LED Street Light FAQ

Reno public LED lighting

The stars shine over Renton, Washington, where a switch to LED lighting reduced energy costs and nighttime light pollution.

Ameresco, an energy effficiency company, has prepared this LED street light FAQ to help commercial and municipal energy consumers understand the significant benefits of upgrading existing outdoor and roadway lighting to LED technology. With the highest level of energy efficiency available today and significantly lower maintenance costs, LED street lights and LED traffic lights should be top of mind for all wide area lighting needs.

What are LED lights? 
LED stands for Light Emitting Diode, a semiconductor, very similar to a computer chip, that turns energy into light. Unlike sodium vapor lamps or fluorescent lamps, an LED does not burn a fuel to generate light. Instead, it uses a small amount of energy to excite phosphors that create light. 

Why do LED street lights use less energy? 
The difference in energy use between LED street lights and other types of roadway lighting lies in how they create light. In sodium vapor lights, a filament burns gas to create light. Most of the energy for these lights is lost to heat, which makes them expensive to operate. Fluorescent lights are more efficient, but they also rely on an electrical charge that creates more heat than light.

LED lights are up to 95% efficient; in other words, they lose only 5% of the energy they consume to heat, with the rest generating light. Switching from sodium vapor street lighting to LED street lighting can reduce energy use by up to 60%. Carbon emissions are also lowered, because less energy needs to be generated to keep the lights on. For commercial and municipal energy consumers, this can add up to significant annual savings.

"The increased efficiency and decreased long-term operating cost that LED technology provides allows the City the ability to improve service while keeping costs in line. With the help of Ameresco, we’re putting together a project that will pay dividends well into the future."

--Yakima Public Affairs Director Randy Beehler

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Why are LED street lights less expensive to maintain? 
Because LED lights don’t burn fuel, their lifespan is limited only by the quality of the LEDs themselves and the lifespan of the phosphors that generate the light. All phosphors fade over time, but LED lights typically have a lifespan of 15 years in normal daily use.

Sodium vapor and mercury vapor streetlights, by comparison, last only 5 to 6 years, on average. Filaments burn out eventually in sodium vapor street lights, and both incandescent and fluorescent bulbs will fail if damaged.

In areas with variable climates that shorten the life of fluorescent and incandescent bulbs, solid-state LED technology provides even fewer maintenance worries. LED lighting is also completely free of mercury and other polluting substances, making it a more environmentally friendly choice.

Do LED street light bulbs cost more?  
The up-front cost of an LED bulb is higher; however, when you consider the significant energy savings and reduced lifetime maintenance costs, LED street lights are the least expensive option available today. Their longer lives and higher durability mean that LED bulbs are more reliable, making them a superior choice for areas where lighting is needed for public safety.

Depending on the number of street lights or outdoor lights replaced, LED bulbs can pay for themselves in one to three years through lower energy and maintenance costs.

How does LED light compare to other types of light? 
Good LED bulbs deliver truer white light for improved visibility and color rendering. Unlike sodium vapor lamps, they won’t turn everything orange. Colors look more natural under LED lights, making them an excellent choice for parks and signage.

LED lights can also be “aimed” through the use of internal optics, which minimizes bleed into nearby homes and puts light into the places where it is most needed.

Will LED work with existing light fixtures? 
LED bulbs have been developed to fit the most commonly used roadway, outdoor and street light fixtures. If mercury or sodium vapor bulbs are currently in use, there’s an LED alternative available.

For fluorescent tube lighting, new fixtures are generally necessary. Like the LED bulbs themselves, the costs for these new fixtures can be spread out over time, and in some cases there are no up-front costs for a retrofit.

Why choose Ameresco?
Ameresco is a nationwide energy efficiency company with extensive experience in municipal and commercial energy efficiency retrofits. Ameresco is not a manufacturer or distributor, so our partners can choose from the products that best meet their needs and budget, including LED street lights from General Electric, Cree, Osram and other leading manufacturers.

As a full energy services company, Ameresco also has expertise in finding and securing energy efficiency rebates, incentive programs and financing options, including energy savings performance contracts. In many cases, municipal and commercial organizations can upgrade to LED lighting with no up-front costs, using energy savings to pay for the new lights over time.

Demand response cityscape


Electrical savings totaled more than $840,000 annually and maintenance savings totaled more than $87,000 annually after the City of Henderson, Nevada, chose to replace existing incandescent lighting with durable, energy efficient LED street lights. The project also helped to reduce carbon emissions by lowering the amount of electricity needed to power the city's outdoor lighting.

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Let Ameresco's team of LED lighting experts help you discover the benefits of upgrading existing incandescent or fluorescent street lights to LED.