How much energy does a normal streetlight use?

Question

Well my class doing a project And we're just wondrering how much energy a normal streetlight uses.

Answer 1

Well...This is a tough question. But I could give you an insight of how its history came about. And perhaps you could applied it in your introduction...

The use of street lighting was first recorded in London in 1417 when Sir Henry Barton, the mayor, ordered lanterns with lights to be hanged out on the winter evenings between Hallowtide and Candlemasse. However it was introduced to the United States by famed inventor Benjamin Franklin, who was the postmaster of Philadelphia, Pennsylvania. Because of this, Philadelphia is regarded by many as the birthplace of street lighting in the United States.

The colonial-era streetlights were lit by candles shining inside their boxes. After the invention of gas light by William Murdoch in 1792, cities in Britain began to light their streets using gas and the United States followed suit shortly afterwards with the introduction of gas lighting to the streets of Baltimore in 1816. Throughout the nineteenth century, the use of gas lighting increased. After Edison pioneered electric use, light bulbs were developed for the streetlights as well. The first city to use electric street lights was Attalla, Alabama (1882).

By the beginning of the 20th century, the number of candle-lit streetlights were dwindling as developers were searching for safer and more effective ways to illuminate their streets. The fluorescent and incandescent lights became very popular during the 1930s and 1940s, when automobile travel began to flourish. A street with lights was referred to as a white way during the early 20th century.
Means of light generation

Incandescent light
By far the most recognized type of lighting, your common household bulb. These were the first low power electric lighting in cities world wide. Some can still be found in streetlight service to this day. Others have been installed popular downtown areas of major cities to have a nostalgia effect. Incandescent light also has excellent CRI rated at 100. Color temp is generally around 2-3K depending on type. Incandescent light is also the most inefficient when compared to HID and gas discharge lighting such as Neon light. About 98% of the energy used by incandescent lighting is wasted in heat.


Arc lamp
Arc lamps were used in the late 19th & early 20th century by many large cities for street lighting. The bright light of Arc lamps required that the early Arc lamps be placed on rather high (60 to 150 foot) towers; as such, they may have been the predecessor to today's high-mast lighting systems, as seen on freeways, expressways and other high-speed divided highways. (They were also widely used in film and stage.) Arc lamps use high current between two electrodes and require substantial maintenance. Arc lights have mainly been used where high lumen light was needed such as lighthouses. Today very few arc lights are in operation for actual light use. Again mainly in lighthouses (few) and industrial uses.


Mercury vapor
In 1948, the first regular production mercury vapor(MV) streetlight assembly was developed. It was deemed a major improvement over the old incandescent light, and shone much brighter than incandescent or fluorescent lights. Initially people disliked them because their bluish-green light made people look like they had their blood drained from them. Other disadvantages are that a significant portion of their light output is ultraviolet — both a waste and a safety hazard if the glass breaks, they "depreciate" — get steadily dimmer and dimmer with age while using the same amount of energy. Mercury lamps were developed in the early/mid 60s coated with a special material made of phosphors inside the bulb to help correct the lack of orange/red light from MV lamps(increasing the CRI). The UV light excites the phosphorus producing a more "white" light (really producing some "reds" in the light spectrum). These are known as "color corrected" lamps. Most go by the "DX" designation on the lamp and have a white appearance to the bulb. They're a major improvement over their "clear bulb" counter parts.

Many towns/cities still have their MV streetlights in operation, though they're slowly being replaced by HPS lamps. Debates still rage whether this is truly a wise move given the maintenance cost and quality issues of HPS lighting.


Sodium vapor
Around 1970, a new streetlight was put into service: The high pressure sodium(HPS) light. It was initially disliked by most residents because of its ugly orange glow, but the sodium vapor streetlight has since become the dominant type on American roadways and most folks have become used to the orange/yellow glow. It is by far the more efficient light source when compared to Mercury Vapor(MV) or Metal Halide (MH). Color Corrected Sodium Vapor Lights exist but are very expensive. These "color corrected" HPS lamps have lower life and are less efficient in lumens output.

