A 360o Approach & Beyond
LED lighting is the best choice to reduce energy consumption. It uses only 20% energy than an equivalent incandescent lamp. It also liberates much less heat than an incandescent bulb which in turn reduces the heat load on air conditioning...
- Rajesh Chourishi
Light Emitting Diode (LED) is regarded as 4th generation of light sources following incandescent lamps as first generation, fluorescent lamps as second and High Intensity Discharge (HID) lamps as third.
High efficiency, long life, compactness, light weight, mercury free, very weak Infrared (IR) and Ultraviolet (UV) emission etc. are their merits.
Presently LEDs are used in sign and display devices, spot lighting, base lighting, security lighting etc. Their applications are growing tremendously.
LEDs are solid-state devices that convert electric energy directly into single coloured light. In it, most of the energy is delivered in the visible spectrum. LEDs don't waste energy in the form of heat. Therefore, it is called 'Cold' light generation technology.
LED smart control system has two concepts, first is through the sensor which changes the Lumen of LED and let the light accommodate people; second, light as the transmission medium, human as the acceptor. The control system is not only to change the luminosity but also for communication, sensing, computing, Internet and other modern technologies. The effect of light goes beyond illumination.
The efficiency of a light source is determined by luminous flux emitted per unit of power consumed by it.
LED lighting is the best choice to reduce energy consumption. It uses only 20% energy than an equivalent incandescent lamp.
It also liberates much less heat than an incandescent bulb, which in turn reduces the heat load on air conditioning. Also, LEDs last significantly longer than incandescent or fluorescent bulbs thereby reducing maintenance.
Annual operating cost comparison
Annual operating cost comparison of LED, CFL and Incandescent lamps is given in the following table 1.
Table 1: The analytics below shows operating cost of LED is much lower than others...
Transformation of workplace lighting
Transformation of lighting from first generation to latest generation is helping in saving energy as well as improving office environment.
Some guidelines are given herewith for workplace lighting transformation.
Upgrades that pay for themselves
Some organisations provide funds for energy-saving projects and recover it from the savings on electricity bills.
Controls over fingertips
The most efficient light source is one that can be controlled smartly.
The controls have come on a fingertip with the rise of LEDs.
It should be adopted for improvements in user interfaces for an existing building.
Comparison of latest generation lamp with first generation lamp...
The end of louvre
To avoid glare on a computer screen, the latest guidance for the transformation of workplace lighting can be adopted, i.e., put the focus where it is required.
Adapting task lighting
To improve staff productivity and energy saving in their domain, task lighting is getting more popularity. Some countries have a stronger tradition of task lighting.
Well-being and productivity
Health, happiness, and productivity are now big considerations for workplace lighting. This can be achieved by smart control of lighting like an intense blue-rich light in the morning or at times of alarms, softer light during afternoon and evening.
Energy Management System (EMS)
Bigger energy savings can be achieved by spotting patterns and understanding, 'how buildings are used?' This can be identified by an Energy Management System (EMS).
The trend of building lighting control system continues like Manual-Auto-Smart.
Smart control of lighting for building reflects digitisation, intelligent building networks, 'safety and security' technologies, and the impact of light on humans.
The smart control system can be programmed for pre-determined patterns of light, to highlight a special piece of art, to dim or brighten them, and for automated impact on a location with a simple click of a button.
Smart control of office light
In the office, there are several places where lighting can be controlled smartly by the task-oriented lighting controller.
Occupancy and daylight sensors can be programmed for need-based lighting.
Moreover, by use of a dimmer with on/off control light level can be controlled.
A simple Passive Infrared (PIR) sensor will ensure that the lights are only ON when a person is there.
Daylight and occupancy sensors can control the illumination. Only care should be taken for positioning of sensors. It should be positioned properly so the lights switch ON before the person crosses the corridor.
By the windows (Daylight harvesting)
To use sunlight, luminaires can be zoned into groups. Thus, fixtures located near the windows may be dimmed during the day and the people away from windows will get full artificial light.
For meetings, presentations or events, choice of ‘scenes’ is needed to make sure that the illumination suits 'what's going on.'
If people are scrutinising the notes, put light on the table. If they are watching a presentation, dim the lights to focus them on the projection. If they are watching a speaker, dim the lights and highlight the speaker.
Clusters of desks
In the office, the area of work and walk can be differentiated. Zone the lights so these areas can be treated differently.
Position the sensors accordingly to control the illumination level.
The last man out
A ‘last man out’ switch is one way to make sure your lights do not leave ON needlessly when there is nobody.
Energy efficient office lighting scheme
For successful, energy-efficient office lighting scheme, do not get hung up on the watts per square metre figure. That’s the advice of 'Andrew Bissell,' Head of Cundall’s lighting division. Actually, energy efficient office light should be need-based with smart controls.
Latest trends in lighting technology
In lighting technology various developments are going on.
