electrical 1/4/24 – gtg

TIP! Ensure that your caulking isn’t cracked, worn, separating, or in otherwise poor condition. Periodically check the caulking around your bathtub and sink.


TIP! When did you last look over every door handle in the home you live in? These handles shine a great deal and can make a great impact on the way your house looks. Switch out the door handles in your house and put in some brass handles.

Regardless of your skill or knowledge level, it can be fun and rewarding to engage in home improvement projects. Avoid being tricked by home improvement television shows. Big jobs aren’t the only home improvement jobs. This can even be entertaining, find out how.

TIP! Make sure you get the right measurements for blinds before purchasing or installing them. You can’t buy the right blinds if you don’t know the proper dimensions.

Porches need repainting at times. Use paint that is specified for exteriors and is of good quality. Make sure that you use similarly based paints together, such as putting a new oil-based paint over an old one. Likewise, match water-based or latex paints together when putting a new coat over an old one. Oil-based products are perfect for trim because of their longevity, but they should not be applied to decks or outdoor flooring, because it gets slippery in inclement weather.

TIP! Consider installing a shower if there is not one in your home already. Showers are more accessible than tubs. Instead of going it alone in the vast world of home improvement, hit up your relatives and friends for advice. If you delay asking for help until the project has already begun, it might be hard to get someone to help. You might have a hard time finishing on time, which would add more stress.

TIP! If the cabinets in your kitchen need to be refinished and you do not have the funds, consider refacing them as opposed to replacing them. It can be very expensive to replace kitchen cabinetry.

Re-caulking the windows in your home will help you save on utility bills. This will ensure that no moisture or drafts leak through from the outside, preventing mold growth and reducing your heating bills. If your caulking is cracked, you can remove it by taking a chisel to it and replacing it.

TIP! Re-decorate your bathroom easily and cheaply. Buying new towels, a shower curtain, and a bath mat is a very easy way to give your bathroom a new look.

Devise a plan for getting rid of your debris. Home improvement projects, mainly those that require some kind of large improvement, make a lot of trash that can get in the way if you’re not sure where you’re going to put it before starting. Lease a dumpster or find someone who has a large truck to help you clear the debris out so you can continue.

TIP! If considering a wood-burning fireplace, consider the downside. Compared with other systems, a wood-burning fireplace retains heat far less efficiently.

As this article already said, home improvement is a great thing for anyone to do. While it’s good to be an expert at home improvements, knowing basic information is helpful. Keep all of the tips fresh in the front of your mind and start chopping away at the needed jobs once they’ve had time to soak.

Thank you for dropping by our electrical services website. We are an extremely reliable and skilled service company and we consider every job and call we get to be the most important because we are aware of the significance of an urgent situation resulting from any power, plumbing system, and/or HVAC trouble you may have. We take pride in our job and feel strongly about building relationships with our customers. We have many completely satisfied and repeat patrons, and would love to include you in our long list of pleased customers. We give 24-hour repair service. It doesn’t matter if it’s regular maintenance or emergency repairs, We will send expert, reliable specialists to fix it promptly! With the high price of today’s devices and equipment systems, you need to have assurance in your repair service provider. We deliver premier quality, trusted repair solutions for your business systems. You can trust our qualified specialists to fix it swiftly and repair it properly. Our success is attributed to our professional personnel and the excellent customer care we give. Our strongest and most important resources are our team players: our staff is what makes us fantastic. Our business is organized to satisfy the repair and installment requirements of today’s customers. Our intention is to be THE BEST IN THE SERVICE INDUSTRY. Our aim is to give the highest possible quality of work and ensure that our clients receive exceptional service.


TIP! Before you start your DIY home improvement tasks, be sure to make a step-by-step list of what it will take to accomplish each part of your plan. Also, seek out advice from someone who knows about these sorts of things in order for you to get the most out of the project.

So, you decided that you want to start improving your home. That is great! There is a lot of hard work involved to improve your home properly. Do you have all of the correct information to do the job correctly? If you do not, you need to read the tips in this article.

TIP! Ask a clerk or manager about discounting supplies you will be needing, at their supply or home improvement store. Sometimes discontinued items can be had for a good price.

When you’re looking for some help with a home improvement project, try to have a backup in case your go-to helpers aren’t all that helpful. As the famous saying dictates, never put your eggs in 1 basket. This can help you to improve the chance for success during your project.

TIP! You need to give a thought to the context of your neighborhood before you engage in extensive remodeling work. If your home is the only Victorian in a neighborhood of saltbox cottages, it will look out of place.

When you think of home improvements, consider how long any new appliances you buy will last. Refrigerators generally last twenty years or longer, but washers and dryers have a life span of just over ten years. Therefore, whenever you perform any renovation to your home, you should carefully select your appliances.

TIP! Before you begin your home improvements, devise a solid plan. Before starting your project, it is best to have all your costs mapped out along with the time it should take you.

Free up some space on your nightstands and end tables by choosing a floor lamp instead of a table lamp. These free-standing lamps are easy to move around, whereas table lamps require lots of surface space. Pick a lamp that has a good design that you could appreciate.

