Standard incandescent bulbs used in street lights typically have a much shorter lifespan compared to other lighting technologies. On average, incandescent streetlight bulbs last between 1,000 and 2,000 hours. In terms of actual time in use, this means they may last 3 to 4 months when used continuously for around 10 to 12 hours each night.
Reasons for Short Lifespan:
- Heat Generation:
- Incandescent bulbs generate a significant amount of heat because they produce light by heating a tungsten filament to high temperatures. This heat causes wear and tear on the filament, leading to failure over time.
- Frequent Maintenance:
- Due to their short lifespan, streetlights using incandescent bulbs require frequent maintenance, which increases operational costs for cities or municipalities.
- Energy Inefficiency:
- Incandescent bulbs are inefficient, converting only about 10% of the electrical energy into visible light, with the remaining 90% lost as heat. This inefficiency makes them costly to operate, especially for street lighting where the lights are used for extended periods.
Replacement of Incandescent Bulbs:
Because of these limitations, incandescent bulbs are rarely used in modern street lighting. They have largely been replaced by more efficient and longer-lasting technologies such as:
- High-Pressure Sodium (HPS) Bulbs:
- These last 12,000 to 24,000 hours and are much more energy-efficient.
- Metal Halide Bulbs:
- These last around 15,000 to 20,000 hours and offer improved color rendering compared to HPS lamps.
- LEDs (Light Emitting Diodes):
- The most common replacement for street lighting today, LEDs can last 50,000 to 100,000 hours. They are far more energy-efficient and require significantly less maintenance compared to incandescent bulbs.
Summary:
Standard incandescent bulbs in streetlights last 1,000 to 2,000 hours, meaning they need to be replaced every 3 to 4 months under normal streetlight operating conditions. Due to their short lifespan and inefficiency, incandescent bulbs are rarely used in modern street lighting, having been replaced by longer-lasting and more efficient technologies like HPS, metal halide, and especially LEDs.