Smart lighting

Smart Lighting Technology

Since the first caveman learned to control fire, humans have shaped and used light in a constantly expanding array of technologies. Yet lighting – “smart lighting” – could do much more, according to E. Fred Schubert, Wellfleet Senior Distinguished Professor of the Future Chips Constellation at Rensselaer.

What is Smart-Lighting? Smart Lighting is a lighting technology designed for energy efficiency. May include high efficiency fixtures, day lighting and automatic controls that make adjustments based on conditions such as occupancy.

Current statistics reveal that 65 percent of energy consumed in the US is by the commercial and industrial markets and 22% of this energy is being utilized for lighting alone. We can see that lighting energy takes up a lot of energy and even 1 percent of saving on that part will matter a lot in energy efficiency.

History

Lighting is the deliberate application of light to achieve some aesthetic or practical effect. It includes task lighting, accent lighting and general lighting.

For a long time, people only focus on how to make the lighting source be brighter. When time goes on, the energy consumed by lighting is growing to be bigger and bigger. As a result, to make the use of lighting more efficient is the main topic. People are trying to use the smart control and more energy-efficient lighting source to achieve their goal. This is the origin of Smart Lighting Technology.

Energy Consumption

Usually lighting consumes a lot of electrical energy every day all around the world. According to the statistics, 20 to 50 percent of total energy consumed in homes and offices are used for lighting. What is surprising to us is that over 90 percent of the lighting energy expense used for some of the buildings is unnecessary due to the over-illumination.The cost of lighting can be very realistic. For a single 100 W light bulb, it will cost over $50 if it is used for 12 hours per day (0.12/kWh). As a result, lighting can take a large part of the energy consumption, especially for large buildings.

Minimizing Energy Usage

There are several approaches we can use to minimize energy usage, at least for lighting:

1. Specification of illumination requirements for each given use area.
2. Analysis of lighting quality to ensure that adverse components of lighting (for example, glare or incorrect color spectrum) are not biasing the design.
3. Integration of space planning and interior architecture (including choice of interior surfaces and room geometries) to lighting design.
4. Design of time of day use that does not expend unnecessary energy.
5. Selection of fixture and lamp types that reflect best available technology for energy conservation.
6. Training of building occupants to use lighting equipment in most efficient manner.
7. Maintenance of lighting systems to minimize energy wastage.
8. Use of natural light - some big box stores are being built (ca 2006 on) with numerous plastic bubble skylights, in many cases completely obviating the need for interior artificial lighting for many hours of the day.
9. Load shedding can help reduce the power requested by individuals to the main power supply. Load shedding can be done on an individual level, at a building level, or even at a regional level.

Potential Improvement for Lighting

New photonic crystal light emitters will be 10 to 30 times more efficient than light bulbs, says Shawn-Yu Lin, Future Chips Constellation Professor and professor of physics. They will have a huge impact on worldwide energy consumption and the environment. It will be possible to change their color and their intensity independently, so that a homeowner can easily adjust both to match the time of day, the current use of the area, or the mood of the occupants.

Major Technique for Smart Lighting

Smart Lighting Control

General Idea

Smart Control Technology (Building automation and lighting control solutions) are now available to help reduce energy usage and cost by eliminating over-illumination and unnecessary waste. These solutions provide centralized control of all lighting within a home or commercial building, allowing easy implementation of scheduling, occupancy control, daylight harvesting and more. Many systems also support Demand response and will automatically dim or turn off lights to take advantage of DR incentives and cost savings.

Daylight Sensing

In response to daylighting technology, daylight-linked automated response systems have been developed to further reduce energy consumption. These technologies are helpful, but they do have their downfalls. Many times, rapid and frequent switching of the lights on and off can occur, particularly during unstable weather conditions or when daylight levels are changing around the switching illuminance. Not only does this disturb occupants, it can also reduce lamp life. A variation of this technology is the 'differential switching or dead-band' photoelectric control which has multiple illuminances it switches from so as not to disturb occupants as much.