TIP! Cover your floors while painting. Doing so can prevent paint from staining floors or carpets.

People think their houses will sell for more if they install a new central vacuuming system or underfloor radiant heating. Meanwhile, they forget to paint the exterior of the home or repair the shutters that hang crooked. Potential buyers are sure to notice these issues and will leave your home thinking it is a handyman’s special. Keep in mind that the first impression of your home is important.

TIP! Keep trees and shrubs from being too close to your home. Their roots could cause issues with the foundation of your house.

If you are looking to make improvements to your home and don’t know how to do it, these tips should put you on the right path. This is good news! If you still feel puzzled, you may find it helpful to reread this list of tips.

Thank you for checking out our electrical services website. We are a very dependable and experienced company and handle every job and phone call we receive as it is the most important because we understand the significance of an urgent situation resulting from any electrical, plumbing system, and/or HVAC problem you may have. We take pride in our work and feel strongly about establishing partnerships with our customers. We have many satisfied and repeat patrons, and would like to include you in our long list of happy consumers. We provide 24-hour repair service. It doesn’t matter if it’s standard service or critical repairs, we will dispatch skilled, trustworthy specialists to take care of it swiftly! With the high price of today’s appliances and equipment systems, you need to have assurance in your repair specialist. We deliver top-quality, trustworthy repair solutions for your company systems. You can trust our qualified experts to fix it quickly and fix it right. Our success is attributed to our skilled workers and the outstanding customer care we supply. Our greatest and most valued assets are our team players: our workers are what makes us great. Our firm is organized to fulfill the repair and installment demands of today’s clients. Our aim is to be THE BEST IN THE SERVICE MARKET. Our aim is to supply the best quality of work and ensure that our clients get excellent service.




Solar energy is the light and the heat from the sun. Solar energy is free and its supplies are unlimited. There is no air and water pollution caused by using solar energy. But there are still some impacts on the environment, although indirect. Photovoltaic cells used to convert sunlight into electricity use silicon and also produce some waste materials. There are also large solar thermal farms and these farms can also be harmful to the environment and desert ecosystems if not properly managed. Solar energy can be used in different aspects. Solar energy can be used in agriculture. Greenhouses (which are entirely different from greenhouse gases) convert solar light to heat to maximize enhancing the growth of plants and crops. Greenhouses have been around since Roman times, and modern greenhouses were built in Europe in the 16th century.

Greenhouses are still an important part of horticulture nowadays. Daylight systems are also being used to maximize the energy released by the sun. It is used to provide interior illumination, replacing artificial lighting. Daylight systems include sawtooth roofs, light shelves, skylights, and light tubes. Daylight systems, when they are properly implemented, can reduce lighting-related energy consumption by 25 percent.

Solar energy can also be developed into solar thermal technologies, which can be used for water heating, space heating, space cooling, and process heat generation. Solar energy can also be used to distill water and make saline or brackish water potable or drinkable. Solar water disinfection, or SODIS, involves exposing water-filled plastic polyethylene terephthalate or PET bottles. This process takes a long time since the exposure time varies on the weather conditions. It requires a minimum of six hours to two days during days with overcast conditions. Currently, there are two million people in developing centuries use SODIS for their daily drinking water needs.

Also, sunlight can be converted into electricity using photovoltaics or PV. PV has been mainly used to power small and medium-sized things like a calculator powered by a single solar cell. There are homes powered by photovoltaics. Using solar energy for water and space heating is the most widely used application of solar energy. While ventilation and solar air heating are also growing in popularity.

There are three main ways to use solar energy. The main way of using and converting solar energy is by using solar cells. Solar cells convert light directly into electricity. Solar cells are also called photovoltaic or photoelectric cells. Meanwhile, solar furnaces use a huge array of mirrors to concentrate on the Sun’s energy in a small space and produce very high temperatures. Solar furnaces are also called solar cookers. A solar cooker can be used in hot countries to cook food. With all the benefits of using solar energy, there is still a downside to this alternative energy source. It does not work during nighttime. The cost of setting up solar stations is expensive, but the benefit of using solar energy when accumulated is so much more.



Electrical Contractor

A seasoned electrical contractor can make all the difference when you find yourself in need of wiring services. At our electric services company, we put our experience to work for you, and we’re committed to accuracy in every task we take on. Locally owned and operated, we’re proud to lend our electrical knowledge to our community. No matter the size or extent of your wiring demands, we’re up for any challenge.

High-Quality Services
Arriving promptly and prepared for the business at hand, we’ll assess your wiring requirements and devise a strategy. From telephone and cable outlet installation to home theatre wiring or short circuit repair, we’ll go out of our way to get the job done right.

When you’re ready to hire an electrical contractor, look no further than our company.



1/4/24 electrical – gtg





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Conservation Of Charge
Not only was Benjamin Franklin the first to recognize positive and
negative charges, but also that electricity is an energy that is
captured, not created. This is a principle known as the
“conservation of charge. ”

There is a saying that “Faith is like electricity. You can’t see
it, but you can see the light. ” You can have faith that we’ll keep
your lights working!

