Are you wondering; How much does a street light cost? Or even, how much does it cost to install a street light? The following article will explain all of the true LED street light costs and answer both of those questions and show you the true advantages of LED street lights.
The cost of any LED lighting system has the following components and considerations:
1. Material cost of bulb, poles and electrical wires and labor cost of installing the light
The cost of installing one street light pole is generally around $4000. It depends on the height of the pole, the rated power and efficiency of the light, type of foundation needed and length of wiring from the nearest source of electricity. When the nearest source of electricity is too far away as in rural communities it may be wise to install solar powered street lights instead of laying down miles of wire to energize the light. However, solar power solutions are considerably more expensive than a grid lit street light.
2. Cost of energy consumed by the bulb
A 100W Retrofit Kit designed to replace the metal halide bulb inside an existing street light fixture consumes 100 watts and produces 15,550 lumens of high quality light. By comparison, the 209,000 street lights of Los Angeles use 197,000,000 kWh of electricity every year at the rate of 250 watts per hour. Cost savings in electricity costs by adapting the LED alternative is what is propelling Los Angeles and many other cities towards LED lighting systems.
Added to this is the fact that Low Pressure Sodium (LPS) lights that produce the most light per watt have a Color Rendering Index (CRI) of ‘zero’. For good visibility they need to be combined with incandescent bulbs. The 5% efficiency rating of incandescent bulbs pulls down the efficiency of LPS lights as well. LPS lights are thus not suited for general purpose street lighting. Slightly better than that are High Pressure Sodium Bulbs, but those lights are typically 2700K and have a CRI between 20-40. Their light quality is terrible, and they must produce a lot of lumens to make up for the poor quality of light. Metal Halide, a brighter white light, tends to be a higher quality light source, with some bulbs approaching the CRI of LED, however, the majority of those bulbs are around 60 CRI. LED CRI typically starts at or above 70 on the scale of 0 to 100.
The function of providing security is compromised with lights with low CRI. Police forces dislike low CRI lights because they make it impossible to tell colors apart. Yellow is the only color that is reflected. If an object does not reflect yellow light it appears black. Disruptions in the road are also difficult to visualize because the road and the dents all appear yellow! Poor contrast and color rendering necessitate that more powerful lights are needed to achieve the objectives of street lighting. Powerful lights in turn lead to glare which again compromises the ability of the human eye to see objects clearly. Indeed in areas where security is important mercury and metal halide lamps are preferred despite their inefficiencies and are rapidly being replaced by LED lights that cost a fraction to operate and maintain.
A comparison of good CRI lights shows that lights offered by MyLEDLightingGuide outperform the others by a wide margin on all parameters, thus making any street light cost more plausible to put forward for more consideration to make the switch to a LED street lighting system.
|LED Light||High Pressure Sodium||Mercury Vapor||Incandescent|
|Actual light availability (Lumens)||15,500||14000||14000||2800|
|Hours of operation per night||10||10||10||10|
|Cost of electricity ($/kWh)||0.10||0.10||0.10||0.10|
|Annual Consumption (kWh)||383||913||1460||1460|
|Annual electricity charges ($)||38.3||91||146||146|
|Cost per 100 Lumens||0.24||0.65||1.04||5.21|
|Average Life Span (years)||20+ *||5||4||3|
*rated L70 of 100,000 hrs, 3650 hours per year average use
Cost of replacing burnt out bulbs and disposal of bulbs
We may not realize it but the cost of monitoring and replacing bulbs can be very high for street lights. Los Angeles spends 42 million dollars for monitoring and maintaining 209,000 street lights. This works out to more than $200 per street light per year.
The reason for the high cost is that street lights are placed at a height that necessitates the use of a cherry picker to carry workers to the light and a truck to carry the man-lift. Christian B. Luginbuhl of the U.S. Naval Observatory Flagstaff Station carried out a detailed comparison of different outdoor light options and concluded that Low Pressure Sodium lamps last 6000 hours less than HPS lamps leading to higher maintenance costs. Besides ‘zero’ color rendering ability, this is an important reason why Low Pressure Sodium lights have not become widely accepted. HPS and Metal Halide bulbs last, on average, 12,000 to 15,000 hours. Even worse, their L50 (lumen degradation to 50% of initial output) occurs at half life.
Replacing One Bulb Calculation:
- Cost of replacement bulb +
- Salary of 2 people +
- Rental of Man Lift +
- Truck Rental or Truck Costs
= $800 (Assuming cost of one bulb and ballast to be around $150).
*All cost calculations are based on the data of US cities and reports by residents who have to pay directly for the replacement of street light bulbs.
Cities have found that funds available for maintenance have been frozen while expectations of service quality remain unchanged. Technology offers the only way out of the dilemma. Remote monitoring systems pare the cost of physical verification of lights while LED technology has extended the life of each light to 12 to 15 years from the current 5 years. The city of Ann Arbor had estimated that the savings in maintenance costs are higher than the savings in energy.
How much Money will you save converting your lighting over to LED?
So you have a Metal Halide (or even High Pressure Sodium) light, and you want to convert to LED. You’ve done your research, you’ve been inundated with marketing materials that tell you what is the most important thing to consider (coincidentally it probably is something they think is important). And how much money will you save per light after you convert to LED?
Lets do 2 comparisons, converting 400W Metal Halide and 1000W Metal Halide over to LED. We will compare it to lights that will produce high quality light that will give your outdoor parking lot a safe, highly lit environment. We will use 12 hours a day operating time, essentially these lights are only turned on at night.
For purpose of this example, we will discuss 2 of our more popular
Scenario 1 – Replace 400 Watt Metal Halide
Each 400 Watt Metal Halide actually consumes around 455 Watts, including the power the ballast consumes. We will use a 120 Watt LED Outdoor Shoebox Fixture producing 16,800 lumens, backed with a 10 year warranty.
Using our Energy Savings Calculator per fixture per year over 400 watt Metal Halide:
- .10 kw/h, savings are $148.92 per fixture per year
- .12 kw/h, savings are $178.70 per fixture per year
- .14 kw/h, savings are $208.49 per fixture per year
- .16 kw/h, savings are $238.27 per fixture per year
- .18 kw/h, savings are $268.06 per fixture per year
- .20 kw/h, savings are $297.84 per fixture per year
Scenario 2 – Replace 1000 Watt Metal Halide
Each 1000 Watt Metal Halide
actually consumes around 1150 Watts, including the power the ballast consumes.
We will use a 300 Watt LED Outdoor Shoebox Fixture producing 45,900 lumens, backed
with a 10 year warranty.
Using our Energy Savings Calculator per fixture per year over 1000 watt Metal Halide:
- .10 kw/h, savings are $372.30 per fixture per year
- .12 kw/h, savings are $446.76 per fixture per year
- .14 kw/h, savings are $521.22 per fixture per year
- .16 kw/h, savings are $595.68 per fixture per year
- .18 kw/h, savings are $670.14 per fixture per year
- .20 kw/h, savings are $744.60 per fixture per year
What about Payback?
So how do you calculate payback when you are converting your Metal Halide or HPS lights over to LED Fixtures? Here is some guidance on how you can make that calculation
1. Add up all your costs: Cost of LED Fixture + Cost of Installation + Cost of Disposal
2. Subtract the cost of utility rebates to get your total cost
3. Divide this total cost by your per year savings from the tables above.