If USA and Canada converts all street and public lighting to LED or Compact Fluorescent..

[Vortex22]

Most of the traffic lights in my area are LED already (or at least that's what I think they are, looks just like LEDs)
Color is much brighter and easier to see than the old style lights.

 

[RU482]

CF street lights...ROFLCOPTER

anyone remember about 20 yrs ago, before all the street lights were orange (they used to be white in my hometown)

 

[Kelemvor]

How do halogen lights compare to normal fluorescent and CFL? We have 1 or 2 halogen lamps that are really bright but I have no idea how efficient they are...

THese are the kind that dim and the bulb is like a stick about 6" long or so.

 

[JS80]

Silly liberals

 

[Thorny]

Originally posted by: DrPizza

Originally posted by: Sphexi
There was an estimate that if all of the households in Canada switched to CFLs, it would save enough electricity to power a city of 100K people for a solid year. If all of North America did it, it could power a city of a million for a year. That's a decent amount of power saved, quite a few power plants that could be shut down.

No idea about street lighting, although there probably aren't nearly as many as there are lights in houses, I'm betting they draw more power, so perhaps the savings would be about the same? Different technology though, so I doubt it applies.

Saving the power demands of a city of a million = quite a few power plants?

While very gradually replacing the high pressure sodium lamps with piles of LED's (as the lamps failed) would save some energy, simply removing a perfectly good high pressure sodium lamp and replacing it with and LED would actually increase the power demands: LED's just don't grow on trees; it takes energy to make them. It'd be like tearing a house down and rebuilding it so you could squeeze in an extra half inch of insulation. (shot in the dark approximation)

Oh, also a consideration: in colder climates, particularly 2 story homes where the majority of lighting used is on the lower floor, the claim that energy is "saved" is exaggerated. The "wasted" energy of an incandescent bulb is heat - heat for your home. The only energy wasted (during the months you're heating your home) is the light that shines through your window to the outside. I probably should point out that in the big picture, this is true in homes that have electric heating. In homes with fossil fuel heating (coal, natural gas, propane, or oil), these fuels can be turned into heat at the home with far more efficiency than they can be converted to electricity at a power plant, and then sent to the home where they ultimately are changed back into heat.

i.e.
fossil fuel -> electricity -> home -> CFL bulb in a house with electric heat when it's cold outside: no energy is saved. The incandescent bulb's heat is not "wasted energy."

fossil fuel -> home -> heat;
small amount of fossil fuel -> electricity -> home -> CFL = saved energy. Not at the household level; the house uses just as much energy; but the inherent inefficiency of conversion of fossil fuels to electricity is where the savings occurs.

And, in my case,
3 tons of coal -> nice bright fire in the coal stove -> keeping my house at 75 to 80 degrees in the main living areas, cooler in the bedrooms for sleeping -> I can enjoy the nice warm glow of the fire and not turn on any lightbulbs in the room with the stove -> at a very small fraction of the cost to heat with any other fuel.

Wouldn't your argument about wasted heat be totally neutralized by the fact that most people run A/C during the summer months? I would think that removing that heat would cost just as much as it would save, especially given that my gas furnace can create it much more efficiently. I switched to CFL last year and this winter my energy consumption was still considerably lower. Yes my initial expense was high, but it's been less than 6 months and they have paid for themselves several times over.

On another note, for those of you that don't think that a city the size of a million people uses multiple power plants, you need to google it. My state of less than 13 million has 23 coal power plants and at least a dozen natural gas fired plants. TEXT shows the total number of generators in this country, granted there are several generators in a plant, but you get the idea.

 

[ghostman]

Well, they changed all the red and green bulbs for traffic lights to LEDs in NYC. How much did we save from that? I know nothing about what lights were used at traffic stops before...

 

[91TTZ]

Originally posted by: Whoozyerdaddy

Originally posted by: Heisenberg
I'm pretty sure that high pressure sodium lights are about the most efficient lights there are, even more than CFL and LED.

I didn't think there was anything commercially available that was more efficient than LED.

White LEDs aren't that efficient.

 

[Parasitic]

Disposal of old lamps might cause a problem.

 

[Rubycon]

Common white LED's found in many products today are not very efficient. The newest variety are getting there. At 100 lumens/watt the LED will make a formidable competitor to current discharge based lighting where the required color temperature and rendering indices are similar.

 

[Pepsi90919]

my region started moving to LEDs early on in traffic signals. now they have started moving back to brilliant incandescent lights, because the LEDs they were using were breaking and cracking.

 

[0roo0roo]

leds do fade.

as for lumens, the white ones aren't as efficient as those red/green ones used for traffic lights.

 

[theknight571]

I recently flew into Chicago at night.

I think that the City of Chicago could turn off every other street light, and no one but the power companies would notice.