Lightning Fish
It’s apparent that as early as the 15th century, connections were
made between lightning and the discharges from electric fish. Arabs
named the electric ray “raad, ” which was their word for lightning.

For Those About To Sew…
Did you know that the Australian rock band AC/DC got their name
from a label on their sister’s sewing machine? (In those days, some
regions supplied AC electricity while other areas had DC, so many
appliances specified what they could handle. )

Ain’t Superstitious
The words “electric” and “electricity” first appeared in print in
Thomas Browne’s 1646 publication, Pseudodoxia Epidemica, or Vulgar
Errors, a work that refuted the common superstitions and errors of
his time.

Rubbing Amber
Curious ancient Greeks used to experiment with amber and
discovered that rubbing it long enough would produce electric
sparks. Thus, the word “electricity” derives from the Greek word
for amber, which is “electron. ”

A Penny For A Laugh
“Electricity can be dangerous. My nephew tried to stick a penny
into a plug. Whoever said a penny doesn’t go far didn’t see him
shoot across that floor. I told him he was grounded. ” ~ Tim Allen

“If it weren’t for electricity we’d all be watching television by
candlelight. ” ~ George Goba

Cycle Breaker Boxes
To avoid corrosion, it is a good practice to turn the breakers in
your breaker box off and on at least once a year.


Commercial Electrical Contractors – Installation, Service & Repair
For more then 30 years, our company has brought a new standard of professionalism and performance to a wide variety of commercial electrical contracting projects throughout the Southeast of the United States. From schools to multifamily homes to office buildings, we have the capability to design and complete the commercial electrical project you need!

Providing Simple to Complex Commercial Electrical Contracting Services
Our company offers a full line of commercial electrical project services, including design, repair, and maintenance. Our full-service approach and extensive experience have proven time and time again why we are the leaders in the commercial electrical service industry. With an exceptional reputation in the industry, we have designed and completed numerous complex and unique projects to date.

Please take a look at our past Commercial Electrical Projects:
New Commercial Buildings
Tenant Buildouts
Value Engineering Projects
Bucket Truck Work
24-hour Service
Surge Protection
Copy Machine Circuits
Parking Lot Lighting
Sub-panel Additions
Lamp and Ballast
Green Lighting
Free Estimates
Dedicated Computer
Meter Can Repairs


We are an incredibly reliable and expert Service Company and treat every job and phone call we get like it is the most important because we recognize the implication of an unexpected emergency resulting from any electrical, plumbing system, and/or HVAC trouble you may have. We take pride in our work and believe highly in developing partnerships with our clients. We have numerous pleased and repeat patrons, and would love to include you in our extensive list of pleased customers. We give 24-hour repair service. It doesn’t matter if it’s standard service or unexpected repairs, we will send highly trained, trustworthy technicians to take care of it swiftly! With the high cost of today’s devices and equipment systems, you need to have assurance in your repair company. We supply premier quality, reliable repair solutions for your company systems. You can trust our educated technicians to fix it quickly and take care of it properly. Our success is attributed to our qualified staff and the superb client care we provide. Our greatest and most valuable resources are our team players: our staff is what makes us exceptional. Our firm is organized to meet the repair and installation requirements of today’s clients. Our goal is to be THE BEST IN THE SERVICE BUSINESS. Our objective is to provide the greatest quality of work and guarantee that our consumers get excellent service.


We are a very reliable and professional Service Company and treat every job and call we receive like it is the most important because we understand the significance of an emergency resulting from any electrical, plumbing, and/or HVAC issue you may have. We take pride in our work and believe strongly in building relationships with our customers. Call Us First For Quality & Customer Satisfaction Guaranteed Service Specialists

Well-trained & Educated Emergency Service Available Pride in workmanship. We have many satisfied and repeat customers and would love to include you in our long list of satisfied customers. We offer 24-hour repair service. It doesn’t matter if it’s routine maintenance or emergency repairs, we will send experienced, reliable technicians to fix it fast! With the high cost of today’s appliances and equipment systems, you need to have confidence in your repair provider. We offer top-quality, dependable repair services for your business systems. You can trust our trained technicians to fix it fast and fix it right. Our success is attributed to our expert staff and the excellent customer care we provide. Our strongest and most valuable assets are our team players: our staff is what makes us great. Our company is organized to meet the repair and installation needs of today’s customers. Our objective is to be THE BEST IN THE SERVICE INDUSTRY. Our goal is to provide the highest quality of work and ensure that our customers receive excellent service.

Master Electrical Technicians at your service! We provide solutions for your electrical and wiring projects. Our services cover everything from residential to commercial, interior/exterior, new wiring, electrical maintenance and troubleshooting. No matter what your electrical needs are, we have the right solution, at the right price.

Professional Plumbing Services you can COUNT ON! Not only will you encounter expertly trained plumbing technicians, but also technicians who are trained to deliver a tailored and unique service experience. This experience includes treating you and your home with respect. Many of our customers look to us as their preferred plumbing service provider.

