Do solar LED lights need direct sunlight?

If you are a solar power enthusiast, you already know that solar LED lights give out their best performance if they receive direct sunlight during the day.  It is always encouraged to install the lights at a location where the solar panels can receive as much sunlight as possible throughout the day in order to perform to their fullest potential at night.  And this is possible in India as we receive many sunny days for most part of the year; however, we also get a lot of rainy and cloudy days.

How do solar LED lights work?

The concept behind solar lights is simple and the working principle is called photovoltaic effect.  Solar panels harvest solar energy using solar cells and convert this into usable direct electrical current.  Solar batteries store this energy and light up the LED.  The photoreceptors sense the presence and absence of sunlight and help the solar lights to work automatically from dusk to dawn.

Do solar LED lights work only with direct sunlight?

The charging of solar lights is affected during non-sunny days when sunlight cannot penetrate fully through the clouds.  But this does not mean they entirely block the sunlight and cloudy days are not entirely dark.  The diffuse light colliding with clouds and bouncing off the ground, though less intense than direct light, is sufficient to keep the photovoltaic system running.  Therefore, solar panels continue to work even when they receive sunlight partially blocked by clouds and generate electricity with indirect sunlight.  However, the degree of solar radiation will depend on the cloud density and the power generation efficiency will change accordingly.

Modern solar LED lights

The new generation solar LED lights use lithium-ion (3.7v) or lithium iron phosphate (3.2v) batteries, which charge faster and use less voltage.  The panels are not required to generate a lot of current to charge these batteries.  Hence, even if the panels do not have access to direct sunlight, the charging will continue at a slower rate.

The efficiency of a solar LED light depends on the type of solar panel and charge controller.  MPPT controllers produce almost twice energy than PWM controllers and monocrystalline panels perform better in cold climates.  High luminous LED offers better illumination although there will be a drop in the longevity during overcast conditions depending on the charge.

The charge capacity of solar LEDs may get weaker during non-sunny days; however, modern solar lights are designed to maintain charge in the batteries for longer hours.  Solar lights with motion sensors and timer-based energy-saving options conserve energy and help the lights to continue shining for two to three days before having to recharge.

What can you do to ensure better performance from your solar LED light?

While installing your solar lights, care should be taken to choose an area that is shadow-free and place them in such a way that the lights can offer their best on non-sunny days.  Also, make sure that your solar panels are clean without any debris, dirt or dry leaves, for them to absorb sunlight effectively.  A solar light with the right technical specifications, when fully charged, can last up to 15 hours and if the components used are not of good quality, the performance of the solar lights can be affected unfavourably on a non-sunny day.