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Energy Efficient LED Lighting for Parking Lots


A Metal-Halide lamp is an electrical lamp that produces light by an electric arc through a gaseous mixture of vaporized mercury and Metal Halides (compounds of metals with bromine or iodine). It is a type of high-intensity discharge (HID) gas discharge lamp. The most common metal halide compound used is sodium iodide.

Traditionally, high-intensity discharge (HID) fixtures have been the go-to for illuminating outside parking areas. These high-power lighting sources provide basic, low-grade light, are expensive to maintain, consume a large amount of power, and are unpleasant to the eye. LED parking lot lights require no maintenance, consume significantly less power, and provide better light quality, which makes them a great alternative to HID fixtures.

1000w Metal Halide users have often depended on the higher light levels for safety and security of shopping centers and parking lot lighting. As well these fixtures have been key in promoting and displaying product at automobile dealerships for years. Unfortunately these high wattage fixtures consume a ton of electricity often resulting in demand charges from utility companies. However with advancement in LED Lighting, the 1000w Metal Halide fixture is now a thing of the past.

What Does It take To Replace 1000w Metal Halide?

First we must understand that arming ones self with the facts is the most important key to replacing 1000w Metal Halide. All too often, Auto Dealerships and Business Owners have been left disappointed in their investment with LED Lighting simply because they didn’t know what they were buying.

1000W Metal Halide Fixtures can produce upwards of 100,000 lumens when a new bulb and ballast are installed. Though this may seem like a lot of light, it really isn’t nearly as much as it sounds. This measure is at the arc tube in the center of the 1000w lamp. Once the light is emitted, it bounces around in the fixture before it is reflected on to the ground. This causes a drastic drop in lumens by the time the light travels from the fixture to the illuminated surface. Secondly, as the Metal Halide lamp ages, it is typical for the lamp itself to depreciate by as much as 35 percent within the first six to nine months from the date of installation. The end result is a lumen discharge somewhere in the vicinity of 43,000 lumens.

Now that we have a true lumen value of 43,000 lumens from a 1000w Metal Halide fixture, we now have to accommodate for and deduce a reasonable amount of light loss from stray emissions. This is light that travels semi horizontally, and sometime vertically away from the illuminated surface and into the sky. This stray light sometimes referred to as “Sky-Glow” or “Light Trespass” is responsible for another loss averaging 40 percent of the emitted light. This light that never makes it to the actual surfaces to be illuminated is wasted light, and wasted kilowatts of electricity.

Now that we have deduced from the initial 100,000 lumens emitted by the 1000w lamp, to the end result of 26,000 delivered lumens to the illuminated surface, we can now measure the required lumens necessary to replace 1000w Metal Halide with an LED Light Fixture ± 10 percent. This means that to accurately replace your 1000w Metal Halide, the LED fixture must produce at least 23,400 delivered lumens, up to 28,600 at a high to be considered an “Equal”.

Benefits of Replacing 1000w Metal Halide With LED

Obviously we all know by now that LED Lighting saves money because it is a lower wattage than Metal Halide and traditional light sources and no longer requires a maintenance expense with replacement bulbs and ballasts. However here are some other benefits you may not know:

Increased Uniformity:
Because Metal Halide delivers an intense amount of light from a single pinpoint source, this creates hot spots under the fixture. When using LED Lighting with multiple emitters and focus controlled optics, hot spots are eliminated and a more consistent coverage of light on the ground is created. This reduces the darker areas between poles and smooths out the lighting across a property. This is known as Uniformity. There are several measures such as 20:1, 15:1 and 10:1 enhanced security. This is a measure of how smooth the transition is of light control from one pole to another. The lower the uniformity ratio, the better quality of light across a property.

Increased See-Ability:
Though this is a new word you won’t find in the Dictionary, it has become an often used word in the lighting industry to surmise the effect of Scotopic Effect. This is different than Photopic Effect. The basic difference here is how the human eye perceives light. A lumen or foot candle meter reads photopic lumens. Yet the human eye through rods and cones (red, green, blue receptors in the retina), perceive on a scotopic level. Natural Bright Light, constricts the pupils which are dialated at night, and with the color temperature of LED white light, and constricted pupils, the light emitted from an LED Fixture is perceived at a higher level than traditional Metal Halide. This makes illuminated surfaces appear brighter under LED Light at night. Therefore 26,000 lumens from an LED can appear more like 43,000 lumens from a Metal Halide.

Here is a list of Metal Halide’s we typically see:

  • 175 Watt Metal Halide Fixture = 205 Actual Watts
  • 250 Watt Metal Halide Fixture =290 Actual Watts
  • 400 Watt Metal Halide Fixture = 458 Actual Watts
  • 1000 Watt Metal Halide Fixture =1,081 Actual Watts

Color, Brightness, and Lumen Depreciation

Light from an Metal Halide can range from natural white color to orange and green depending on the type of bulb. Metal Halides will begin to emit light with a pink hue from extended use. This indicates that the bulb needs to be replaced. It’s also possible to see green or blue light from Metal Halides, which can happen when the capacitor is failing. LED parking lot fixtures maintain the same natural white or cool white color throughout their entire life span.

Energy Costs

With energy consumption that is less than half of what Metal Halides consume, LED parking lot lights save a great deal of money in annual electric costs.  ENERGI PROS™ offers a 200 watt LED parking lot light that is a direct replacement for 1000 watt Metal-Halide.  That’s 800 watts less for the same amount of light!

Using the average price of electricity per kilowatt-hour (kWh) of 12 cents.  To figure out the monthly cost of running 25 LED parking lot lights for 11 hours per day, use this formula: (combined wattage x monthly hours of use)/1,000 x price per kWh.  For 25 LED lights, (5,000 x 330)/1,000 x .12) the total would be $198.00 per month or $2,376 per year.

When the same formula is used for 1000-watt Metal Halides, the monthly cost is $990, and yearly cost would be $11,880. So, in this situation, switching to LED fixtures would save approximately $9,504 per year.  When coupled with the savings on maintenance, LED fixtures can save $12,925 per year.  At that rate, the investment cost of 25 LED parking lot lights could be recouped in less than nine months.

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