Heating, Ventilating, and Air Conditioning Residential & Commercial Sales Service & Installation
We offer installation, service, and repair for both Residential and Commercial buildings, 24 hours/7 days, and Emergency Service. We can handle all of your heating, ventilation and air conditioning needs, from the smallest repair to complete installations. We work on all makes & models and guarantee your satisfaction when we are done. We offer 24-hour emergency service, reasonable rates, and Free Estimates on installations. Call us when you need service on Heat Pumps, Gas, Oil, Hot Water or Electric Heat, Humidifiers, Air Cleaners, Gas Boilers, and more. We can promise that you are getting the best job done and the best prices possible. Power Plus Services offers top-quality, dependable repair service for your home and business systems. You can trust our trained technicians to fix it fast and fix it right.

Our company is dedicated to providing you with the best available service and a 1 hour RESPONSE Time. We use modern methods to achieve the highest standards of safety and productivity. If, for any reason, you are not satisfied with our work, we will return to re-diagnose and repair, if necessary, at no additional cost. Customer satisfaction is important to us. We are fully committed to working with you 100%. We are fully licensed and bonded. We are also fully insured with liability insurance of $1,000,000.


Lighting or illumination is the deliberate application of light to achieve some aesthetic or practical effect. Lighting includes the use of both artificial light sources such as lamps and natural illumination of interiors from daylight. Daylighting (through windows, skylights, etc. ) is often used as the main source of light during daytime in buildings given its low cost. Artificial lighting represents a major component of energy consumption, accounting for a significant part of all energy consumed worldwide. Artificial lighting is most commonly provided today by electric lights, but gas lighting, candles, or oil lamps were used in the past, and still are used in certain situations. Proper lighting can enhance task performance or aesthetics, while there can be energy wastage and adverse health effects of poorly designed lighting. Indoor lighting is a form of fixture or furnishing and a key part of interior design. Lighting can also be an intrinsic component of landscaping. Lighting fixtures come in a wide variety of styles for various functions. The most important functions are as a holder for the light source, to provide directed light and to avoid visual glare. Some are very plain and functional, while some are pieces of art in themselves. Nearly any material can be used, so long as it can tolerate the excess heat and is in keeping with safety codes. An important property of light fixtures is the luminous efficacy or wall-plug efficiency, meaning the amount of usable light emanating from the fixture per used energy, usually measured in lumen per watt. A fixture using replaceable light sources can also have its efficiency quoted as the percentage of light passed from the “bulb” to the surroundings. The more transparent the lighting fixture is, the higher its efficacy. Shading the light will normally decrease efficacy but increase the directionality and the visual comfort probability. Lighting is classified by intended use as general, localized, or task lighting, depending largely on the distribution of the light produced by the fixture. Task lighting is mainly functional and is usually the most concentrated, for purposes such as reading or inspection of materials. For example, reading poor-quality reproductions may require task lighting levels up to 1500 lux (150 footcandles), and some inspection tasks or surgical procedures require even higher levels. Accent lighting is mainly decorative and intended to highlight pictures, plants, or other elements of interior design or landscaping. General lighting (sometimes referred to as ambient light fills in between the two and is intended for general illumination of an area. Indoors, this would be a basic lamp on a table or floor or a fixture on the ceiling. Outdoors, general lighting for a parking lot may be as low as 10-20 lux (1-2 footcandles) since pedestrians and motorists already used to the dark will need little light for crossing the area. Downlighting is most common, with fixtures on or recessed in the ceiling casting light downward. This tends to be the most used method, used in both offices and homes. Although it is easy to design, it has dramatic problems with glare and excess energy consumption due to a large number of fittings. Uplighting is less common, often used to bounce indirect light off the ceiling and back down. It is commonly used in lighting applications that require minimal glare and uniform general illuminance levels. Uplighting (indirect) uses a diffuse surface to reflect light in a space and can minimize disabling glare on computer displays and other dark glossy surfaces. It gives a more uniform presentation of the light output in operation. However indirect lighting is completely reliant upon the reflectance value of the surface. While indirect lighting can create a diffused and shadow-free light effect, it can be regarded as an uneconomical lighting principle. Front lighting is also quite common but tends to make the subject look flat as it casts almost no visible shadows. Lighting from the side is less common, as it tends to produce glare near eye level. Backlighting either around or through an object is mainly for accent. Forms of lighting include alcove lighting, which, like most other uplighting, is indirect. This is often done with fluorescent lighting or rope light, or occasionally with neon lighting. It is a form of backlighting. Soffit or close-to-wall lighting can be general or a decorative wall wash, sometimes used to bring out texture (like stucco or plaster) on a wall, though this may also show its defects as well. The effect depends heavily on the exact type of lighting source used. Recessed lighting (often called “pot lights,” “can lights,” or ‘high hats”) is popular, with fixtures mounted into the ceiling structure so as to appear to flush with it. These downlights can use narrow beam spotlights, or wider-angle floodlights, both of which are bulbs having their own reflectors. There are also downlights with internal reflectors designed to accept common ‘A’ lamps (light bulbs) which are generally less costly than reflector lamps. Downlights can be incandescent, fluorescent, HID (high-intensity discharge), or LED. Track lighting, invented by Lightolier, was popular at one point because it was much easier to install than recessed lighting, and individual fixtures are decorative and can be easily aimed at a wall. It has regained some popularity recently in low-voltage tracks, which often look nothing like their predecessors because they do not have the safety issues that line-voltage systems have, and are therefore less bulky and more ornamental in themselves. A master transformer feeds all of the fixtures on the track or rod with 12 or 24 volts, instead of each light fixture having its own line-to-low voltage transformer. There are traditional spots and floods, as well as other small hanging fixtures. A modified version of this is cable lighting, where lights are hung from or clipped to bare metal cables under tension. A sconce is a wall-mounted fixture, particularly one that shines up and sometimes down as well. A torchiere is an uplight intended for ambient lighting. It is typically a floor lamp but may be wall-mounted like a sconce. The portable or table lamp is probably the most common fixture, found in many homes and offices. The standard lamp and shade that sits on a table is general lighting, while the desk lamp is considered task lighting. Magnifier lamps are also task lighting. The illuminated ceiling was once popular in the 1960s and 1970s but fell out of favor after the 1980s. This uses diffuser panels hung like a suspended ceiling below fluorescent lights, and is considered general lighting. Other forms include neon, which is not usually intended to illuminate anything else but to actually be an artwork in itself. This would probably fall under accent lighting, though in a dark nightclub, it could be considered general lighting. In a movie theater, each step in the aisles is usually marked with a row of small lights for convenience and safety when the film has started. Hence, the other lights are off. Traditionally made up of small low-wattage, low-voltage lamps in a track or translucent tube, these are rapidly being replaced with LED-based versions. Street Lights are used to light roadways and walkways at night. Some manufacturers are designing LED and photovoltaic luminaires to provide an energy-efficient alternative to traditional street light fixtures. Floodlights can be used to illuminate outdoor playing fields or work zones during nighttime hours. The most common types of floodlights are metal halide and high-pressure sodium lights. Beacon lights are positioned at the intersection of two roads to aid in navigation. Security lights can be used along roadways in urban areas, or behind homes or commercial facilities. These are extremely bright lights used to deter crime. Security lights may include floodlights. Entry lights can be used outside to illuminate and signal the entrance to a property. These lights are installed for safety, security, and for decoration. Underwater accent lighting is also used for koi ponds, fountains, swimming pools and the like. Commonly called ‘light bulbs,’ lamps are the removable and replaceable portion of a luminaire that converts electrical energy to both visible and non-visible electromagnetic energy.

