There is no better way to reduce your carbon footprint and save a few dollars a month than using solar-powered lights. However, since solar lights depend on sunlight, some people may have doubts about their effectiveness. So, does solar lights need direct sunlight?
For this reason, in this article, we will clear all your doubts by answering the most asked questions including:
- Do solar lights need direct sunlight to charge?
- Can solar lights charge in the shade?
- Will solar lights charge through glass/windows?
- Can solar lights be charged indoors?
So, without further explanation, let’s jump right to the first question.
Do solar lights need direct sunlight?
To answer your question, first you need to understand how lights work
The main component of solar lights is solar panels, which are placed above the lamp. They act as semiconductors that can capture solar radiation (photons) and convert it into electricity.
Solar radiation is everywhere around us and for this reason your lights don’t need direct sunlight to charge.
However, it is important to mention that although solar lights do not require direct sunlight, you are better off installing the lights in a sunny location.
It will maximize exposure to solar radiation and generate more electricity, so your lights will run longer.
Can solar-powered lights work in the shade?
The short answer is yes, the light can be charged in the shade
Shade’ is defined as the comparative darkness/coolness as a result of shielding from direct sunlight.
As you can see, it is therefore a rather broad term that covers a lot of things. The shade can be very dark with almost no light coming through or it can be slightly less bright than in direct sunlight.
The most important is; The less light that passes through, the less chance there is for photons from the light to reach the panel and generate electricity.
So, if your panel is behind a wall that is heavily hidden for an extended period, that is different from being under a tree. A tree causes shade but some light still gets through. You know this because when you walk into a forest, even if all the trees are leafy and there are many trees, you are not sure to be plunged into absolute darkness.
In detail, when the light is covered by shade, there is practically not much light, the panel will generate less electricity. And as a result, your lights will dim and stay on for less hours at night.
Will solar lights charge through glass/windows?
The lights will continue to charge through the glass, but they won’t be very efficient.
The reason is that glass tends to reflect sunlight, resulting in solar panels absorbing less sunlight, thus producing less electricity.
In other words, they will still work, but their performance will be degraded.
Can solar lights be charged indoors?
As mentioned before, solar lights can charge indoors. However, if you want to use the lights in your home with maximum efficiency, you have 3 options:
- Place the solar lights outside or in a sunny place during the day, then move them inside at night.
- Charge your lights indoors with regular artificial lights.
- Choose indoor solar lights designed to separate the panels from the light, so you can place the lights’ panels outside in the sun and still keep the light inside.
An experiment on the placement of lights, let’s see which is the most optimal:
I ran several tests with different types of solar lights in different shade situations with all that in mind. For all these situations, I first wait for the battery to drain:
Scenario 1 – Leaving in direct sunlight all-day
I was expecting the best results here, I placed the light in the middle of the garden where it got almost 8 hours of sunlight and stayed on all night with no problems.
Scenario 2 – Half day direct sun half-day in total shade
In scenario 2 I place the light in a position where it will receive direct sunlight for about half a day but then when the position of the sun changes it will be hidden behind the fence.
Again, the light stays on all night, it may not have fully charged the battery, but it has changed enough to last all night.
Scenario 3 – Under a tree on a sunny day
Still on a sunny day (as above), I placed the light under a large oak tree, thus placing it in the shade most of the day.
The result this time was not satisfactory, the light was still on but turned off after about 4 am.
Scenario 4 – A cloudy day, no shade
On a cloudy day with no shade, the lights stay on all night (more than 8 hours).
How much light do solar lights need to illuminate all night?
From my testing using a small lamp above, it is clear that all day in direct sun is not necessary to keep the light on all night, as just 4-5 hours a day is enough lighting all night. It also shows that if there is a lot of shade covering the lamp, energy harvesting efficiency is also lower, and the lamp’s lighting time is also shorter.
Of course, this will vary depending on the type of light, panel type and battery type. There is no amount of time or amount of sunlight that ensures your lights stay on all night.
Most manufacturers claim that 8 hours of direct sun exposure will give 12 to 15 hours of charging time.
In this article BSLG has answered your question: Does solar lights need direct sunlight? Solar lights will charge in the shade but it’s best to check the mounting position of the light so it can get the best sunlight, change the position and see what happens.