How Do Solar Lights Work?

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Using the sun to power our lights seems like a great idea but how do solar lights work, exactly?

How can solar lights continue shining late into the night, long after the sun goes down?

Well, we’re here to let you in on the secret not only of how solar lights work but their benefits as well.

First, we need to understand what makes up solar powered lights.

From here, we can get into how exactly a solar light converts sunlight to power and why this may be extremely important for our future.

What Components Make A Solar Light?

Four main components make up a solar light. These include a battery, a solar photovoltaic (PV) panel, electronic controls, and, of course, light.

During the day, when the sun is shining, the solar panel can harness the sunrays and create electrical energy.

This energy is then used, either straight away to power the light or stored via the battery. This stored energy can then be used for power when there is no sunlight.

These solar lights can have batteries with various sizes of capacity. This depends on the function of the solar light. If it needs to power a solar light with high intensity for long periods of time, then the battery will be bigger.

The introduction of the Light Emitting Diode (LED) light has reduced the capacity required for these solar panel lights. They are extremely effective at providing a powerful source of illumination without draining the energy stores. This means the battery and solar panel size can be much smaller, which is great for transportability. It also means that the overall price of these solar lights is much lower.

The electronic controls within these lights are pretty impressive. Because solar lights are often used for outdoor solar lighting, they need to turn on automatically. This requires a system that can detect light levels outside and switch on when it becomes dark.

The internal control electronics also play a role in moving energy from the solar panels to the battery.

But How Do Solar Lights Work?

So, we’ve covered what makes up a solar light but what is the science behind it?

How do solar lights actually work?

The energy produced from these solar panels is a result of the photovoltaic effect.

The solar cell is responsible for converting sunlight into electricity that powers the light.

The photovoltaic panel is another name for a solar cell and comprises several layers of crystalline silicon.

These layers produce areas of negatively charged electrons with positively charged spaces in between. When sunlight enters the photovoltaic panel, the negatively charged electrons become excited, which drives the electrons into the positively charged spaces.

This motion creates a stream of electrons that can be used as a current of electricity. This electricity travels along wires within the solar cell that can power the LED light.

The electricity produced can also be routed to a battery which then becomes charged. This allows enough energy to be stored to power the light for hours in darkness.

How Is Solar Energy Stored in Solar Lights?

You might be thinking, surely outdoor solar lights are only useful when the sun is up. However, there is a clever technology that allows these lights to function even in darkness. The solar cell is wired directly to power the light – but it also stores some of the electricity produced.

This is done through the use of a solar battery. The battery is continuously charged throughout the day by the sun.

As the sun goes down, the solar cell converts sunlight at a lower rate, and another source of electricity is required to continue powering the light.

When there is no longer adequate sunlight to power the solar light, the source of electricity switches to the battery. Good solar lights are capable of creating enough solar power to last the entire night.

When the sun rises, the source of electricity switches once more, and the sun becomes the main source of power.

Some might not have a powerful enough battery to last the entire night for less efficient solar panel lights. Most solar lights will have no problem during the summer when the sun is up for much longer. This gives plenty of time to fully charge a battery to power the light through the short night.

However, during winter, these less powerful solar cells may struggle to receive enough sunlight to charge the battery fully. This may result in some of these outdoor solar lights cutting out during the long nights.

Another thing to think about is the prevalence of snow during the winter. Snow can block a solar panel which will prevent the battery from being charged.

What Are The Benefits Of Solar Lights?

Solar energy is, without a doubt, an important technology both now, and in our future.

Solar panel lights are beneficial in providing light sources to areas where it’s hard to connect to a power grid. They are a great alternative that is a lot more eco-friendly and cost-efficient.

Suggested Reading: 7 Benefits of Solar Lights

By providing light to places that are usually pitch black at night, security and comfort are increased as well as safety.

Cost Efficient

Solar panel lights cost the same to install with respect to the poles themselves.

However, solar lights do not require the same underground network to connect them to power. This can be very expensive, especially if there are barriers in the way, such as roots or other piping systems. In fact, we love solar lamp posts as a far more cost effective option instead of digging trenches for wires.

Once installed, solar lights work without adding to energy bills. This is perhaps the biggest money saver. Over multiple years, the amount of money saved on the energy bill can certainly be substantial.

Apart from the required battery change once every 5 years, no other maintenance is necessary.

The lifespan of all the other components is around 15-30 plus years. This means that once installed, the maintenance required for solar panel lights is actually very low.

Environmentally Friendly

One of the most important factors that convince people to switch to solar power is that it’s much more eco-friendly.

Solar cells produce no harmful emissions. Unlike traditional sources of power, solar lighting is clean.

In addition to being a lot less harmful to the environment, it is also renewable. The source of energy is the sun and therefore is not going to run out any time soon.

The same cannot be said for fossil fuels, where the levels have been depleting at an alarming rate. Less harmful sources of energy in communities means reduced damaging emissions and cleaner air for everyone.

Reducing how much we rely on fossil fuels and other traditional energy sources will improve our quality of life. Over time, people will begin to use clean energy more.

It starts with people using solar garden lights and progresses to electric vehicles in the future. People should strive for a greener way of life that reduces harm to both the environment and each other.


Solar lights are regarded as being very safe, especially for outdoor lighting. The main risk that comes with most solar lights is the potential of a fire. The main cause of fires in solar lights is a result of the battery malfunctioning.

The battery in a solar powered light stores energy supplied from the sun. If these batteries are made with cheap materials, then they can pose a risk.

Solar lights normally produce a small amount of heat. If the batteries are cheap, then there is a risk that the light will become too hot and cause the outer casing to melt.

This becomes more of a problem if the solar lights are kept near flammable materials.

For example, outdoor lighting that is near dry bushes or close to wooden structures. It should be emphasized that fires are rare when it comes to solar lights.

The main takeaway is this – don’t cheap out and go for the least expensive option on the market. Make sure to do your research and that you are buying good solar lights that are reliable.


Why Are My Solar Lights Not Working?

There are several things to consider if you find that your solar lights are not working properly. First of all, before you throw your lights away or rush off to buy new batteries, make sure to check that the light is switched on.

This can seem like an obvious thing to check; however, you’d be surprised how many people forget this.

Not all solar lights have switches, so some people may think this is standard for all lights. However, this is not the case, and if you have a look, you may find an on/off switch somewhere.

The next step is to make sure the surface of the solar panel is clean. Sometimes, a solar light might not work because it can’t receive direct sunlight.

Finally, the most common problem is the batteries. Try replacing them, and if that doesn’t work, it might be time to check if the lights are under warranty.

Should I leave My Solar Lights On All The Time?

Solar lights are powered by the sun and are designed to provide light at night. A good solar light will get enough charge throughout the day to provide illumination through the night. So the answer is yes, you can leave solar lights on all the time.

If you find that your solar light doesn’t last the entire night, then you can switch them off during the day. This will allow more power to be stored in the batteries and increase how long they last at night.

How Long Do Solar Lights Last?

The batteries, on average, have around a five to seven-year lifespan. This means that the only real maintenance you have to do will be once every five years. This maintenance should include a battery change, a quick visual check of the panels, and some cleaning to ensure nothing is wearing.

All of the other parts of a solar light last, on average, around 15-30+ years. This means that once you install the solar lights, they can last a very long time with little effort to maintain them.

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Eric Thomas

Eric is the founder of the Simple Solar Living team and serves as our CEO & Chief Solar Officer. He is passionate about solar powered products and DIY solar projects, and took part in the Solar Energy Technician program at Bryan University. Eric is committed to sharing the benefits of going solar and is a steadfast advocate of clean renewable energy.