Occupancy Sensing

Occupancy sensors to allow operation for whenever someone is within the area being scanned can control lighting. When motion can no longer be detected, the lights shut off. Passive infrared sensors react to changes in heat, such as the pattern created by a moving person. The control must have an unobstructed view of the building area being scanned. Doors, partitions, stairways, etc. will block motion detection and reduce its effectiveness. The best applications for passive infrared occupancy sensors are open spaces with a clear view of the area being scanned. Ultrasonic sensors transmit sound above the range of human hearing and monitor the time it takes for the sound waves to return. A break in the pattern caused by any motion in the area triggers the control. Ultrasonic sensors can see around obstructions and are best for areas with cabinets and shelving, restrooms, and open areas requiring 360-degree coverage. Some occupancy sensors utilize both passive infrared and ultrasonic technology, but are usually more expensive. They can be used to control one lamp, one fixture or many fixtures.

Definition

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Fig. 1 Electricity Consumption for Lighting

Smart Lighting Control refers to a system that controls the on/off condition of lighting in a building. Usually it detects the human occupancy and makes judgments based on that. A large amount of energy will be saved with this technology.

The devices with Smart Lighting Control will automatically turn off lighting and other equipment based on their detection of motion in a specific area. Originally developed for security systems, occupancy sensors have since been engineered to control not only lighting but also HVAC systems for commercial spaces. These devices have grown more common recently as energy management has become a priority. For example, the typical office uses 29% of its electricity for lighting. Occupancy sensors can reduce this use by half. The table below shows potential electricity savings from using occupancy sensors to control lighting in various types of spaces.

Components

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Fig. 2 Smart Lighting Control System

A complete sensor consists of a motion sensor, an electronic control unit, and a controllable switch/relay. The detector senses motion and determines whether there are occupants in the space. It also has a timer that signals the electronic control unit after a set period of inactivity. The control unit uses this signal to activate the switch/relay to turn equipment on or off.

For lighting applications, there are three main sensor types: passive infrared, ultrasonic, and hybrid.

Passive Infrared (PIR)

PIR is an electronic sensor that measures the infrared radiation being emitted from an object in its view. Motion is detected when an infrared source, such as a human, passes in front of another infrared source with a different temperature such as a wall. PIR sensors react to the changes in heat patterns created by the moving person and turn lights on accordingly.

The advantages of passive infrared are that they are highly resistant to false triggering, relatively inexpensive, and do not radiate any energy (hence the name “passive”). The disadvantages are that they are strictly for line of sight use, and cannot see around objects. Doors, stairways and partitions have a tendency to block motion detection and reduce effectiveness. Also, the farther away the object to be detected is, the larger the motion needs to be to trigger the device.

Ultrasonic Sensors

Ultrasonic sensors emit an inaudible sound pattern and then “read” the reflection. This sound is above the range of human hearing. A break in the pattern caused by any motion in the area triggers the control. Ultrasonic sensors can “see” around obstructions and are best for areas with cabinets and shelving, restrooms and open areas requiring 360-degree coverage.

Hybrid

Some occupancy sensors use both passive infrared and ultrasonic technology. They can be used to control one lamp, one fixture or many fixtures. They are usually foolproof, allowing for wide coverage and range of applications.

The disadvantages are that they are more expensive, and may require more adjustments. Because they use both technologies, hybrid sensors can be used to control lighting in almost any space, however large open areas and areas with irregular occupancy patterns are generally the most cost effective.

The advantages of ultrasonic devices are that they are sensitive to all types of motion and generally there are zero coverage gaps, since they can detect movements not within the line of sight.

Others

Motion-detecting (microwave), heating-sensing (infrared), and sound-sensing; Optical cameras, IR motion, Optical trip wires, Door contact sensors, Thermal cameras, Micro radars;

Sensor Setting and Placement

Proper placement and orientation of occupancy sensors is crucial. They must be able to sense all occupants to avoid inadvertently turning off lights while the space is occupied. In addition, the sensor must not be too sensitive as to cause “false positive” triggering such as the detection of pass-by in adjoining hallways. Occupancy sensors with the sensitivity set too high may not save a satisfactory amount of energy, but too low a sensitivity may cause lighting to shut off inadvertently when the occupants are not making large enough movements, such as during a presentation or in a classroom during a test. This can prove to be very annoying to occupants.

