Energy plays a major role in Australian households, which use a variety of energy sources for heating, cooling, cooking, entertainment and transport. In 2022–23, households consumed 10.5% of Australia’s total energy.
The good news is that Australia’s energy productivity is improving – that means we are doing more with the same or less energy. Average energy use per household has been falling over the past 2 decades, mostly because of more energy-efficient lighting, heating and cooling, water heating and appliances.
Households can significantly reduce their energy consumption by using passive design principles in new homes and renovations, changing behaviour to reduce energy consumption, and buying energy-efficient appliances and technologies. Switching to renewable energy sources such as rooftop solar, further reduces greenhouse gas emissions. New products are bringing improved energy efficiency within easier reach, and upfront investment in your home can provide long-term savings.
In this post we’re looking at some of the popular passive and energy saving lighting options available
Lighting in homes consumes around 10% of the average household electricity budget (or about 7% of its energy use).
While individual light bulbs do not consume large amounts of electricity, the average Australian home contains 37 light bulbs. So choosing efficient and well-designed lighting can still save you energy and money.
Achieving good lighting
Aim to light your home to:
- provide a safe, comfortable, visually appealing and desirable environment
- be as energy-efficient as possible.
Design for light
Thoughtful lighting design combines strategies for daylighting – allowing natural light in through windows, skylights, etc. – and electric lighting to optimise the distribution of light inside the building. It considers:
- the best window sizes, glazing, and shading design for each orientation and room to reflect the expected solar angles, heat gain and glare
- what type of lighting (general lighting, background lighting, task lighting) would suit each room and activity
- the best position for lights to ensure good light distribution in a room.
Daylighting design aspects
The science of ‘daylighting’ aims to use daylight to reduce or eliminate the need for electric light inside a home. Sources of daylight include sunlight, which is an intensely bright, directional beam, and skylight, a diffuse light of about one-tenth the illumination of sunlight.
A goal of all new homes should be to maximise natural daylighting much as possible. Good daylighting design can reduce the amount of energy consumed by the building.
However, done incorrectly, daylighting can affect the building’s thermal performance. For example, direct sun through large windows, particularly in summer, can increase the heat or glare in a room. Occupants are likely to close the curtains or turn on the air-conditioner to reduce these effects which negates any energy-saving benefit that daylighting might have offered.
Careful passive design can deliver both daylighting and good thermal performance.
Lights that can be dimmed, change colour, are automated, or controlled remotely over a network by a device such as a tablet or smart phone can be referred to as ‘smart lighting’. As with other smart home devices, smart lighting requires a reliable wi-fi network and a control device to operate them.
Smart lighting comes in a wide variety of forms and fittings, with many different types of product available. Multiple lights can be connected and controlled (usually via an app but sensors are also available). Smart lighting can be integrated with other smart home devices.
Most smart lighting light bulbs need to be left in standby mode to remain controllable, so they will consume electricity even when they appear switched off when using an app or remote. This can reduce your energy savings. Depending on the amount of standby electricity used (which can vary by product); in worst cases, in terms of total energy use, the smart LED light bulb may be little more efficient than an incandescent light bulb. Checking the smart LED’s standby electricity usage before buying can help reduce this cost – look for 0.5W or less. In order to save the most energy, it is best to turn lighting off at the wall switch. However, this may limit some of the features of having a smart light by requiring manual switching on and off.
- Good lighting design combines opportunities for using natural light (daylighting) with well-designed electric lighting, to provide energy-efficient lighting for rooms and tasks.
- Light bulb technology is improving all the time. Australia has phased out many incandescent bulbs and is phasing out mains voltage halogen bulbs, to be replaced with more efficient products such as light-emitting diode (LED) bulbs and compact fluorescent (CFL) bulbs.
- While CFL bulbs are more energy-efficient and last longer than older technologies, LED bulbs are the most energy-efficient option by far and can last more than twice as long as CFLs.
- Allowing natural light to enter through windows, skylights, etc. can also reduce energy use, however good daylighting needs to be balanced with good thermal design to ensure that sunlight does not increase the need for cooling inside the home.
- Electric lighting design needs to consider lighting for tasks, as well as lighting for rooms. Directed lighting for tasks or features (using lamps or downlights) is more efficient than trying to make the entire room brightly lit.
- The ‘white light’ emitted by light bulbs can achieve different effects, depending on the colour temperature of the light. For example, ‘warm’ light that uses more of the red spectrum can be good for living rooms; ‘cool’ light that uses more of the blue spectrum can be good for garages or bathrooms.
- The colour of light is measured in 2 ways: correlated colour temperature is a measure of the shade of white light; while the colour-rendering index tells you how accurately colours appear under the light.
- Lighting must be installed according to the National Construction Code and relevant Australian Standards. Careful design of switches and controls can help you to avoid using lights unnecessarily.