Sustainable Lighting Design
Lighting accounts for around 15% of the energy bill in most homes.
Electricity is typcially provided by fossil fuel driven power plants,
which emit significant levels off carbon dioxide, known to be a
leading cause of global climate change.
Building industries in most developed countries are seeking improved
design and building technolgies towards developing eco-friendly
buildings, which are highly self sustainable.
A key element in sustainable design is lighting. Sustainable lighting
options include:
Natural Daylight Design
Use of natural daylight is the most sustainable
lighting design option. Daylight is a free, renewable resource
that also has proven health benefits. The use of natural daylight
must factor in the requirements to control temperature and glare.
This requires strategic placement of windows, skylights, light shafts,
atriums and translucent panels. Daylighting design harmony ensures
that these elements blend with other building components to reflext
light evenly thorughout internal spaces, taking into consideration
the normal daily tasks performed in each space.
Sunlight Transportation Systems
Sunlight transportation systems are a new technology where natural
sunlight is collected on roof panels and transported into a building
using fibre optic cables. These piping systems can be up to 15 meters,
allowing for piping of sunlight to lower floor levels or across
to sides of building removed from a sufficient degree of natural
lighting. These systems can be used in combination with solar panels
to integrate natural and artificial light systems, to provide an
even spread and availability of light in the home.
Energy Efficient Light Bulbs
Most countries are sponsoring the conversion of standard [incandescent]
household light bulbs to more energy efficient bulbs. Incandescent
bulbs are only 10% energy efficient, that is, 90% of the energy
used is wasted as heat during the conversion to light. More efficient
lighting options include:
Halogen bulbs - burn brighter, use less electricity
and last twice as long as a standard bulb, but are still inefficient
compared with other forms of bulbs.
Compact Fluorescent Lights [CFL] - provide the
same amount of light as incandescent bulbs, but utlise a vastly
more efficient technology, making them 4 times more energy efficient
and 80% cooler.
Hence, to replace a 60-watt incandescent bulb, use a 15-watt CFL.
These bulbs last 10 times longer [up to 20,000 hours], and emit
70% less carbon dioxide. Although more expensive to purchase, their
long life and energy efficiency provides a fast payback and long
term energy savings.
CFL's are available in many different configurations and wattages,
suitable for all lighting purposes.
NOTE: these bulbs contain trace amounts of mercury, which
is hazardous to health and the environment. Care should be taken
in handling broken bulbs and that they are disposed of safely.
Light Emitting Diodes [LED] - small, solid light
bulbs producing light from the movement of electrons when electricity
is passed through the solid semi-conductor material. This is also
called 'solid state lighting', because it uses a solid material,
as opposed to gas (CFL) or filament (incandescent). LEDs are the
most energy efficient; lasting over 100 times longer than incandescent
bulbs, and up to 10 times longer than CFLs. They are also more durable.
LED's are most suited to track and recessed lighting, providing
a pointed, rather than radiated light. LED's are more expensive
than CFLs, but is returned quickly in energy savings. They readily
combine with solar panels to provide reliable, energy efficient
lighting.
Energy Saving Lighting Practices
Use of low energy lighting systems is only one part of the savings
combination. The other factor is in the use of lights. Energy savings
can be made by:
- Turning lights off when not required
- Using dimmers and timing switches
Unfortunately these practices have yet to be incorporated with
all energy efficient bulbs.
Environmental Impact
The presence of mercury in CFL bulbs raises concern for disposal.
albeit the amount used in each bulb is tiny. Regardless, lighting
manufacturers are seeking new technologies that consider the complete
lifecycle of the bulb - manufacture, storage and handling, use and
destruction and disposal.
Whilst initial advancements are encouraging, sustainable lighting
design is still in its infancy.
Next: Sustainable
Water Management Systems
Back to Top
Sustainable Homes Index | Defining
Sustainability | Energy Efficient Homes
| Zero
Energy Buildings | Sustainable Home
Design | Energy Efficient Appliances
| Heating | Active
Solar | Passive Solar | Solar
Water Heating | Geothermal
| Lighting | Water
Management | Updates
|