(Note: I'm sure the same could be said for other big cities too)

 

[DrPizza]

Originally posted by: Thorny

Wouldn't your argument about wasted heat be totally neutralized by the fact that most people run A/C during the summer months? I would think that removing that heat would cost just as much as it would save, especially given that my gas furnace can create it much more efficiently. I switched to CFL last year and this winter my energy consumption was still considerably lower. Yes my initial expense was high, but it's been less than 6 months and they have paid for themselves several times over.

Yeah, I should have mentioned that. However, during the summer when A/C is in use, there are more daylight hours, hence lights aren't on for as much time.

 

[Thorny]

Originally posted by: DrPizza

Originally posted by: Thorny

Wouldn't your argument about wasted heat be totally neutralized by the fact that most people run A/C during the summer months? I would think that removing that heat would cost just as much as it would save, especially given that my gas furnace can create it much more efficiently. I switched to CFL last year and this winter my energy consumption was still considerably lower. Yes my initial expense was high, but it's been less than 6 months and they have paid for themselves several times over.

Yeah, I should have mentioned that. However, during the summer when A/C is in use, there are more daylight hours, hence lights aren't on for as much time.

Haha, you don't have kids do you? Some of my lights are on constantly even if they don't need to be 😛

 

[Mark R]

Typical efficiencies:

Tungsten incandescent (vacuum fill striplight) - 6 lm/W
Tungsten incandescent (standard bulb) - 12 lm/W
Tungsten incandescent (mains voltage halogen striplight) - 18 lm/W
Tungsten incandescent (low voltage halogen capsule) - 20 lm/W

Compact fluorescent (standard color quality, conventional start) - 50 lm/W
Compact fluorescent (standard color quality, electronic start) - 55 lm/W
Linear fluorescent (enhanced color quality) - 95 lm/W
Linear fluorescent (premium color quality) - 75 lm/W

Metal halide (Daylight color) - 85 lm/W
High pressure sodium - 140 lm/W
Low pressure sodium - 165 lm/W

LED (white, current technology) - 60 lm/W
LED (white, prototype) - 90-100 lm/W
LED (green, current technology) - 50 lm/W (but avoids need to use light blocking colored filters)

 

[MrPickins]

All the street lights I've seen for the past 10 years or so have been low pressure sodium:

Low pressure / LPS / SOX

LPS Lamps (Low Pressure Sodium), also known as SOX Lamps (Sodium OXide), consist of an outer vacuum envelope of glass coated with an infrared reflecting layer of indium tin oxide, a semiconductor material that allows the visible light wavelengths out and keeps the infrared (heat) back. It has an inner borosilicate 2 ply glass U shaped tube containing sodium metal and a small amount of neon and argon gas Penning mixture to start the gas discharge, so when the lamp is turned on it emits a dim red/pink light to warm the sodium metal and within a few minutes it turns into the common bright orange/yellow color as the sodium metal vaporizes. These lamps produce a virtually monochromatic light in the 590 nm wavelength. As a result, objects have no color rendering under a LPS light and are seen only by their reflection of the 590 nm light (orange).

LPS lamps are the most efficient electrically powered light source when measured for photopic lighting conditions. ? up to 200 lm/W[1]. As a result they are widely used for outdoor lighting such as street lights and security lighting where color rendition is viewed by many to be less important. LPS lamps are available with power ratings from 10 W up to 180 W, however length increases greatly with wattage creating problems for designers.

LPS lamps are more closely related to fluorescent than High Intensity Discharge lamps, since they have a low?pressure, low?intensity discharge source and a linear lamp shape. Also like fluorecents they do not exhibit a bright arc as do other HID lamps, rather they emit a softer luminous glow, resulting in less glare.

Another unique property of LPS lamps is that, unlike other lamp types, they do not decline in lumen output with age. As an example, Mercury Vapor HID lamps become very dull towards the end of their lives, to the point of being ineffective, whilst still drawing their full rated load of electricity. LPS lamps, however, do increase energy usage towards their end of life, which is usually rated around 18,000 hours for modern lamps.

http://en.wikipedia.org/wiki/Sodium_vapor_lamp

Much more efficient than LED's or CF.

 

[biggestmuff]

Originally posted by: Sphexi
There was an estimate that if all of the households in Canada switched to CFLs, it would save enough electricity to power a city of 100K people for a solid year. If all of North America did it, it could power a city of a million for a year. That's a decent amount of power saved, quite a few power plants that could be shut down.

No idea about street lighting, although there probably aren't nearly as many as there are lights in houses, I'm betting they draw more power, so perhaps the savings would be about the same? Different technology though, so I doubt it applies.

You wouldn't be saving electricity. You'd be generating and using less electricity.

