Heating & energy

Energy efficient lighting

Updated: 08 Jun 2009

Introduction

We find the energy-saver light bulbs that shine brightest and last longest.

Energy-saver light bulbs save you money and also help conserve the country’s energy resources. But which ones give the best light output and keep on switching on? We tested 19 different models – and found a wide variation in performance.

We also look at the options for using energy-efficient lighting to create various moods around your home, and our light bulb calculator will show you how much money you could save by changing to energy efficient light bulbs.

Consumer NZ received funding from the Electricity Commission to test the bulbs and develop the information in this report.

Energy-saver light bulbs

Old-style incandescent light bulbs turn 95 percent of the electricity they consume into heat. Only 5 percent is turned into light. With compact fluorescents (CFLs) the figures are about 80 percent heat and 20 percent light. That’s a big difference. So replacing old-style bulbs with CFLs is worthwhile – especially for lights that burn for a long time.

For our test, we wanted to see how the energy-saver bulbs compared with standard bulbs for light output, and how long they lasted after being switched on and off continually. Most of the bulbs we tested were CFLs – the best of them had a much higher light output (were much brighter) than the equivalent standard bulb and had a long life as well.

About our test

Our lighting test in action

We wanted to see if the CFLs and the halogens were as “bright” as the bulbs they replaced. So we put two samples of 17 CFLs into a special test rig and compared the total light output of each model with the average of the light outputs of seven different 100W incandescent bulbs. We then used a similar process for two energy-saver halogens (the difference being that their light output was compared with the average of two different 60W incandescents).

We also put three samples of all 19 bulbs (CFLs and halogens) into a special rig which switched the bulbs on for five minutes and off for five minutes 10,000 times. The bulbs were continuously monitored so we could tell if and when they failed.

For details of how all the bulbs performed, see the Test results.

Models we tested

This report contains test results and recommendations for the following energy-saver light bulbs:

CFL 100W equivalent

Crompton Light Star
Eclipse 3842140
EcoBulb Warm White
Edapt Mini Spiral B22 TWES20W
E-lite Energy Saving Lamp ES20WB
Envirolux Create Light
GE Entice Warm White
Megaman GSU423
Osram Minitwist Daylight
Osram Minitwist Lumulux Warm White
Philips Ambiance Warm White
Philips Tornado Warm White
Signature Range Warm White PELES20WB
Switch Daylight SWD-SP20B
Woolworths Essentials

CFL 100W equivalent - dimmable

GE Dimmable Warm White
Philips Tornado Dimmable

Halogen energy-saver 60W equivalent

Allume Energy Reduction
Osram Halogen

What we found

Light output

What we did

We tested 19 energy-saver bulbs:17 CFLs and two halogens.

Most of the CFLs were 20W bulbs, equivalent to a 100W standard bulb. Three were 18W. There was one 23W and one 22W bulb.

The CFLs were mainly spiral-tubes, along with one U-tube and two enclosed globes. The spiral shape has virtually taken over the general-purpose CFL market. It gives a more even distribution of light than the earlier U-tube style, which tends to spray most of the light sideways. The spiral shapes were the best performers in our test.

The two halogen bulbs were 42W bulbs, designed to replace 60W incandescent bulbs. Energy-saver halogens are nowhere near as efficient as a CFL. But they’re 30 percent better than a standard incandescent – and they can be used with a dimmer.

CFL performance

We compared two samples of each of the 17 CFLs against the averaged light output of seven 100W incandescents. This averaged “incandescent” figure formed our baseline; and the light output of the energy-saver bulbs is their relative performance against this baseline.

The CFL with the highest light output was the Woolworths Essential, which was 47 percent brighter than our baseline. Next-highest light output came from the Philips Tornado Warm White and the Philips Tornado Dimmable.

Eleven bulbs were brighter than the baseline and eight weren’t.

The worst performers were only 80 and 81 percent of the baseline: these were the Envirolux Create Light and the Edapt Mini Spiral B22 TWES20W.

CFLs that look like a traditional bulb are useful if the bulb is visible and you don’t like the look of the spirals. But both of the globe shapes in our test produced light below the baseline – so use them only for places where you want the look of a traditional bulb.

Two of the CFLs we tested can be used with dimmers: the Phillips Tornado Dimmable and the GE Dimmable Warm White. Both performed well and are recommended, but they aren’t cheap. The Philips cost $19.99 and the GE $25.92.

Halogen performance

We tested the two energy-saver halogens separately.

Because these halogens are meant to be equivalent to 60W incandescent bulbs, we compared them (using two samples of each model) against the averaged light output of two different 60W incandescents. Both halogens produced only about 75 percent of the light output of a standard 60W bulb.