There are two types of sodium vapor streetlights: high-pressure(HPS) and low-pressure(LPS). Of the two, HPS is the more-commonly used type, and it is found in many new streetlight fixtures. Sometimes, older (pre-1970) fixtures may be modified to use HPS lights as well. This process is known as retrofitting. Virtually all fixtures that are converted to HPS have previously been lit with mercury vapor. Examples of retrofitted fixtures for HPS use include the GE Form 400 and the second-generation Westinghouse OV-25 Silverliner (although later versions of this model were available from the factory as HPS units).

NOTE: While HPS lamps have been in operation for several decades now, their shortcomings are becoming apparent. Initial intent was to replace all existing street lamps with HPS due to their lower cost and greater efficiency. But there are quality control issues with these lamps (e.g. short life cycle, "cycling" lamps, etc.). This issue has increased overall cost to municipalities when compared to Mercury Vapor.

Note 2: HPS lamps have slightly different electrical requirements than do the older-technology MV lamps. Both HPS and MV lamps require a transformer to raise the voltage of the electricity used to power the fixture. However, HPS lamps also require an electrical "starter" circuit to start--much like the older fluorescent lamps in residential use. MV lamps do not require a "starter". On the other hand, MV lamps slowly dim over time, and a twenty-year-old lamp may emit a very pleasing, but useless, soft glow, rather than the powerful blue-white light of a new MV lamp. On the other hand, the yellow-spectrum HPS lamps are known for "cycling" or intermittent lighting where the lamp cycles on and off. This tendency is most commonly seen in lamps that are reaching the end of their life cycle. The arc within the lamp extinguishes and the lamp must cool down before the starter circuit initializes a new arc.

HPS lamps do not last as long as do MV lamps, but they do give increased light and efficiency. Many prefer the blue-white light of the MV lamp to the orange-yellow light of the HPS lamp.


Metal halide
In recent years, Metal halide lamp(MH) streetlights have illuminated the roadways and parking lots. Metal halide has long become popular in business installations, as it can be found in warehouses, schools, hospitals and office buildings. Unlike the old mercury lights, metal halide casts a true white light. It is not nearly as popular as its sodium or mercury counterparts, as it's newer and less efficient than sodium.

Metal halide lights have also been used for retrofitting. Virtually all fixtures that are converted to metal halide have previously been lit with high-pressure sodium (HPS). Examples of retrofitted fixtures for metal halide use include the Thomas & Betts Model 25 and Model 327, as well as full-cutoff versions of GE's M400. MH lamps suffer color shift as they age though this has been improving. Actual life expectancy is about 10-12K hours on average. There has also been a noted issue with the lamps "exploding/shattering" during a failure. High cost and low life hours has kept them from becoming popular municipal lighting sources even though they have a much improved CRI around 85.


Compact fluorescent lamp
CFL or "compact fluorescent lamp/lighting" has been used more frequently as time has improved the quality of these lamps. These lamps have been used on municipal walkways and street lighting though they are still rare at this time. Improvements in reliability still need to be made. Some issues with them are high heat build up in the self contained ballast, low life/burnout due to frequent cycling(on/off) of the lamp, and the problem where most fluorescent sources become dimmer in cold weather (or fail to start at all). CFL efficiency is high and CRI is excellent around 85. CFL produces a color temperature around 3K with its light being "soft white" around that color temp. Higher color temps are available.


Optical types

Non-cutoff
The non-cutoff fixtures usually include the globe-shaped lamps that are mounted on top of lampposts. These lamps distribute their light in all directions. A major problem is created by the light pollution and glare, as they shoot their light upwards into trees and towards the sky rather than down towards the ground. Non-cutoff fixtures are rarely found on roadways because they tend to blind the driver. NEMA farm & yard lights are common examples.


