Solar light is meant to be charged by the sun.
But what do you do when there is no sun or if your solar lights aren’t getting enough natural sunlight?
In this article, we will go through how solar light works and 10 ways you can charge solar lights without the sun.
So without further ado, let’s jump right into it.
Table of Contents
How Do Solar Lights Charge?
Before getting into how to charge solar lights without the sun, let’s take a quick look at how solar lights charge.
First of all, you need to understand that electrical energy is nothing but a flow of electrons.
If you have enough free electrons flowing through the material and you were able to guide them in a particular direction, you have electricity.
Now, solar panels are made of a semiconductor material, usually silicon.
And silicon is known for having 4 electrons in the outermost shell, meaning that these electrons are far away from the nucleus, so they can easily be knocked loose and start flowing.
All we need is something that can give these electrons some energy to break free from the nucleus’s magnetic force and start flowing.
And that’s where visible light comes in.
Visible light is made up of small particles called photons, and these photons have energy.
When a photon hits an electron, it passes some of its energy to the electron in a process known as the effect of the photovoltaic cells.
So if a photon with enough energy hits an electron, the electron will break free from its atom and start flowing freely through solar panels.
And the more photons hit the panel, the more electrons are freed and we can use wires to direct all these free electrons to create an electric current that we can then use to charge our solar batteries.
Think of photons as tiny balls being thrown at plastic bottles (electrons), if you throw the balls with enough force, they’ll knock the bottles off their stand (break free from their atom) and the bottles will start rolling around (electrons flowing freely).
Not so complicated, right?
All we need is photons with enough energy and we can full charge your solar lights.
Now, do you notice that I said light and not sunlight?
That’s because all kinds of light are made up of photons, not just sunlight.
So as long as our light source has enough energy, we can charge our solar light without any sun at all.
And in the next section, we will go through some of the best ways to charge our solar lights without direct sunlight.
How to Charge Solar Lights Without Sun?
There are many ways to charge solar lights without sun, including using LED light bulbs, fluorescent light bulb, incandescent lights bulb, and even the light from a fire or a candle.
1. Indirect Sunlight
Direct sunlight is the most efficient way to charge solar lights because the more intense the light, the more photons with higher energy levels will hit solar panels.
But who said that you can’t charge your solar lights if it’s a cloudy day or gloomy outside?
Even in cloudy weather, the sun is still shining and sending photons to Earth. We are just not receiving them directly because they are being diffused or scattered by the clouds.
So if it’s gloomy outside, just gently clean your solar light with a wet cloth to make sure there is no dirt or debris blocking the photons from hitting the panel, and then angle your solar lights so that they are direct sunlight because solar panels work best when they are perpendicular to the light source.
Note: If you are using solar lights in winter, make sure to take them inside during heavy snowfall as the weight of the snow may damage your solar lights. Also, if your solar lights have an IP rating of less than 65, it’s advised to store them over the winter.
How to Install Solar Panels a COMP...
2. Mirrors
Solar lights can still charge in shade but at a much slower rate.
But if you have access to mirrors, you can use them to reflect sunlight onto your solar panels to increase the light intensity and charge your solar lights faster.
I have to say that this isn’t the most effective option because you need to constantly adjust the mirrors as the sun moves throughout the day but it’s something to keep in mind.
3. Battery Charger
The whole point of solar panels is to charge solar batteries, so why not just use a regular battery charger instead?
Just get the solar batteries out of the solar lights and charge solar lights with a regular battery charger.
It’s not as eco-friendly but it gets the job done in a pinch.
You can also replace your solar light’s battery with a bigger one as long as it has the same voltage.
4. Dual Charge Option
Some solar lights come with the option to charge using both solar powered lights and regular electricity through an outlet.
So if you are in a pinch, just plug the solar lights into an outlet and charge them that way.
Fully charging your battery can also make your solar lights brighter.
5. LED Lights
Remember when we talked about how photons have energy that can knock electrons free from their atoms?
