- Life Span of Solar Panels : Solar Panel last over 20 years.
- Life Span of LED : LED life is usually 50000 hours.
- Life Span of Battery: Battery life span varies depending on type of battery used. 1- 9 Years.
The efficiency of a solar light is reduced below 80% over a period of time which is considered the end of lifespan although the light does not stop working at this phase. Typically, an overall warranty of 2 to 8 years is promised by the solar light manufacturers. The performance and lifespan of solar lights depend on the quality of the parts used in the light system such as light source, battery, controller, solar panels and other components connecting all these together.
Light source: All the modern solar lights, especially solar street lights, use LED as their light source because LED lights are able to produce higher luminosity with lower energy consumption. Life of LED lights depend on their runtime and on an average, they can deliver 50,000 to 75,000 working hours and are less prone to failure with zero ultraviolet emissions.
Solar Panels: Solar panels are the most important and most expensive component of a solar lighting system. Monocrystalline or polycrystalline panels are used in solar lights. Solar panel life expectancy is anywhere around 25 years to 30 years and life of solar panel can be increased if they are well maintained.
Batteries: Lead acid batteries have a lifespan of 3 to 5 years but lithium ion or LiFePO4 batteries are widely used in solar lights due to their multiple benefits. Lithium ion battery can last for about 2 to 3 years and the typical estimated life of LiFePO4 batteries is approximately 5 to 6 years and the fact that they recharge faster can influence the total lifetime of the solar light system.
Solar Controller: PWM or MPPT controllers are used to protect the battery and regulate the voltage. Charge controllers typically have a lifespan of around 15 years and they decide when to switch on and switch off charging and lighting. Overcharging and undercharging of battery is also prevented with the help of controllers.
Solar light lifespan also depends on the exterior design of the unit. Solar lights are usually housed inside a casing made out of ABS plastic or metal alloy material. Since solar street lights and garden lights are used for outdoor lighting, waterproofing of the lighting units help the lights survive tough weather conditions. Solar street lights are often mounted on poles and thermally galvanized steel poles can last up to 40 years without rusting.
How long solar lights last is one of the most common questions asked by those who want to invest in solar lights. Solar light reliability and life also depend on how they are maintained. Although solar lights do not demand any maintenance as such routinely, occasional inspection and cleaning can help the performance of the lights and their overall life.