 

[Rubycon]

Originally posted by: Pepsi90919
my region started moving to LEDs early on in traffic signals. now they have started moving back to brilliant incandescent lights, because the LEDs they were using were breaking and cracking.

Sounds like a rush using designs not tested to withstand the rigors of the environment. LED's are semiconductor devices and are quite sensitive to spikes and over temperature if the proper safeguards and engineering guidelines are not strictly adhered to. There have been reports of traffic signals with many LED's out in the cluster. Future designs will only improve obviously - these are the growing pains of using relatively new technology adapted in rather harsh environments.

Originally posted by: Mark R
Typical efficiencies:

Tungsten incandescent (vacuum fill striplight) - 6 lm/W
Tungsten incandescent (standard bulb) - 12 lm/W
Tungsten incandescent (mains voltage halogen striplight) - 18 lm/W
Tungsten incandescent (low voltage halogen capsule) - 20 lm/W

Compact fluorescent (standard color quality, conventional start) - 50 lm/W
Compact fluorescent (standard color quality, electronic start) - 55 lm/W
Linear fluorescent (enhanced color quality) - 95 lm/W
Linear fluorescent (premium color quality) - 75 lm/W

Metal halide (Daylight color) - 85 lm/W
High pressure sodium - 140 lm/W
Low pressure sodium - 165 lm/W

LED (white, current technology) - 60 lm/W
LED (white, prototype) - 90-100 lm/W
LED (green, current technology) - 50 lm/W (but avoids need to use light blocking colored filters)

You left out mercury vapor and sulfur lamps! 😉

Speaking of sulfur lighting it's a cool way (not in a literal sense by any means) to produce white light. If LED's weren't on the horizon as formidable contenders for future high intensity replacements, I'm sure we'd see some interesting developments in the microwave generator sector.

Originally posted by: MrPickins
All the street lights I've seen for the past 10 years or so have been low pressure sodium...


Much more efficient than LED's or CF.

Most streetlights are HPS not LPS. LPS can be easily distinguished by its deep yellow-orange glow which looks just like sodium burning on water. They are can be found in tunnels and parking garages. The biggest complaint from people is they have a hard time finding their car because of the zero CRI of these lamps! HPS have a much whiter output with a golden glow and measurable CRI. Potheads use them to raise their goods too. 😉

Currently LPS have the highest efficacy but LED technology will surpass it - and have excellent CRI as well. 500 l/w is not out of the question with LED's! :shocked: They will become a serious candidate for stage lighting. 😀

 

[Mark R]

Originally posted by: MS Dawn
Most streetlights are HPS not LPS.

Round here, it's uncommon to see HPS street lights - the vast majority are LPS. However, there are plans to replace them, in time. It's quite common for new projects to use HPS. In fact, in my town, they have a rather progressive policy and both LPS (and the few HPS) streetlights are now being phased out, and replaced with metal halide.

500 l/w is not out of the question with LED's! :shocked: They will become a serious candidate for stage lighting. 😀

I was under the impression that reasonably white light only had about 400 lm/W in it - so achieving an efficacy of 500 lm/W is likely to be a challenge for any technology 🙂

 

[Rubycon]

Yes Metal Halide will have the best CRI of the HID families. Imagine if they used LPS to illuminate car lots and stadiums. :laugh:

In Europe the LPS is much more widespread. As a matter of fact while the US was still predominately lighting the highways and streets with Hg vapor, Germany was on the SOX bandwagon. :Q

Besides length, the other way to tell is at startup. LPS will be neon red (as the starter gas is neon) and HPS will be purple to blue - some actually look like uncoated Hg lamps when starting up - again due to the starting agents.

500 l/w seems to be the holy grail - no doubt they'll reach it using heaven knows what for doping. Goggles will actually be required when messing with discrete emitters. :shocked:

 

[totalcommand]

Originally posted by: Thorny

Originally posted by: DrPizza

Originally posted by: Sphexi
There was an estimate that if all of the households in Canada switched to CFLs, it would save enough electricity to power a city of 100K people for a solid year. If all of North America did it, it could power a city of a million for a year. That's a decent amount of power saved, quite a few power plants that could be shut down.

No idea about street lighting, although there probably aren't nearly as many as there are lights in houses, I'm betting they draw more power, so perhaps the savings would be about the same? Different technology though, so I doubt it applies.

Saving the power demands of a city of a million = quite a few power plants?