Long life

What we did

We put three samples of all the models through a test that switched them on for five minutes and off for five minutes continually. The bulbs were monitored so we could tell if and when they failed. Initially we reported on progress after 6454 cycles, but we didn't stop there. We finally switched off the rig after a full 10,000 cycles.

Performance

Ten models had no failures during the 6454 on-off cycles (and six of these get our recommendation). The extra 3546 cycles extracted their toll, with a further 9 bulbs failing. But the overall results were still impressive. After the full 10,000 cycles there were 33 bulbs from the initial 57 still going.

Of our four recommended non-dimmable models, one Ecobulb failed at 9445 cycles and one Osram Minitwist Daylight at 9432 cycles. Of our two recommended dimmable models, two GE dimmable bulbs failed at 7457 and 9013 cycles.

We think failure at these sorts of figures is quite reasonable. If you turned a light on and off twice a day for 6 years, it would only come to 4380 switching cycles. These results don’t change our recommendations from the initial test.

Not so good
During the initial 6454 cycles, the Edapt, E-lite and Signature Range had all their samples fail.

There was some pattern to the failures. Generally, the more expensive big-name brands lasted longer than the lesser-known or home brands. But some big brands had their failures too – most notably one of the Philips and an Osram (see our test results). The lamps that failed just stopped working - there were no fires, explosions or other undesirable events.

On the whole, you can be confident that for the extra cost a good-quality CFL will repay you with a long life. Both the halogen energy-saver models lasted the full test distance.

Keeping bright

The light output from all fluorescent bulbs usually reduces over their lifetime.

To check this, we put the top three bulbs – the Philips Tornado, Ecobulb, and GE Entice – back into our light-output test rig at the end of the initial “long life” part of our test. We then compared their light output with the figures we’d obtained when they were new.

In all three cases the light output was within 10 percent of the original values. Not bad after 6454 switching cycles.

Test results

Guide to the table

Our test was funded by the Electricity Commission and carried out in an independent laboratory in New Zealand.

Price is based on a price survey in April 2009. Prices are per bulb.
Light output (60% of overall score) is based on Relative light output (see below).
Switching life (40% of overall score) is calculated on the number of on/off cycles the bulb could withstand, up to a maximum of 10,000.
Relative light output shows the total light output of the bulb compared with the average output of seven 100W incandescent bulbs of different makes.
Watts as claimed by the manufacturer.
Colour temperature is the “warmness” of the bulb’s light – from 2700K (which gives a soft yellowish light suitable for living/relaxing areas) up to 6400K (which gives a harsher “bluer” light suitable for work areas).

We recommend

The recommended bulbs

These bulbs were 19 to 41 percent brighter than a standard 100W incandescent bulb. None failed during the 6454 switching cycles in our "long life" test.

Philips Tornado Warm WhitePrice: $7.48

Ecobulb Warm White Price: $5.95

GE Entice Price: $4.96

Osram Minitwist Daylight Price: $6.56

Philips Tornado Dimmable Price: $19.99

GE Dimmable Warm White Price: $25.92

Lighting guide

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.

Bathroom

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.

Lounge

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.

Kitchen

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.

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.

Outdoors

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.

The rightlight.govt.nz website shows you more about the available options for the various rooms in your home. Consumer NZ worked with the Electricity Commission to develop the information you need to make informed choices about the best energy efficient lighting for your home, available on the rightlight website.

Broken CFL clean-up

CFL clean-up kit

To clean up safely after a CFL is broken, follow these steps from the Right-Light website:

1. 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.
2. 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).
3. Put on a pair of rubber of latex gloves before cleaning up. This will help protect you against any cuts from the broken bulb.
4. 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.
5. Wipe down the area with a damp paper towel. Place the used paper towels (and your gloves) in the plastic bag.
6. Store the sealed bag outside until the next rubbish collection.

For more information see our CFLs and mercury report.

Our advice

Most CFLs produce at least as much light as the old-style incandescent bulbs they replace. Good CFLs produce substantially more.
You can be confident that a good-quality CFL will last well in applications where the lamp is frequently switched on and off.
In most cases, major-brand CFLs last longer than cheaper brands.

Tips for maximum life

We’ve had some comments from subscribers saying they’ve had CFLs fail before they should. Here are a couple of things to avoid:

Most bulbs are marked “Not for use with dimmers”. Never use this type of CFL with a dimmer - even if the dimmer is left turned up to full all the time, it will kill the CFL.
The electronics in the base of a CFL are temperature sensitive. Even though CFLs produce much less heat than an incandescent bulb, putting a CFL into an enclosed fitting is likely to overheat the electronics and shorten the bulb life. CFLs are best suited to fittings that allow some air to circulate around the base of the bulb.

More information

RightLight: www.rightlight.govt.nz