A 2015 study found that solar panels produce the most electricity when they are hit with yellow light or any light with a wavelength between 600 nm to 700 nm (yellow, orange, and red.)
So if you have access to yellow LED lights, those are the best option for charging your solar light without the sun.
Obviously, the more intense the LED light, the faster it will charge your solar lights, so try to get high-powered LED lights or multiple LED lights to aim at your solar panel.
6. Fluorescent Lights
Most of the light emitted by fluorescent lights falls within the 400 nm to 700 nm range, making them another viable option for charging your solar light without the sun.
They are not as efficient as yellow LED lights but it’s your second-best bet.
7. Incandescent Bulb
Incandescent light bulbs emit a spectrum of colors, including yellow.
However, they do emit a lot of infrared light which is not very effective for charging solar light.
Infrared light also generates a lot of heat, which is actually bad for your solar panel because when the temperature rises, the electrons bounce around more, reducing your solar panel’s efficiency.
But if you don’t have access to yellow LED lights, incandescent light bulbs are still a decent option for charging your solar lights without sun.
8. Heat Lamps
Heat lamps can also charge your solar lights but they are the worst option there is.
Almost 99% of the light emitted is above 670 nm.
This leaves you with just 1% of the light being in the effective range for charging solar lights.
Not to mention, heat lamps also generate an incredible amount of heat (they are called heat lamps for a reason) and that can damage your solar panel.
9. Moonlight
Believe it or not, even moonlight can charge your solar panel.
Most of the light from the moon is centered around 400 nm.
This means it’s not very effective for charging your solar lights but on a clear night, the moon can still provide some charge.
10. Fire
Yes, you read that right.
Fire can actually charge your solar light.
But as you guessed, it’s not the most efficient or safe option.
Campfires and candle flames are about 1900 kelvin, so the light emitted from them is primarily in the infrared and red spectrum, with just a little bit (less than 1%) in the yellow range.
So the solar panel can hardly generate any electricity but if there is no other choice, go for it.
Just make sure to keep a safe distance and not let the fire get too close to your solar panels as it can melt or damage them.
FAQs
Can Solar Charge Without Sunlight?
Yes, you can charge solar panels without sunlight. All you need is a powerful light source, and your solar panels will be able to generate electricity and charge your battery.
Can Solar-Powered Lights Be Charged Indoors?
Yes, solar power lights can charge solar lights indoors, as you don’t need direct sunlight to charge them.
Can You Charge a Solar Light With a Flashlight?
Yes, you can charge a solar light with a flashlight. However, solar panel won’t be able to generate a lot of electricity to keep your lights running all night.
How Do I Charge My Solar Battery at Night?
You can shine an artificial source of light, preferably high-power, yellow LEDs on your solar panels to charge your solar battery at night. You can also charge your solar battery using another battery or a battery charger.
How Long do Solar Lights Stay on at Night?
Depending on the amount of charge the solar lights were able to gather during the day, they can stay on for up to 12 hours at night but in reality, most solar lights will turn off automatically after 6-8 hours.
Conclusion
Charging solar lights without sun may not be as efficient but with these alternative options, you can still gather enough light energy for your solar lights to work at night.
Just remember to keep safety in mind and always prioritize direct sunlight or yellow LED lights for charging your solar lights.
FAQs
How can I charge solar lights when there is no sun? ›
You can charge solar lights without sunlight while placing solar panels directly underneath a household light to charge them speedily. Place the solar lights close to the artificial lighting or incandescent bulb to charge solar lights without the presence of sunlight.
How else can you charge solar lights? ›There are two major ways to charge solar landscape lights: exposing them to sunlight or plugging them in at night. Exposing solar landscape lights to sunlight is the best way to charge them. The sun provides enough light to power them without a battery.
Can you charge solar powered things with a flashlight? ›Yes, you can – artificial light (eg flashlight) is capable of charging your solar lights. The speed that the flashlight will charge the solar light depends on the brightness. An average flashlight emits 100 lumens, so it will take much longer to charge your solar light as compared to being outside.
