LED Lights

[justjun]

400W must be very light, consumption is also great.

[lesliemorris85]

This series arrangement works well until one of the bulbs burns out or is removed from the socket. Even LED strings of Christmas lights can fail if one bulb in the circuit burns out, especially if the string is wired in series, not parallel. It is always a good idea to keep spare bulbs available for last-minute emergencies.

[billvon]

Lots of companies are talking about equivalents with LEDs these days. Because there is really no standard that the industry observes I've seen some pretty unrealistic claims. As a rule of thumb for a street light, you can use about half the energy with LED versus HPS to get to the same minimum foot candles (light on the ground).

The best HPS lamps are more efficient than the best LED lamps. (150 vs 94 lumens per watt.) If you really want to go for efficiency, low pressure sodium can hit 200 lumens per watt. Which, of course, is why they are used for street lighting so often.

you can also mount the lights at a lower height so that you lose less light reaching the ground.

Not really true. You lose effectively zero light from the instrument to the ground unless you have very heavy fog or something.

High color temperature LEDs (cool white versus warm light) also offer a much whiter light than HPS, improving visibility with less light.

"Whiter" light actually reduce luminous efficiency, because your eye is most sensitive to greenish-yellow light (555nm). The extra light emitted by "white" (i.e. blackbody spectrum) lamps is less effective. Thus the ideal light source when it comes purely to sensitivity would be a monochromatic greenish-yellow source. This is why low pressure sodium lights are so effective; all their emission is around 590nm, and thus it's radiating very close to the color we can see most easily.

Of course there are other considerations like being able to see color (so you can tell a fire truck from a regular truck for example.)

[IlzeGreene]

400W HPS Equivalent

Lots of companies are talking about equivalents with LEDs these days. Because there is really no standard that the industry observes I've seen some pretty unrealistic claims. As a rule of thumb for a street light, you can use about half the energy with LED versus HPS to get to the same minimum foot candles (light on the ground). So strictly speaking you would need a 175W - 200W LED. This is huge load for solar.

Because good LEDs use optics that spread the light effectively, you can also mount the lights at a lower height so that you lose less light reaching the ground. You get less contrast, puddles of light, and that will improve visual acuity as well. If you have really good optics in the fixture.

High color temperature LEDs (cool white versus warm light) also offer a much whiter light than HPS, improving visibility with less light. Because of this, you might consider using a lower light level overall. For example: if your light currently is lit to a 1FC average with a minimum of .2FC, try lighting the whole lot at minimum .5FC average.

You don't have to figure it all out yourself. Reputable solar lighting companies can provide recommendations based on the Illuminating Engineers Society (IES) and help you to design an effective layout.
Parking Lot - LOS.jpg

[inetdog]

I am astonished to read of "overheating" problems with LED lights. On of the reasons why LEDs are so efficient as compared with incandescent lights are that they converts almost all the current to light, producing virtually no heat, as compared to incandescents where heat is a major by-product

If you have 25% efficiency from an LED (beyond what is currently available in most frequencies) that still means that you are dissipating three times as much power as you get out in the form of light. Also, there will be some amount of additional heat loss in the driver / current control circuitry.

25% is extremely high relative to incandescent (hovering around 2%) though!

[dazarooney]

Sounds good Russ.

[russ]

Just put LED lamps along the drive and was curious about power consumption.

The lamps are to provide light for walking and do that nicely. There are 9 lamps with 6 LED each and 1 with 12 LED.

Power consumption is 0.29 to 0.3 amps at 230 volts or about 69 watts for the 66 lamps.

I am quite happy with the arrangement.

[jiajaye]

The countries where summers season comes longer and hotter than winter Season.I think that Led Bulb dont work well there.That is why we dont find for LED bulbs in those countries

[dogsbody]

I am corrected. Most of the LEDS which I have used are about 125 milliwatt. I did not know that they had cranked them up to over 3 watts. In that case I can fully understand that they would need heatsinks, because diodes tend to change their properties when hot! (Like not work)

[john p]

Dogsbody. believe it,overheating IS a problem with LEDs. Due to their very small size its difficult to get the heat away from ones above 3w. That is why they have to be mounted on heatsinks. Failure to mount them on an adequate well ventilated heatsink will reduce their life dramatically.

I think grow lights are usually used for indoor gardening, plant propagation and food production, including indoor hydroponics and aquatic plants. Although most grow lights are used on an industrial level, some small-scale/domestic usage of these lamps has also been found. Mod note - forget the spam links

[dogsbody]

LED lighting issues

I am astonished to read of "overheating" problems with LED lights. On of the reasons why LEDs are so efficient as compared with incandescent lights are that they converts almost all the current to light, producing virtually no heat, as compared to incandescents where heat is a major by-product

[davetherave]

Led

I was wondering if anyone here knows of any companies out there that manufacturer LED street lighting that could substitute for a 400W HPS fixture at 30+ feet?

Try ROBUS they make heavy duty LED units, i have an LED wall washer, it makes the garden look like a spaceship!
they are heavy duty and extremely robust!

Kind regards

I know a little about LED light

I was wondering if anyone here knows of any companies out there that manufacturer LED street lighting that could substitute for a 400W HPS fixture at 30+ feet?

which country you'd like to know? Mod note - Forget the link

I know a little about LED light

Well their fly-by-night hackery saved me from your designs, and spending quite a bit of money. It's very telling that you are a government engineer and that explains everything I need to know about the value of your information. Welcome to my ignore list. It's been fun.

I know a little about LED light.Which country you'd like to know?