Specialists who work with lighting carefully avoid energetic units for measuring the light output of sources of light due to the spectral response of human visual perception. For example, instead of watt per steradian, the special unit candela is used; 1 candela=(1/683) W/steradian for monochromatic light at 555 nmwavelength. Common characteristics used to evaluate lamp quality include efficacy measured in lumens per watt, typical lamp life measured in hours, and Color Rendering Index on a scale of 0 to 100. The cost of replacement lamps is also an important factor in any design. Lighting design, as it applies to the built environment, also known as ‘architectural lighting design,’ is both a science and an art. Comprehensive lighting design requires consideration of the amount of functional light provided, the energy consumed, as well as the aesthetic impact supplied by the lighting system. Some buildings, like surgical centers and sports facilities, are primarily concerned with providing the appropriate amount of light for the associated task. Some buildings, like warehouses and office buildings, are primarily concerned with saving money through the energy efficiency of the lighting system. Other buildings, like casinos and theatres, are primarily concerned with enhancing the appearance and emotional impact of architecture through lighting systems. Therefore, it is important that the sciences of light production and luminaire photometrics are balanced with the artistic application of light as a medium in our built environment. These electrical lighting systems should also consider the impacts of, and ideally be integrated with, daylighting systems. Factors involved in lighting design are essentially the same as those discussed above in energy conservation analysis.