Do solar panels charge on cloudy days? ›Yes, solar panels still work in cloudy weather — they just might generate less power, depending upon the quality and efficiency of your panels.
Can solar lights charge through windows? ›The quick answer to this is yes. Solar panels can indeed work through glass windows or windshields. However, is it enough for your solar panel to work? While you can utilize Solar panels through glass windows, their effectiveness will be far lower than when installed outside.
Can you recharge batteries for solar lights? ›If you're developing your own solar lights, rechargeable batteries can be a viable option. What's important to remember is that switching up battery types isn't a good idea for the overall performance and longevity of your solar lights.
Can solar powered lights be charged indoors? ›Can I Charge Solar Lights Indoors? For lightweight solar lights, you can definitely bring them indoors to charge. You can use regular light bulbs, or by placing them near windows. You can even charge them using your laptop or solar power banks if they are built with a USB charger.
Can solar lights charge a phone? ›with solar power works in one of two ways: A solar panel charges a rechargeable battery, that in turn charges your mobile. This means you can charge your phone even when there is no sunlight - at night for example - so long as you've charged your battery during the day.
What is the best light to charge solar panel? ›First, the best light source for any solar energy experiment is the sun. Cloudless skies are ideal. However, depending on where you are located and when the curriculum calls for learning about solar energy, you may not be able to go outdoors. Incandescent light bulbs (the kind with a filament) are the next best choice.
Do solar chargers work in the shade? ›Solar panels work best in direct sunlight, but they can also work on cloudy days and in partial shade. This is because photovoltaic (PV) panels use particles of light, called photons, to generate electricity. Photons are present in direct and indirect sunlight, so solar panels can operate in both conditions.
How can we generate electricity at night? ›
- Solar panels can now keep generating power even after sunset. ...
- Thermoelectric generators can produce power using the temperature difference between cooling solar panels and the surrounding air. ...
- Solar panels need to be cleaned regularly to ensure the highest possible level of power generation.
Yes, a solar system's “amount of electricity generated” lowers during rain or clouds. However, the system still generates energy. Solar panels are waterproof components, so one does not have to be concerned with water damage. In fact, hard rain can be beneficial by naturally washing away dust and pollen.
Why do my solar lights not work at night? ›A possible reason for your solar lights not working properly is the batteries that you're using. The solar batteries may not be receiving enough charge or they are not holding it. If the solar lights work with regular batteries then the problem is either with the rechargeable batteries or the solar panel.
How can I charge my solar battery at home? ›The simplest possible solar battery charging circuit is just to connect the positive wire from a solar panel to the positive battery terminal, and the negative solar panel wire to the negative battery terminal. This was the main practice back in the day, and will quite happily charge a battery!
How long does a solar light take to charge? ›If the battery is empty, solar lights typically take between 4 and 10 hours of sunlight to fully charge. If they are placed in an area with full exposure, lights installed in the morning will most likely work that night.
What to do when solar lights stop working? ›- Check that they're turned on. ...
- Check that there's not a pull tab on the battery. ...
- Cover the panel to test the light. ...
- Ensure the solar panel is clean. ...
- Make sure the solar panel is positioned correctly. ...
- Test with regular batteries if possible.
Clear nail polish is perfect for rejuvenating plastic-covered solar cells that have become weathered and dull.
Why do solar lights stop working so quickly? ›In case your solar light does not stay on for long, then it is most likely due to degraded batteries which are not performing well after being used for a long time. You can fix this issue by getting new batteries for your solar lights.
Can you use vinegar to clean solar panels? ›Get ¼ cup of vinegar and mix it with two cups of water and half a teaspoon of liquid detergent or any non-abrasive soap. Pour that in a spray bottle, and you have yourself a cleaning solution for your solar panels. Easy as!