Sensor Belief Networks

Goals

Use cheap sensors in a distributed network (PIR, telephone off hook)

Develop new, more sophisticated control algorithms;

Combine sensor inputs through probabilistic inference to created more accurate occupancy data;

Approach: Belief Network

A collection of conditional probability distributions associated with a directed graph

Occupancy Sensors for Lighting Control.

Sensor Cost

Occupancy sensors range in cost from around $30 to $130, depending on the type and manufacturer. The simple payback period from their installation ranges from 0.5 to 5 years, depending on the level of occupancy and the potential for energy savings in the building or area.

Energy Saving

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Energy Saving for A Typical Day Source: Lutron Electronics Co.

NCSU Facilities Staff is testing the use of occupancy sensors as a retrofit application in various classrooms in Dabney and Broughton Hall on the North Carolina State University campus. The sensors were installed by NCSU Facility Management staff and classroom energy consumption and occupancy has been monitored by the NCSU Industrial Assessment Center (IAC). Initial adjustments were made to sensor’s sensitivity to reduce ‘false triggers’ by passersby outside of the classrooms. IAC staff also recommend the use of dual sensing technologies for optimum performance. Sensors were installed in a drop acoustical tile ceiling.

IAC staff have measured an approximate reduction of 30% in lighting electrical load since the installation of the sensors. After the optimization of the sensors, students and instructors have been pleased with lighting control functions.

In the paper "Energy savings due to occupancy sensors and personal controls: a pilot field study", Galasiu, A.D. and Newsham, G.R have confirmed that automatic lighting systems including occupancy sensors and individual (personal) controls are suitable for open-plan office environments and can save a significant amount of energy (over 30%) when compared to a conventional lighting system, even when the installed lighting power density of the automatic lighting system is ~50% higher than that of the conventional system.

Semantic Interoperability Architecture for Power Management Smart Lighting

In this approach, the rooms of building are divided into two categories: (1) high priority rooms that are allowed to use power according to whatever demand there is at that time (2) low priority rooms that are obliged to use the power that is left over from the quota after the consumption of high priority rooms.

In this scenario, high priority rooms (R_high) are deployed with power measuring lamps, light sensors and motion sensors. The light outputs of power measuring lamps are automatically adjusted as the user activity changes, consuming a certain amount of power for each activity.

Smart lighting systems in the low priority rooms (R_low) are implemented using the OSAS (Open Service Architecture for Sensors) – an architecture for programming a network for sensors and actuators.

Semantic interoperability between these two different architectures is realized by using the Smart-M3 platform. Smart-M3 (multi-vendor, multi-device, multi-domain) is a solution for information interoperability, provided by the SOFIA1 project. Elements called Knowledge Processors (KP) and Semantic Information Brokers (SIB) form a Smart-M3 network.

Principle

When the power quota is large enough to support all activities in R_high and R_low, the sensor readings in these rooms are used to set and maintain the illumination based on the user preferences and the activity performed in the room, e.g. reading, sleeping, watching TV. If the illumination measured differs from the desired illumination, the light outputs of the lamps are automatically adjusted by the KPs in each room till the desired illumination is achieved.

Basic Idea

A KP is an entity that produces or consumes information according to the ontology relevant to its defined functionality. A SIB is an entity, in which high level information for a smart space is stored and maintained. This information can be used and updated by a KP.

GWKP: Gateway KP

SIB: Semantic Information Brokers

RDF: Resource Data Format

R_high: All KPs in R_high individually and periodically update their power consumption values at the SIB. As these are high priority rooms, the lamps in R_high can utilize almost the entire power quota when necessary.

R_low: The GWKP translates contextual information between RDF triplet format and OSAS message format that is readable by OSAS sensors and actuators. When the power quota is not sufficient to support R_low and R_high simultaneously, the GWKP dims the illumination in Rlow down to an acceptable level. Depending on the R_high power consumption information, retrieved via a subscription/query to the SIB, the GWKP brings the power consumption in R_low just below the remaining power budget for Rlow.