For simple installations, hand calculations based on tabular data can be used to provide an acceptable lighting design. More critical or optimized designs now routinely use mathematical modeling on a computer. Based on the positions and mounting heights of the fixtures, and their photometric characteristics, the proposed lighting layout can be checked for uniformity and quantity of illumination. For larger projects or those with irregular floor plans, lighting design software can be used. Each fixture has its location entered, and the reflectance of walls, ceiling, and floors can be entered. The computer program will then produce a set of contour charts overlaid on the project floor plan, showing the light level to be expected at the working height. More advanced programs can include the effect of light from windows or skylights, allowing further optimization of the operating cost of the lighting installation. The Zonal Cavity Method is used as a basis for both hand, tabulated, and computer calculations. This method uses the reflectance coefficients of room surfaces to model the contribution to useful illumination at the working level of the room due to light reflected from the walls and the ceiling. Simplified photometric values are usually given by fixture manufacturers for use in this method. Computer modeling of outdoor flood lighting usually proceeds directly from photometric data. The total lighting power of a lamp is divided into small solid angular regions. Each region is extended to the surface that is to be lit, and the area is calculated, giving the light power per unit of area. Where multiple lamps are used to illuminate the same area, each one’s contribution is summed. Again, the tabulated light levels (in lux or foot candles) can be presented as contour lines of constant lighting value overlaid on the project plan drawing. Hand calculations might only be required at a few points, but computer calculations allow a better estimate of the uniformity and lighting level. Practical lighting design must take into account the gradual decrease in light levels from each lamp owing to lamp aging, lamp burnout, and dirt accumulation on fixtures and lamp surfaces. Empirically established depreciation factors are listed in lighting design handbooks. Luminance is a photometric measure of the density of luminous intensity in a given direction. It describes the amount of light that passes through or is emitted from a particular area and falls within a given solid angle. The SI unit for luminance is candela per square meter (cd/m2). The CGS unit of luminance is the stilb, which is equal to one candela per square centimeter or 10A kcd/m2. To define light source color properties, the lighting industry predominantly relies on two metrics, correlated color temperature (CCT), commonly used as an indication of the apparent aswarmthat or ascoolnessat of the light emitted by a source, and color rendering index (CRI), an indication of the light source’s ability to make objects appear natural. However, these two metrics, developed in the last century, are facing increased challenges and criticisms as new types of light sources, particularly light-emitting diodes (LEDs), become more prevalent in the market. For example, in order to meet the expectations for good color rendering in retail applications, research suggests using the well-established CRI along with another metric called gamut area index (GAI). GAI represents the relative separation of object colors illuminated by a light source; the greater the GAI, the greater the apparent saturation or vividness of the object colors. As a result, light sources that balance both CRI and GAI are generally preferred over ones that have only high CRI or only high GAI. Typical measurements of light have used a Dosimeter. Dosimeters measure an individual’s or an object’s exposure to something in the environment, such as light dosimeters and ultraviolet dosimeters.

In order to specifically measure the amount of light entering the eye, a personal circadian light meter called the Daysimeter has been developed. This is the first device created to accurately measure and characterize light (intensity, spectrum, timing, and duration) entering the eye that affects the human body’s clock. The device is a small, head-mounted device that measures an individual’s daily rest and activity patterns, as well as exposure to circadian light, particularly natural light from the blue sky that stimulates the circadian system. The device measures activity and light together at regular time intervals and electronically stores and logs its operating temperature. The Daysimeter can gather data for up to 30 days for analysis. Artificial lighting consumes a significant part of all electrical energy consumed worldwide. In homes and offices from 20 to 50 percent of total energy consumed is due to lighting. Most importantly, for some buildings over 90 percent of lighting energy consumed can be an unnecessary expense through over-illumination. The cost of that lighting can be substantial. A single 100 W light bulb used just 6 hours a day can cost over $25 per year to use (.12/kWh). Thus lighting represents a critical component of energy use today, especially in large office buildings where there are many alternatives for energy usage in lighting. There are several strategies available to minimize energy requirements in any building: Specification of illumination requirements for each given use area. Analysis of lighting quality to ensure that adverse components of lighting (for example, glare or incorrect color spectrum) are not biasing the design. Integration of space planning and interior architecture (including choice of interior surfaces and room geometries) to lighting design. Design of time of day use that does not expend unnecessary energy. Selection of fixture and lamp types that reflect the best available technology for energy conservation. Training of building occupants to use lighting equipment in the most efficient manner. Maintenance of lighting systems to minimize energy wastage. 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. 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. It is valuable to provide the correct light intensity and color spectrum for each task or environment. Otherwise, energy not only could be wasted but over-illumination can lead to adverse health and psychological effects. Specification of illumination requirements is the basic concept of deciding how much illumination is required for a given task. Clearly, much less light is required to illuminate a hallway or bathroom compared to that needed for a word-processing workstation.

Prior to 1970 (and too often even today), a lighting engineer would simply apply the same level of illumination design to all parts of the building without considering usage. Generally speaking, the energy expended is proportional to the design illumination level. For example, a lighting level of 80 footcandles might be chosen for a work environment involving meeting rooms and conferences, whereas a level of 40 footcandles could be selected for building hallways. If the hallway standard simply emulates the conference room needs, then twice the amount of energy will be consumed as is needed for hallways. Unfortunately, most of the lighting standards even today have been specified by industrial groups who manufacture and sell lighting, so a historical commercial bias exists in designing most building lighting, especially for office and industrial settings. Beyond the energy factors being considered, it is important not to over-design illumination, lest adverse health effects such as headache frequency, stress, and increased blood pressure be induced by the higher lighting levels. In addition, glare or excess light can decrease worker efficiency. Analysis of lighting quality particularly emphasizes the use of natural lighting but also considers spectral content if artificial light is to be used. Not only will greater reliance on natural light reduce energy consumption, but will favorably impact human health and performance.

New studies have shown that the performance of students is influenced by the time and duration of daylight in their regular schedules. Designing school facilities to incorporate the right types of light at the right time of day for the right duration may improve student performance and well-being. Similarly, designing lighting systems that maximize the right amount of light at the appropriate time of day for the elderly may help relieve symptoms of Alzheimer’s Disease. The human circadian system is entrained to a 24-hour light-dark pattern that mimics the earth’s natural light/dark pattern. When those patterns are disrupted, they disrupt the natural circadian cycle. Circadian disruption may lead to numerous health problems including breast cancer, seasonal affective disorder, delayed sleep phase syndrome, and other ailments.