Do you need sun to charge solar lights? ›The short answer is – yes! Although direct sunlight is key to charging solar panels, they continue to charge even on cloudy, overcast days. Sol's innovative lighting systems and products, for example, are designed to work for at least four days with no direct sunlight!
Do solar USB chargers work? ›
A: Absolutely. Without a question, a solar powered phone charger needs direct sunlight for the electric current to flow through it. But that does not mean you'll be out of power if the sun isn't shining. Your solar charger will still work in cloudy conditions but at marginally reduced efficiency.
How do I know when my solar battery is fully charged? ›Using a hydrometer is still the quickest and simplest way to determine the state of charge of the flooded lead-acid batteries in your solar battery system. One of the advantages of a flooded lead-acid battery is the ability to quickly determine the battery's state of charge.
Does the sun have to be out to charge solar panels? ›7. Solar panels do not need direct sunlight to work. Even though maximum efficiency is reached when the sun is shining, electricity is still produced on cloudy days and during winter. On the other hand, no electricity can be produced at night, but a storage system can solve this problem.
Can solar panels work with moonlight? ›Electricity Generated by Your Solar Panels at Night Is Minimal. Seeing as moonlight is just sunlight reflected off of the moon, you will be happy to hear that the answer is yes: solar panels do technically work with moonlight.
Do outdoor solar lights need to be turned on to charge? ›Many solar powered lights will still charge if they are not turned on, and by turning them off you actually allow the battery to get a full charge over several days of sunlight. It is an idea to do this regularly with solar lights.
How do you charge a solar watch at night? ›A solar watch cannot be recharged in the dark. Under the following situations, the energy is likely to run out, resulting in stoppage of the watch. The watch is concealed under a sleeve. The watch is used or stored under conditions where it cannot be exposed to light for a long time.
Will solar panels charge at night? ›Solar panels do not produce energy at night. The photovoltaic cells in solar panels must have sunlight to create electricity.
Does heat charge solar panels? ›Some solar panels do use the sun's heat to generate electricity, and these are known as thermal panels. The light from the sun heats up the panels which can be used for household hot water or to generate steam and electricity.
How long to charge outdoor solar lights? ›If the battery is empty, solar lights typically take between 4 and 10 hours of sunlight to fully charge. If they are placed in an area with full exposure, lights installed in the morning will most likely work that night.
Do solar lights work in the dark? ›Solar lights require daylight to get a substantial charge because this energy source relies on photovoltaic impact – a light sensor detects when it's dark, and nighttime illumination becomes activated. But again, the sun doesn't have to be fully present before solar cells receive the charge they need.
Can solar lights work Indoor? ›
As discussed above, solar lights can be used indoors as long as they are installed at a place where they receive sunlight consistently. Indoor solar lights are ideal lighting options during power outages as long as they are fully charged.
Can you simulate sunlight for solar panels? ›This may come as a surprise but, technically, yes. Solar panels can charge with other forms of visible light besides sunlight. Artificial lights such as incandescent fluorescent bulbs can be used to charge solar cells, provided the light is strong enough.
Why wont my solar lights charge? ›A possible reason for your solar lights not working properly is the batteries that you're using. The solar batteries may not be receiving enough charge or they are not holding it. If the solar lights work with regular batteries then the problem is either with the rechargeable batteries or the solar panel.
Is there a way to get solar energy at night? ›Solar power in the dark
In a breakthrough promising 24-hour reliable renewable energy, scientists have tested panels that keep producing power even when the sun goes down. Conventional solar panels only work in daylight, so you need expensive battery storage to enable solar-produced power to be used at night.
A Solar watch runs out of energy. What to do? Try to recharge it often, and make sure to expose it to sunlight by a window for 5-6 hours once every month with the dial facing the sun.
Will a regular light bulb charge a solar watch? ›Your solar-powered watch/clock can be charged indoors by the light from a fluorescent lamp or incandescent lamp. However, charging your solar-powered watch/clock by indoor lights will take longer than charging it by the sunlight.