Some of the latest trends in lighting technology are given below.
Built-in light sources
Since LED light sources do not have to be replaced very often, and because no standards have emerged for what they should be like, manufacturers have got used to building them into fittings, rather than designing new luminaires around replaceable ‘lamps.'
New power technologies
In LED lighting, Drivers are often the first component of a lighting system to fail. Therefore, manufacturer developed a lamp with a DC LED chip that needs no driver at all. The latest innovation is power-over-Ethernet that provides electricity through data cables.
Retrofit lamps – on borrowed time
Manufacturers begin to wonder “What happens once the market for these long-lasting lamps is saturated?. World class manufacturers accepted the challenge – and added value to this product like Internet connectivity, colour-changing and so on.
Revolutionary materials-Graphene LED
Researchers at the University of Manchester say graphene’s high conductivity will make LEDs brighter, longer-lasting and more efficient. They hope to have a graphene LED lamp in the market soon.
Advanced efficiency of DC-LED lighting system
In an advance study, innovative DC LED lighting system instead of the conventional AC LED lighting systems is proposed. The benefit of using DC LED lighting system is to overcome the drawback, to convert AC voltage to DC voltage using SMPS for each LED unit, however, using only one SMPS with high efficiency is enough to supply the DC LED lighting system. According to the study, DC LED will save 17.4% of more energy than AC LED lighting system.
LED lighting: challenges
With LEDs comprehensively in the mainstream, the next frontier in lighting is controls. Dimmers and sensors have been around for donkey’s years, but the challenge now is to make them more sophisticated, get them to communicate with other devices.
From T5 to LED
Some areas have been slower to adopt them than others. The efficiency of T5 has been tough to beat in offices, and LEDs have struggled to match the output of floodlights.
Lighting is not just about light anymore. It is about data. Technologies such as Li-Fi that tracks person’s position using LED luminaires and smartphones. It is based on visible light communication. It sends data in light instead of the radio wave. This is done by modulating the light from LEDs in a way that’s invisible to the human eye, but can be picked up by a receiver attached to a computer. The result is a super-fast wireless connection.
Helps to improve business
Poor quality of light makes a shop, café or office look dreadful. But the improved quality of light by LED helps in attracting the customers.
The Internet of things
Currently not only computer, laptop or smartphones are connected to the Internet, but also, your fridge, your coffee cup, your heart monitor and your LED lights are also connected to the Internet. Lighting is an ideal network for 'Internet-of-things' services to be built on – because it is already there in the ceiling of every building, looking down at us, wired up and ready to go. Similarly, every building in the world already has lights all over its ceiling. Only have to add a few sensors or cameras and some kind of data connection to build the perfect network of 'Internet of Things.'
Look, no wires
Everything is going wireless these days, and lighting control is no exception. It is particularly appealing for retrofit projects.
As well as radio-frequency-based systems, there are technologies such as power-line communication, which uses mains power lines to carry data to and from your fittings.
And even for traditional wired control systems, it is going to be more and more common for the user’s control device to be a tablet or phone that’s not wired to anything.
Light quickly recovers a patient from illness. The manufacturers are putting this knowledge into practice and making products that promote health, by adjusting the brightness and colour of the light.
In maternity ward in Hillerod Hospital in Denmark uses a programme of light and sound to help mothers feel more relaxed.
LED helps in reducing carbon footprint
Studies show that 17% carbon footprint is due to lighting alone. The carbon footprint is directly correlated with the amount of electricity consumed. LED lamps and tubes not only consume a fraction of the energy consumed by the incandescent bulbs, they have the double benefit of lasting almost forever and containing no mercury.
By doing nothing except installing LEDs in the home, it is possible to reduce one’s carbon footprint by a whopping six tons per year.
To put it in perspective this saving of six tons is equivalent to reducing gasoline consumption by 700 gallons.
Electrical pollution by LED (Power Quality)
LEDs are versatile and energy efficient. But most of the LED lamps produce a high level of harmonics as compared to the standard set by IEC 61000-3-2. Harmonics adversely affect the power system.
In the three phase power system, triplen harmonic (odd multiple of third like, 3rd, 9th, 15th, 21th…) is the harmonic of primary interest. Since the percentage of higher order harmonics as compared to lower order harmonics remains low, it does not proportionately affect the system.
In case of even harmonics wave shape of negative and positive half cycle (like, 2nd, 4th, 6th…) are identical so they cancel each other. The third harmonic in each of three phase conductors always remains in the same phase. Therefore, when these harmonic currents come together in neutral conductor, they actually add.
Thus, resultant current in neutral becomes more than phase current. As a result, overheating of neutral conductor occurs which deteriorates the insulation. To overcome neutral heating, power system designers have started to recommend four core cables instead of three and half core cables for lighting circuits.
& Energy Services
Aditya Birla Group
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