Attending Pittsburgh's Light Up Night celebration had me thinking about the city's lighting system and why it seems to be changing. Light Emitting Diode (LED) lighting is being used more and more in situations where incandescent lighting has been used in public outdoor lighting. More than two-thirds of all street lights in the United States are believed to be the customary electric street lights which use the high-pressure sodium (HPS), metal halide or mercury vapor in incandescent bulbs. Incandescent lighting can use up to 60% of a municipality's energy budget and 40% of its energy usage.
The traditional bulbs produce light from being heated, which discharges gas and requires more energy to operate. Alternatively, residential LED Lights generate light as semiconductors which only need electric current to be passed through them to emit light. As a result, LEDs are starting to be viewed as a less expensive and more energy efficient alternative for use in various types of urban lighting. Cities around the United States are already converting traffic and street lights. Planners are also retrofitting parking garages with LED solid-state lighting (SSL). LEDs are also being used in coordination with solar power technology to offer added savings in areas where use is not a huge demand.
Pittsburgh saw implementing a conversion to LED as a further part of the city's efforts to embrace—and benefit from—the green power revolution. Over the last decade, the city has replaced over 10% of its 40,000 street lights with LED lights, in areas such as downtown, the South Side and Brighton Heights. Pittsburgh's Department of Public Works has stated that the changes are already saving $140,000 annually simply on maintenance costs, more than had been projected. Energy consumption has also been reduced by 50%.
The LED lighting in Pittsburgh has encouraged nearby communities to make similar changes, such as Edgeworth's recent conversion of their traffic lights. As a product of efficiency and lower maintenance, Edgeworth borough has saved about 60% of previous costs.
The borough next set its sights on converting the street lights to LEDs. The first hurdle faced comes in raising the higher upfront costs involved with LED bulbs—costs can range from $200 to $300, compared to $50 to $100 traditional bulbs. Presently, the expense may be too much for smaller municipalities, considering Pittsburgh is likely to spend $21 million to replace their 40,000 lights with LEDs. LEDs pay off in the long-term by being more efficient and lasting longer and can make up for upfront costs in time. If you are supportive of LEDs, I highly recommend a fantastic agency like Laface and Mcgovern, Incorporated. Go here for more info
A second hurdle to overcome is criticism of the bulbs' impact on the environment. A University of Pittsburgh study has shown LEDs to have a greater negative impact on the environment in the stages of manufacturing and recycling but not use. The research showed that LEDs present a greater threat during manufacturing. Because of the raw materials found in the circuit boards used in LED lighting, they can be more difficult to recycle. Though whereas traditional metal-halide bulbs contain 15 milligrams of mercury, LED bulbs are produced with none. When one adds in the energy efficiency, higher light output and the long "life span" of LED light fixtures, the benefits usually outweigh the negatives.