Can solar lights charge through windows?

can solar lights charge through windows?

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If you want to know that can solar lights charge through windows? than this post is for you.

In this post, I did a short experiment to check whether solar lights can be used in indoor conditions or not?

Short answer: Yes, solar lights can charge through windows. But will you be able to get enough light from them? Let’s look.

can you charge solar lights inside?

The first question that needs to be answer is that Can I charge solar lights indoors?

To know this I did a short experiment with a 24V solar panel. I placed the panel exactly behind the window with sun rays falling on it and checked its reading on a multimeter. Here are the readings for you.

TestStandard(at STC)Behind Window
Open Circuit Voltage22.3V20V
Short Circuit Current1.82A.55A

*Here STC means Standard Test Conditions for solar panels. It is the industry standard on whose value the solar panels are tested. It is 1000 W/m2.

From the experiment I found out that although the voltage remained almost the same the current is slashed to one-third of the original readings when placed behind the window.

This means that very less output than the normal. With this one-third output you can imagine how the solar lights will work and perform.

So you can charge solar lights inside but don’t expect much from their performance.

Do solar lights charge up through glass?

The experiment I did above was done using a glass window. The glass was not tinted. It was a normal glass.

I can say that yes solar lights can charge through glass but it will be hard to get some quality output unless they are placed near the window with right direction and sunlight falling on the panels.

If you want to light your room without electricity then you can use them placing near the windows.

Can you charge solar lights with artificial light?

Since we are using solar lights in indoor conditions therefore it becomes very important to know that is it possible for charging solar lights without sun?

For knowing about this fact it I again did a short experiment whose video recording is available below.

YouTube player

In the experiment I used three variables to test: a candle, a 9 watt led bulb and a 100 watt incandescent bulb. The objective was to light up a small led bulb which I had connected to the panel.

Here are the results:

1. candle

When I used the candle to light the bulb, the solar panel was able to generate voltage and current. But the light from the led bulb was dim.

This implies that fire can be used to charge solar applications but it is not a practical approach in my opinion.

2. led bulb

Led bulb was much bright than the candle but the result was not as expected. The light of the led light was very very dim as compared to the candle.

Led bulb failed to generate sufficient electricity in solar panels to light the bulb.

3. Incandescent bulb

In the third case I used an Incandescent lamp bulb. The bulb was very bright almost like the sunlight. It was warm too.

When I brought the filament bulb near the panel, the light bulb in the experiment lightened up brightly.

It was just like if I had used normal electricity to lighten it.

This made me to think that the Incandescent bulb is able to generate the required amount of heat and light which can generate electricity in solar panels.

From this experiment I came to the conclusion that Yes, solar lights can be charged with the help of artificial lights. But doing this may increase your electricity bill.


Although solar lights can be charged through the windows but I don’t think they will work as normal.

For them to work either they will need to be placed near the windows where sun rays are passing or will require artificial lights to charge.

I don’t find any merit in both of the methods. But if you have no other option and want solar lights for indoor use than I will suggest you to go with a wired solar light.

Find more helpful content about window solar lights on my page: solar lights for windows