Achievements

Power consumption management for smart lighting is accomplished without exceeding a given power quota. When the power quota for lighting is sufficient to support all rooms and all activities in a building, the desired illumination levels in both room types are set and maintained automatically based on the user activity. When the power quota is not able to support the low priority rooms, low priority room lamps are dimmed down to utilize the leftover power budget from the high priority rooms.

Smart-Lighting Emergency Ballast for Fluorescent Lamps

The function of a traditional emergency lighting system is the supply of a minimum illuminating level when a line voltage failure appears. Therefore, they have to store energy in a battery module to supply the lamps in that case of failure. In this kind of lighting systems the internal damages for example battery overcharging, damaged lamps and starting circuit failure must be detected and repaired by specialist workers.

For this reason, the smart lighting prototype can check its functional state every fourteen days and dump the result into a LED display. With these features they can test themselves checking their functional state and displaying their internal damages. Also the maintenance cost can be decreased.

Key Idea

The main idea is the substitution of the simple line voltage sensing block that appears in the traditional systems by a more complex one based on a microcontroller. This new circuit will assume the functions of line voltage sensing and inverter activation, by one side, and the supervision of all the system: lamp and battery state, battery charging, external communications, correct operation of the power stage, etc., by the other side.

The system has a great flexibility, for instance, it would be possible the communication of several devices with a master computer, which would know the state of each device all the time.

A new emergency lighting system based on an intelligent module has been developed. The micro-controller as a control and supervision device guarantees increase in the installation security and a maintenance cost saving.

Another important advantage is the cost saving for mass production specially whether a microcontroller with the program in ROM memory is used.

An Internet Address for Every Light Bulb

What if every light bulb had its own unique Internet IP address? You could monitor, manage and control every light bulb from any Internet-enabled device—turning lights on and off individually, dimming or creating scenes from your smartphone, tablet, PC or TV—to save energy as well as electricity costs. Your "smart lighting" network could have dozens or even hundreds of appliances connected through a wireless network designed for maximum energy savings, communicating information about their environment, about power consumption levels, and alerting you to any problems.

GreenChip Smart Lighting Technology

The GreenChip smart lighting solution is available in two versions—GreenChip iCFL for compact fluorescents and GreenChip iSSL for LEDs—and currently includes: (1) The GreenChip iCFL or GreenChip iSSL chipsets, which function as highly efficient, dimmable drivers for smart lamps.

(2) An ultra-low-power standby supply controller with 10 mW no-load capability; standby power is particularly critical in smart lighting applications where lamps are continuously "listening" for the command from the user and/or network.

(3) A 2.4-GHz IEEE 802.15.4 standard-compatible wireless microcontroller with a Tx/Rx current below 17mA.

(4) Low-power, IP-based wireless connectivity enabled by JenNet-IP network layer software.

JenNet-IP Network Drives Home and Industrial Connectivity

GreenChip-enabled light bulbs will be able to operate on the same wireless sensor networks consumers may be using at home for energy metering, smart appliances and security systems. NXP's JenNet-IP network layer software provides the ultra-low-power wireless connectivity in the GreenChip smart lighting solution.

Smart Lighting Ecosystem

GreenWave Reality is introducing a breakthrough intelligent lighting control and management solution based on the GreenChip smart lighting solution. GreenWave Reality's IP-based platform wirelessly connects GreenChip-enabled bulbs, running JenNet-IP software, to provide users with a feature-rich lighting application. The application can be used stand-alone or as part GreenWave Reality's innovative energy management solution. The GreenWave Reality solution benefits both consumers and commercial customers by allowing them to save energy and simplify their lives by adding lighting Smart Controls.

For instance, consumers can dim or turn lights on and off using Home, Away, and Night Smart Controls from any combination of devices such as a PC, smartphone, and even a TV. A Smart Control can adjust indoor lighting according to outdoor lighting conditions. Other Smart Controls can automatically turn lights off when no one is in a room. Similarly, these advancements are extended to commercial and hospitality customers who can reduce ongoing lighting and related maintenance costs with this advanced lighting control system.