In 1849, Dr. Abraham Gesner, a Canadian geologist, devised a method where kerosene could be distilled from petroleum. Earlier coal-gas methods had been used for lighting since the 1820s, but they were expensive. Gesner’s kerosene was cheap, easy to produce, could be burned in existing lamps, and did not produce an offensive odor as did most whale oil. It could be stored indefinitely, unlike whale oil, which would eventually spoil. The American petroleum boom began in the 1850s. By the end of the decade, there were 30 kerosene plants operating in the United States. The cheaper, more efficient fuel began to drive whale oil out of the market. John D. Rockefeller was most responsible for the commercial success of kerosene. He set up a network of kerosene distilleries, which would later become Standard Oil, thus completely abolishing the need for whale oil lamps.

Compact fluorescent lamps (aka ‘CFLs’) use less power to supply the same amount of light as an incandescent lamp. Due to the ability to reduce electric consumption, many organizations have undertaken measures to encourage the adoption of CFLs. Some electric utilities and local governments have subsidized CFLs or provided them free to customers as a means of reducing electric demand. For a given light output, CFLs use between one-fifth and one-quarter of the power of an equivalent incandescent lamp. One of the simplest and quickest ways for a household or business to become more energy efficient is to adopt CFLs as the main lamp source, as suggested by the Alliance for Climate Protection.

LED lamps have been advocated as the newest and best environmental lighting method. According to the Energy Saving Trust, LED lamps use only 10% power compared to a standard incandescent bulb, where compact fluorescent lamps use 20% and energy saving halogen lamps 70%. A downside is still the initial cost, which is higher than that of compact fluorescent lamps. However, when the life expectancy and other factors are incorporated, regular LEDs are not more costly than CFL lamps. General Electric began producing organic LEDs for architectural use in 2010.

From a military standpoint, lighting is a critical part of the battlefield conditions. Shadows are good places to hide, while bright areas are more exposed. It is often beneficial to fight with the Sun or other light source behind you, giving your enemy a disturbing visual glare and partially hiding your own movements in the backlight. If natural light is not present searchlights and flares can be used. However, the use of light may disclose your own hidden position and modern warfare has seen increased use of night vision through the use of infrared cameras and image intensifiers. Flares can also be used by the military to mark positions, usually for targeting, but laser-guided and GPS weapons have eliminated this need for the most part.

The International Commission on Illumination (CIE) is an international authority and standard-defining organization on color and lighting. Publishing widely used standard metrics such as various CIE color spaces and the color rendering index. The Illuminating Engineering Society of North America (IESNA), in conjunction with organizations like ANSI and ASHRAE, publishes guidelines, standards, and handbooks that allow the categorization of the illumination needs of different built environments. Manufacturers of lighting equipment publish photometric data for their products, which defines the distribution of light released by a specific luminaire. This data is typically expressed in a standardized form defined by the IESNA. The International Association of Lighting Designers (IALD) is an organization that focuses on the advancement of lighting design education and the recognition of independent professional lighting designers. Those fully independent designers who meet the requirements for professional membership in the association typically append the abbreviation IALD to their name.

The Professional Lighting Designers Association (PLDA), formerly known as ELDA is an organization focusing on the promotion of the profession of Architectural Lighting Design. They publish a monthly newsletter and organize different events throughout the world. The National Council on Qualifications for the Lighting Professions (NCQLP) offers the Lighting Certification Examination which tests rudimentary lighting design principles. Individuals who pass this exam become Lighting Certified and may append the abbreviation LC to their name. This certification process is one of three national (U. S. ) examinations (the others are CLEP and CLMC) in the lighting industry and is open not only to designers, but to lighting equipment manufacturers, electric utility employees, etc. Generally speaking, there is no legal or practical requirement for the lighting design team to possess the certifications discussed.

The Professional Lighting And Sound Association (PLASA) is a trade organization representing 500+ individual and corporate members drawn from the technical services sector. Its members include manufacturers and distributors of stage and entertainment lighting, sound, rigging and similar products and services, and affiliated professionals in the area. They lobby for and represent the interests of the industry at various levels, interacting with government and regulating bodies and presenting the case for the entertainment industry. Example subjects of this representation include the ongoing review of radio frequencies (which may or may not affect the radio bands in which wireless microphones and other devices are used) and engaging with the issues surrounding the introduction of the RoHS (Restriction of Hazardous Substances Directive) regulations.

The electrical power industry provides the production and delivery of electrical power (electrical energy), often known as power, or electricity, in sufficient quantities to areas that need electricity through a grid. Many households and businesses need access to electricity, especially in developed nations, the demand being scarcer in developing nations. Demand for electricity is derived from the requirement for electricity in order to operate domestic appliances, office equipment, and industrial machinery and provide sufficient energy for both domestic and commercial lighting, heating, cooking, and industrial processes. Because of this aspect of the industry, it is viewed as a public utility as infrastructure.