Semicutoff
This is the most popular streetlighting optic. The semicutoff fixtures usually refer to the cobraheads, but they can also apply to some lamppost-mounted fixtures that do not emit their light upwards. Most of the light can be emitted below 90 degrees, but as much as 5% of the light can also be emitted above 90 degrees. These fixtures do a very good job at spreading the light towards the ground, but some uplight is possible, though not as serious as non-cutoff fixtures. Often, the semicutoff fixtures are mounted on tall poles. Examples of semicutoff optics include the bowl-shaped diffuser on GE's M400s made prior to 1997, and the prismatic one shared by the Westinghouse OV-25, Crouse-Hinds L250 and OVM, and Cooper OVD. These fixtures are very commonly seen with both mercury vapor and HPS lamps (and sometimes metal halide as well).


Cutoff
These optics give more light control over semicutoffs. Less than 2.5% of the light can leave the fixture above 90 degrees. Cutoff fixtures have gained popularity in recent years, as they are available from manufacturers like GE and American Electric. The cutoff lights have a wider spread of light than full-cutoffs, and they generate less glare than semicutoffs. The cutoff lenses consist of a shallow curved glass (also called a sag lens) that is visible just below the lighting area on the fixture. As with the semicutoffs, these fixtures are very commonly seen with both mercury vapor and HPS lamps (and occasionally with metal halide as well).


Full-cutoff
These lights do not allow any of the light to escape the fixture above 90 degrees. Full-cutoffs distribute their light in a defined, tight pattern. In recent years, cutoff-type lights have gained popularity. To achieve the same result as cutoff or semicutoff fixtures, more full-cutoff fixtures would have to be installed, or they would have to be mounted higher. Although full-cutoff fixtures generally use HPS lamps, some metal halide and even a few mercury vapor ones have been known to exist.


Fixture type identification
Many streetlights are marked with stickers to aid workers in quickly identifying them. However the "code" isn't that hard and can be read by anyone for fun, say on a long road trip.

The system is as follows: The color of the sticker indicates the type of light, the number is one tenth of the power in watts. More power roughly corresponds to a brighter light.

There are three exceptions to this rule:

A "17" sticker adds a five to the power rating, and therefore, the light is rated at 175 watts.
If a sticker reads "X1," it describes a 1000-watt light.
If a sticker reads "3," it describes a 35-watt light.
Sticker colors:

Blue: Mercury vapor
Red: Metal halide
Yellow: Sodium vapor
Frequently seen power ratings:

"3" sticker--35 watts (HPS)
"5" sticker--50/55 watts
"7" sticker--70/75 watts
"9" sticker--90 watts (LPS)
"10" sticker--100 watts (MV)
"13" sticker--135 watts (LPS)
"15" sticker--150 watts
"17" sticker--175 watts (MH/MV)
"18" sticker--180 watts (LPS)
"20" sticker--200 watts (HPS/PSMH)
"25" sticker--250 watts (MV)
"31" sticker--310 watts (HPS)
"32" sticker--320 watts (PSMH)
"35" sticker--350 watts (PSMH)
"40" sticker--400 watts (MV)
"45" sticker--450 watts (PSMH)
"70" sticker--700 watts (MV)
"75" sticker--750 watts (PSMH/HPS)
"X1" sticker--1000/1500 watts (MV-H36 1000 W.)
"X2" sticker--2000 watts (MH)

Dear student, all the best. There is an answer to your question in what I have given you above..

Answer 2

i was looking at the streetlight and i thought... hmmm
it kinda looks like a tree
trees dont use any energy...too bad its not a plant
using gene splicing they CAN and (have-10/1?)
take the gene that glows in the dark and put it in a tree then the tree would be all lit up...

i heard (like ten years ago) they wanted to take the gene that makes thing glow and put it in christmas trees

im gonna guess 250 watts

it depents on what ghetto the streetlight is in

Answer 3

It varies but most are about 100 watts.

Answer 4

High Performance Tactical Flashlight - http://FlashLight.uzaev.com/?oKZX

Answer 5

maybe 500 watts