Other Smart Lighting Technology besides Energy Efficient Part

Allergy Detection

A person with a serious allergy to shell food or peanuts could carry the device and test food for herself to be sure of its safety. “The computers exist. The limiting factor is the light source, and we’re the ones working on that,” he says. “The computers are already very smart. They are waiting on us to provide the data.”

Information Transmitting with Smart Light

Schubert predicts that revolutionary lighting systems will provide an entirely new means of sensing and broadcasting information. By blinking far too rapidly for any human to notice, the light will pick up data from sensors and carry it from room to room, reporting such information as the location of every person within a high-security building. A major focus of the Future Chips Constellation is smart lighting, a revolutionary new field in photonics based on efficient light sources that are fully tunable in terms of such factors as spectral content, emission pattern, polarization, color temperature, and intensity. Schubert, who leads the group, says smart lighting will not only offer better, more efficient illumination; it will provide “totally new functionalities.”

Smart Lighting for Daily Life

Studies have shown that spectral (color) variations in light have profound effects on the human circadian and visual systems (See related article from Rensselaer’s Lighting Research Center). Controlling the amount of red, yellow, and blue in white light has implications for sleep in Alzheimer’s patients, growth of premature infants, seasonal depression, jet lag, and the well being of nightshift workers.

Medical Purposes

Some researchers have suggested that inappropriate lighting can upset the body chemistry and even lead to certain types of cancer. In live-cell biological imaging, smart lighting could make it possible to coordinate intensity, wavelength, and polarization with image scanning to reveal a new wealth of features. Using this revolutionary cellular microscopy technique, for example, researchers could observe and analyze multiple single cells in real time as they react to a drug or infectious agent.

Potential in the “Century of the Photon”

Someone says that the new century is the Century of the Photon. The advances achieved in photonics are already transforming society just as electronics revolutionized the world in recent decades and it will continue to contribute more in the future. From the statistics, North America’s optoelectronics market grew to more than $20 billion in 2003. The LED (light-emitting diode) market is expected to reach $5 billion in 2007, and the solid-state lighting market is predicted to be $50 billion in 15–20 years, as was said by E. Fred Schubert, Wellfleet Senior Distinguished Professor of the Future Chips Constellation at Rensselaer. It is obvious that Smart Lighting Technology will bring us to a more comfortable life in the future, not far away.

See also

• Anglepoise lamp, successful and innovative desk lamp design
• Automotive lighting
• Banning of incandescent light bulbs
• Candlepower
• Domotics, computer controlled home lighting
• Fishing light attractor, underwater lights to attract fish
• Light fixture
• Light in school buildings
• Light pollution
• Lighting control systems, for a buildings or residences
• Lighting for the elderly
• List of Lighting Design Software
• Luminous efficacy
• Over-illumination
• Seasonal affective disorder
• Stage lighting
• Sustainable lighting
• Three-point lighting, technique used in both still photography and in film
• Street lighting
• Ultrasonic Sensors
• Passive Infrared Sensor

Inventors

• Joseph Swan, carbonized-thread filament incandescent lamp
• Alexander Nikolayevich Lodygin, carbon-rod filament incandescent lamp
• Thomas Edison, long-lasting incandescent lamp with high-resistance filament
• John Richardson Wigham, lighthouse engineer

Lists

• List of light sources
• Timeline of lighting technology

External links

• UK Smart Lighting Specialists official Web site
• Illuminating Engineering Society of North America official Web site
• ENLIGHTER.ORG online Lighting Design magazine
• IESNA Advanced Lighting Guidelines
• Lighting Research Center @ Rensselaer Polytechnic Institute
• Shedding Light on Home Lighting Use by Lyle Tribwell (Home Energy magazine online
• EE209AS, Green Computing and Communication Systems
• Smart Lighting Engineering Research Center
• Lighting Control
• Smart Lighting Group, UC Berkeley