The electrical power industry is commonly split up into four processes. These are electricity generation such as a power station, electric power transmission, electricity distribution and electricity retailing. In many countries, electric power companies own the whole infrastructure from generating stations to transmission and distribution infrastructure. For this reason, electric power is viewed as a natural monopoly. The industry is generally heavily regulated, often with price controls and is frequently government-owned and operated. The nature and state of market reform of the electricity market often determine whether electric companies are able to be involved in just some of these processes without having to own the entire infrastructure or whether citizens choose which components of infrastructure to patronize. In countries where electricity provision is deregulated, end-users of electricity may opt for less costly green electricity.

All forms of electricity generation have positive and negative aspects. Technology will probably eventually declare the most preferred forms, but in a market economy, the options with less overall costs generally will be chosen above other sources. It is not clear yet which form can best meet the necessary energy demands or which process can best solve the demand for electricity. There are indications that renewable energy and distributed generation are becoming more viable in economic terms. A diverse mix of generation sources reduces the risks of electricity price spikes. Although electricity had been known to be produced as a result of the chemical reactions that take place in an electrolytic cell since Alessandro Volta developed the voltaic pile in 1800, its production by this means was, and still is, expensive. In 1831, Michael Faraday devised a machine that generated electricity from rotary motion, but it took almost 50 years for the technology to reach a commercially viable stage. In 1878, in the US, Thomas Edison developed and sold a commercially viable replacement for gas lighting and heating using locally generated and distributed direct current electricity. The world’s first public electricity supply was provided in late 1881 when the streets of the Surrey town of Godalming in the UK were lit with electric light. This system was powered by a water wheel on the River Wey, which drove a Siemens alternator that supplied a number of arc lamps within the town. This supply scheme also provided electricity to a number of shops and premises. Coinciding with this, in early 1882, Edison opened the world’s first steam-powered electricity generating station at Holborn Viaduct in London, where he had entered into an agreement with the City Corporation for a period of three months to provide street lighting. In time he had supplied a number of local consumers with electric light. The method of supply was direct current (DC). It was later on in the year, in September 1882, that Edison opened the Pearl Street Power Station in New York City, and again, it was a DC supply. It was for this reason that the generation was close to or on the consumer’s premises as Edison had no means of voltage conversion. The voltage chosen for any electrical system is a compromise. Increasing the voltage reduces the current and, therefore, reduces resistive losses in the cable. Unfortunately, it increases the danger from direct contact and also increases the required insulation thickness. Furthermore, some load types were difficult or impossible to make for higher voltages.

Additionally, Robert Hammond, in December 1881, demonstrated the new electric light in the Sussex town of Brighton in the UK for a trial period. The ensuing success of this installation enabled Hammond to put this venture on both a commercial and legal footing, as a number of shop owners wanted to use the new electric light. Thus the Hammond Electricity Supply Co. was launched. While the Godalming and Holborn Viaduct Schemes closed after a few years the Brighton Scheme continued on, and supply was in 1887 made available for 24 hours per day. Nikola Tesla, who had worked for Edison for a short time and appreciated the electrical theory in a way that Edison did not, devised an alternative system using alternating current. Tesla realized that while doubling the voltage would halve the current and reduce losses by three-quarters, only an alternating current system allowed the transformation between voltage levels in different parts of the system. This allowed efficient high voltages for distribution where their risks could easily be mitigated by good design while still allowing fairly safe voltages to be supplied to the loads. He went on to develop the overall theory of his system, devising theoretical and practical alternatives for all of the direct current appliances then in use, and patented his novel ideas in 1887, in thirty separate patents. In 1888, Tesla’s work came to the attention of George Westinghouse, who owned a patent for a type of transformer that could deal with high power and was easy to make. Westinghouse had been operating an alternating current lighting plant in Great Barrington, Massachusetts since 1886. While Westinghouse’s system could use Edison’s lights and had heaters, it did not have a motor. With Tesla and his patents, Westinghouse built a power system for a gold mine in Telluride, Colorado, in 1891, with a water-driven 100 horsepower (75A kW) generator powering a 100 horsepower (75A kW) motor over a 2.5-mile (4A km) power line. Almarian Decker finally invented the whole system of three-phase power generating in Redlands, California in 1893. Then, in a deal with General Electric, which Edison had been forced to sell, Westinghouse’s company went on to construct the Adams Power Plant at Niagara Falls, with three 5,000 horsepower (3.7 MW) Tesla generators supplying electricity to an aluminum smelter at Niagara and the town of Buffalo 22 miles (35A km) away. The Niagara power station commenced operation on April 20, 1895. Tesla’s alternating current system remains the primary means of delivering electrical energy to consumers throughout the world.

While high-voltage direct current (HVDC) is increasingly being used to transmit large quantities of electricity over long distances or to connect adjacent asynchronous power systems, the bulk of electricity generation, transmission, distribution and retailing takes place using alternating current. There has been a movement towards separating the monopoly parts of the industry, such as transmission and distribution sectors from the contestable sectors of generation and retailing across the world. This has occurred prominently since the reform of the electricity supply industry in England and Wales in 1990. In some countries, wholesale electricity markets operate, with generators and retailers trading electricity in a similar manner to shares and currency.