While very gradually replacing the high pressure sodium lamps with piles of LED's (as the lamps failed) would save some energy, simply removing a perfectly good high pressure sodium lamp and replacing it with and LED would actually increase the power demands: LED's just don't grow on trees; it takes energy to make them. It'd be like tearing a house down and rebuilding it so you could squeeze in an extra half inch of insulation. (shot in the dark approximation)

Oh, also a consideration: in colder climates, particularly 2 story homes where the majority of lighting used is on the lower floor, the claim that energy is "saved" is exaggerated. The "wasted" energy of an incandescent bulb is heat - heat for your home. The only energy wasted (during the months you're heating your home) is the light that shines through your window to the outside. I probably should point out that in the big picture, this is true in homes that have electric heating. In homes with fossil fuel heating (coal, natural gas, propane, or oil), these fuels can be turned into heat at the home with far more efficiency than they can be converted to electricity at a power plant, and then sent to the home where they ultimately are changed back into heat.

i.e.
fossil fuel -> electricity -> home -> CFL bulb in a house with electric heat when it's cold outside: no energy is saved. The incandescent bulb's heat is not "wasted energy."

fossil fuel -> home -> heat;
small amount of fossil fuel -> electricity -> home -> CFL = saved energy. Not at the household level; the house uses just as much energy; but the inherent inefficiency of conversion of fossil fuels to electricity is where the savings occurs.

And, in my case,
3 tons of coal -> nice bright fire in the coal stove -> keeping my house at 75 to 80 degrees in the main living areas, cooler in the bedrooms for sleeping -> I can enjoy the nice warm glow of the fire and not turn on any lightbulbs in the room with the stove -> at a very small fraction of the cost to heat with any other fuel.

Wouldn't your argument about wasted heat be totally neutralized by the fact that most people run A/C during the summer months? I would think that removing that heat would cost just as much as it would save, especially given that my gas furnace can create it much more efficiently. I switched to CFL last year and this winter my energy consumption was still considerably lower. Yes my initial expense was high, but it's been less than 6 months and they have paid for themselves several times over.

Actually, it would be more than neutralized. It takes SIGNIFICANTLY more energy to cool a place than to heat it (simple thermo). So the wasted heat by the incandescent would require a larger amount of energy for the AC to cool down.

Further, some of the energy the incandescent uses is converted to visible light. It is not the best heat generating source, which is why we have electric furnaces. So the tradition light bulb is not a direct 1:1 substitute for heating in our homes in the winter. This is probably why you saved money during the winter.

 

[MrPickins]

Originally posted by: MS Dawn

Most streetlights are HPS not LPS. LPS can be easily distinguished by its deep yellow-orange glow which looks just like sodium burning on water. They are can be found in tunnels and parking garages. The biggest complaint from people is they have a hard time finding their car because of the zero CRI of these lamps! HPS have a much whiter output with a golden glow and measurable CRI. Potheads use them to raise their goods too. 😉

Currently LPS have the highest efficacy but LED technology will surpass it - and have excellent CRI as well. 500 l/w is not out of the question with LED's! :shocked: They will become a serious candidate for stage lighting. 😀

Believe me I know the difference between SOX and SON lamps.

Again, for the past 10 years I have only seen SOX streetlights, there is no mistaking that monochrome glow.

Maybe my area is more progressive than the rest of the nation, but considering I live in TX, I doubt it. 😉

 

[FoBoT]

help?

 

[Jeff7]

Originally posted by: totalcommand
Actually, it would be more than neutralized. It takes SIGNIFICANTLY more energy to cool a place than to heat it (simple thermo). So the wasted heat by the incandescent would require a larger amount of energy for the AC to cool down.

Further, some of the energy the incandescent uses is converted to visible light. It is not the best heat generating source, which is why we have electric furnaces. So the tradition light bulb is not a direct 1:1 substitute for heating in our homes in the winter. This is probably why you saved money during the winter.

Um, no? When we used electric heat at home, the winter electric bills would sometimes be $400 for just one month, and that was for heating upstairs and maybe one room in the basement. It was less than half of that in the summer for air conditioning the entire house. It's not a big house, mind you, maybe 1000 sq ft per floor. It's a one story house with a basement.

In winter, it might be 0 degrees outside, but you might want it 70F inside. 70 degree difference.
In summer, it might be 100F outside, but you'd still want it 70F inside. 30 degree difference.
Maybe if it was 140F outside, then you'd be looking at closer numbers, simply because the temperature differential would then be the same.

Lightbulbs do create a lot of heat for the energy they consume. A CFL produces the same amount of light as a 60W incandescent for the cost of maybe 15W, and even the CFL will get too hot to touch. That means that at least 45W of the incandescent's power consumption is being turned into heat.

But let's say you'd want to match the output of a 1500W space heater. Right there you'd need around 30 60W lightbulbs, maybe less depending on actual heat output per bulb, not just my estimate. A 1500W space heater isn't really good for heating anything other than a fairly small room.
My opinion of light bulb contribution to household temperatures: negligible.

 

[Rubycon]

LED's are now at 75 l/w!

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