Lighting
Cutting your power use is as easy as changing a light bulb.
Lighting accounts for up to 15% of household energy use.
By changing to energy efficient lightbulbs in most rooms, and making better use of the sun, you can cut your lighting costs. This saves electricity, which means lower bills and reduced greenhouse gas emissions (as there is less need for electricity to be made by burning fossil fuels).
Energy-saving tips
Use the sun!
You can save energy by:
- opening blinds and curtains fully so they don’t block the window
- making rooms lighter by using light-coloured paints
- working near windows instead of in darker corners
- pruning trees and foliage around windows to let in sunlight.
If you're designing a new home or renovation, it's worth thinking about how to make best use of natural light. You can also design your home or renovation to maximize natural light, through good design and placement of windows and skylights. Open plan living, and translucent doors and partitions, can also help to spread light around.
Other energy savers
Here are some ways to use lighting efficiently and reduce your energy bills.
- Use dimmers for incandescent bulbs to reduce the energy used. This also makes them last longer.
- Use low-wattage lights shining directly onto work areas and lower-level background lighting, rather than lighting a whole room to the light level you need for work.
- Likewise, don’t use spotlights if you need to light the whole room.
- Turn off the lights when you leave the room!
Timers or movement sensors can switch lights off if you forget, but note that they use standby energy even if the lights are off. It is cheaper to use manual switches.
Lighting options
Standard incandescent light bulbs
Incandescent or tungsten bulbs have been around for well over 100 years. They are cheap to produce and dispose of, but they are very inefficient, turning only about 5% of the energy they use into light. The remaining 95% is turned into heat. They also have a short lifespan, typically 1000 hours.
Fluorescent lights
Fluorescent lights are the most energy-efficient form of lighting for households. They are a little more expensive to buy than standard incandescent light bulbs but are much cheaper to run and last longer.
They're available as fluorescent tubes or as compact fluorescent lights (CFLs) which can fit in a normal light socket.
CFLs can give as much light as incandescent bulbs yet use only about 20% of the electricity. They last up to 10,000 hours. This is about 10 times longer than the life of a standard bulb. The savings can amount to over $100 over the life of the light.
Compact fluorescent lights:
- generally don’t work with dimmers
- need a short time to reach maximum light output - up to about a minute
- are available in colours similar to incandescent light bulbs.
CFLs are good for places where you want general background lighting and where the lights are on for a long time, such as the living room and kitchen. They're also good for security lighting, but may be less useful for directional lighting or for places where you may only want light for a short time such as the toilet or laundry.
Though most CFLs have a longer, thinner shape than standard incandescent light bulbs, some sold in New Zealand have the same shape as the standard bulbs.
Fluorescent tubes and compact fluorescent lamps contain mercury and cadmium. They should be disposed of as hazardous waste. Contact your local council or landfill about your disposal options. Auckland company Medichem recycles fluorescent lights - it may have a depot or be able to collect CFLs and fluorescent tubes in your area (see www.medichem.co.nz for further information).
The Ministry for the Environment website has a factsheet about safe use and disposal of fluorescent lamps.
Halogen lamps
Halogen lamps are a modified form of incandescent lamp. They are more expensive to buy but last about twice as long. They can be either 240V bulbs or low-voltage bulbs. Neither is as energy efficient as a compact fluorescent light.
All halogen lamps require special light fittings. Halogens lamps are often recessed and this may require holes in ceiling insulation through which heat can escape.
They're often used for spotlighting paintings or for task lighting directly over a cooking area or desk. They are not good for background lighting.
If you use halogens:
- fit lower wattage and more efficient bulbs - an efficient 35W lamp can produce as much light as a standard 50W lamp
- don’t touch the lamp with your hands - its life will be reduced.
Mains-voltage halogen 'torchiere' lamps can get very hot and have started fires.
LEDs (light emitting diodes)
LEDs come in various colours and are used extensively in traffic lights, head torches and car tail lights. Light from a LED is directional, making them ideal for use in applications such as torches and downlights.
Recent developments have made LEDs suitable to use for general lighting in buildings where they can replace halogen, incandescent and fluorescent lamps. They are expensive to install or retro-fit, but LED technology is contantly improving.
LEDs are also very energy efficient and give off hardly any heat, although they should be connected to a heat sink for durability and efficiency. They can last for an incredible 30,000 hours, but fade with time so are likely to emit only half the amount of light once they have been on for that amount of hours. This fading needs to be considered when specifying and intalling LEDs.
LEDs emit no harmful UV or IR rays and have no toxins.
More information
From Smarter Homes
From consumer.org.nz
Note: you may need to be a subscriber to access some of this content.
From other sites
The Energywise website has information about energy efficient lighting. The Energy Efficiency and Conservation Authority’s website has information about labelling and standards for energy efficient lights.
The Waitakere City Council has a factsheet Lighting (PDF, 71KB).
