- Low power consumption (making them ideal for
use in solar-powered applications)
- Long life, which ensures zero maintenance costs:
The life of LEDs is more than 50,000 hours (to 70% lumen
maintenance), as compared to much lower life for conventional light
sources. The LED does not have catastrophic failure, but gradually
degrades to extinction – light output is available even after 20 years
of operation (50% light after 20 years).
- Effective visibility of light output comparable to
different types of conventional lamp luminaires
- High optical conversion efficiency (up to 95%),
as compared to around 50% for CFL-based luminaires
- Light output can be directed in specific directions by
the use of Total Internal Reflection (TIR) lenses; no losses of
reflection/refraction or lamp (source) obstruction in the
luminaire: Such losses occur with conventional lights like
fluorescent, CFL, HPSV, HPMV and metal halide, which emit light in 360,
and thus require a reflecting/refracting luminaire to redirect the light
emitted from the top surface of the lamp. Furthermore, as these light
sources are of a large size and volume, light spillage occurs on to
points where light is not required.
The LED light output is 180 in
nature, and can therefore be directed as desired with Total Internal
Reflection lenses (which enable each LED module to have a different beam
angle). This results in very low luminaire loss and high
efficiency.
- No Light Pollution: Conventional light source
luminaires such as metal halide and HPSMV luminaires are not able to
focus all their light onto the target area, but scatter the output onto
unwanted areas such as windows of nearby buildings (causing disturbance
to occupants at night), and even into the sky. This is known as light
pollution. This unwanted light is not only wasted light, but creates
disturbance and glare to residents, as also to viewers of the night-time
sky.
- NO infra-red or ultra-violet radiation:
Conventional light sources are plagued by infra-red and ultra-violet
radiation, which has detrimental effects.
- Environment-friendly operation (as they contain no
mercury or heavy metals): Mercury (used in fluorescent lamps)
is a haz-ardous substance.
- Loss of a single LED module does not affect the
reliability of the light: In case of conventional single-source
lamp type lights, failure of the light source results in no light.
- Greater Visual Efficiency than HPSV lamps: The
human eye is more sensitive to blue emission in low ambient light
conditions, such as at night time (mesopic region). Given this night
vision property of the eye, even though a high pressure sodium vapour
(HPSV, which consists of predominantly yellow light) has an efficiency
of 100-120 Lm/w, its effective visual utilization is only about 20 Lm/w;
that is, the photopic lux value of the HPSV lamp falls to 1/7th of its
measured value in comparison to a light source having predominantly blue
light output (such as LEDs). As such, a unit lux level of LED light is
visibly equivalent to 7 lux of HPSV at night time (in mesopic light
ambience conditions).
- Better Peripheral vision: The ‘Rods’ in the
human eye, which contribute to peripheral vision, are not activated by
HPSV light. Activities occurring at the periphery of vision may not
register properly (e.g., a motorist may not perceive a pedestrian at the
side of the road), resulting in an accident.
- Better Focus and Perception of Detail: The
pupil of the eye is activated by blue wavelengths, and in its absence
(as in HPSV light) the pupil is wide open. This affects the depth of
focus of the eye, making it difficult to focus on detail.
- Colour Rendering Index (CRI) of HPSV is only 22
(CRI of sunlight at noon is 100). Colours are not seen properly,creating
an unpleasant visual ambience.
- LEDs give more light at lower temperatures:
Conventional discharge lamp operation is dependent on ambient
temperature. At low temperatures, low pressure discharge lamps (like
fluorescent tubes and CFLs) give lower light output. Their striking
voltage also rises, making them difficult to start – which then leads to
rapid failure of the tube.
- Instant switch-on: High pressure discharge
lamps have a delay when first switching on. Moreover, when restarting, a
restarting time is necessary for cooling of gas. LEDs have no such
problem, and light up immediately.
- Vibration resistant: Being solid-state, LED
lamps can withstand shocks and vibration, unlike fragile glass filament
and discharge lamps
- While the
initial capital cost is higher, the total lifetime cost of ownership is
extremely low. The payback period can be as low as 3 to 4 years
(after which the product essentially becomes ‘free’ for the next 10 to
15 years).
- All BINAY
LED Street Lights are covered under a 5-year warranty.
|
|
