The lighting industry has standardized the lifetime of an LED fixture at L70 = minimum 50000 hours.The lifespan of LED bulbs does however depend on several key factors and LED luminaire lifetime tends to vary from 10,000 up to 50,000 hours.
Several factors influence the useful LED lifetime, or 'lumen maintenance' time. These variables include the operating cycle, the ambient temperature, material defects, electrical overstress etc.
LEDs are long-life light sources which generally do not suddenly fail, but gradually lose their brightness and performance over time. In other words, LEDs fade and don't actually blow. The rate at which an LED loses brightness depends on the operating conditions and on external factors such as temperature, relative humidity and changes in the thermal load. In some poorly designed LED lights, bad heat sinking can result in overheating, which in turn could cause the LED to completely burn out or increase the rate of decline in brightness. The LED driver that provides the power supply can also be unreliable and cause premature failure, it is often the driver that fails and the LED remains operational.
Because LEDs are as much as 90% more effective than incandescent light bulbs, they have a much longer lifespan. This is because they have no working parts that will burn out or break over time.
An average LED light is a very robust piece of kit. They are solid-state devices with no glass to break, nothing to wear out and they are not made from fragile glass that is likely to break. In turn, this means that they will last a whole lot longer than regular light bulbs.For the technically minded, the way they produce light is a crucial element of their longevity. Because they are made of substrate semiconductor materials and have two specific two doped regions, P – positive and N – negative. When current passes through the PN junction it causes electrons to jump to higher atomic energy states. When the electrons return to the ground state, light in the form of photons is emitted. This phenomenon is called electroluminescence and it consumes very little energy since very little heat is generated.