 20 Watt energy efficient bulbs.
  • We haven't factored in the costs of the bulbs because although energy saver bulbs are more expensive than ordinary bulbs they last much longer, so overall bulb cost is approximately the same.
  • We assume electricity costs 25 cents per kWh.