How Do Solar Lights Work? Types, Uses, and Environmental Impacts
Discover your solar lighting options and which products are designed to last.
- Columbia University Graduate School of Journalism
- University of California, Santa Cruz
- Western New Mexico University
Autumn is an independent journalist and educator who writes about climate, wildlife, biodiversity, and environmental justice and policy.
Olivia Young is a writer, fact checker, and green living expert passionate about tiny living, climate advocacy, and all things nature. She holds a degree in Journalism from Ohio University.
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Solar lights absorb the sun’s energy during the day and store it in a battery that can generate light once darkness falls. Like solar panels used to generate electricity, solar lights use photovoltaic technology. They can be used for a variety of indoor and outdoor purposes, from lighting streets to illuminating homes and gardens, and are particularly useful in places and circumstances where it isn’t possible to connect to a central power grid.
How Solar Lighting Works
Solar lights use photovoltaic (PV) cells, which absorb the sun’s energy and create an electrical charge that moves through the panel. Wires from the solar cell connect to the battery, which converts and stores the power as chemical energy until it’s needed.
The battery later uses that energy to power an LED (light-emitting diode) bulb. The diode is a semiconductor that allows electrons to pass between its two points, creating electromagnetic energy in the form of light during hours of darkness.
LED technology generates light up to 90% more efficiently than incandescent and fluorescent lighting, making it ideal for solar lighting systems. Rather than burning out like a traditional light bulb, LED bulbs simply dim over time. But their typical lifetime is far longer than a traditional bulb: tens of thousands of hours versus the 1,000 hours of an incandescent bulb, or 3,000 hours for a halogen bulb.
Types and Uses of Solar Lighting
Solar lighting sales have taken off in response to the global demand for less carbon-intensive energy sources and as a strategy for increasing energy resilience in the face of extreme weather and other natural disasters that leave centralized power systems vulnerable. It is also helping to meet the energy needs of developing regions where connection to a centralized electricity grid is difficult or impossible.
Solar lighting provides cheap, attractive, low-maintenance illumination for homes, businesses, and public infrastructure while reducing the environmental impact. When we think about solar lighting, there are two broad categories: indoor and outdoor solar lights. Here are a few of the many solar lighting uses.
Street and Parking Lights
Investment in renewable energy, energy efficiency, and other sustainable planning approaches have led to Rapid growth in solar street lighting for towns and cities.
Solar-powered lamps provide cities with a cheap way to illuminate streets, sidewalks, and parking lots, creating better safety for pedestrians and drivers alike. They typically include a lamp post and fixture powered by a small solar panel array attached to the post. This makes each lamp self-contained and able to generate carbon-free electricity without requiring connection to a central grid and has the added benefit of reducing overall installation costs.
Traffic Lights
Solar-powered traffic lights are not only economical; they can save lives during power outages and in places lacking reliable electricity sources by ensuring consistent, uninterrupted operation of traffic signals.
Solar Sign Lights
We sometimes take for granted the illumination of billboards, street signs, and storefront signs, but proper lighting is quite important for achieving effective signage. Solar sign lights provide a way for businesses and public services to highlight essential information while saving money on electricity. They come in a variety of brightness levels depending on the needs.
Solar Floodlights
During and after a natural disaster or other circumstances that cause power cuts, solar-powered emergency floodlights can help crews make repairs under challenging conditions without the need for generator-powered lighting system. These powerful solar lights can also be employed in home workshops, garages, yards, and businesses that need extra security or stronger illumination. Some are security lights come with timers or sensors to ward off would-be troublemakers.
Garden Lights
Solar lights have become extremely popular for use in gardens, patios, and outdoor dining venues. They provide both safety and aesthetics, and come in a wide array of styles and products.
Lawn lights can highlight attractive garden features like flower beds, trees, or sculptures. Pool lights illuminate water elements like swimming pools, ponds, and fountains. A string of solar lights can be stretched across a patio, porch or between trees to add a touch of festive ambience. Ground lighting along a walkway, driveway, or steps improves safety and provides an attractive design element.
Solar Candles
Suitable for both indoor and outdoor use, flameless solar-powered candles and torches are a safe alternative to a real candle. Modern designs feature realistic flickering “flames” that resemble the real thing but avoid risk of fire and spilling messy hot wax.
Solar Desk and Table Lamps
A solar desk lamp is a great accessory for a home office. For one thing, it’s cordless and thus completely portable, which makes it possible to set up a remote workstation virtually anywhere, indoors or outdoors. Designs for desk lamps range from small clip-on book lights to sleek and sturdy tabletop varieties. Table lamps, meanwhile, create ambience as they produce illumination.
Like other types of residential solar lights, some models come with a built-in solar panel while others must be connected to an external photovoltaic panel, but neither type requires direct sunlight. The energy generated by the small PV panel gets stored in a battery, which provides several hours of light before the lamp will need a recharge.
Environmental Benefits and Drawbacks
An investment in high-quality solar lights can provide years of virtually carbon-free lighting for homes, offices, parks, gardens, and public infrastructure. It’s a great way for an individual or community to conserve energy and reduce disruptions posed by extreme weather and climate disasters.
For communities that lack centralized energy infrastructure, including many rural communities around the world, solar lighting makes a big contribution to energy independence. It also contributes to public safety by illuminating walkways and streets, reducing traffic accidents, and increasing personal security.
However, solar lighting, like all solar energy systems, has environmental impacts. The batteries and electronic components will eventually become waste, and that waste has hazardous ingredients that must be properly managed in order to avoid toxic pollution. Batteries can contain lead, lithium, plastics, and sulfuric acid; PV panels contain silicon, aluminum, tin, copper, cadmium, and lead; electrical components contain plastics and metals. If not disposed of properly, these substances can pollute the air, soil, and water.
This is a particular challenge in developing countries, where waste management is more likely to be conducted without regulation to ensure safe disposal. The absence of this process can produce e-waste that poses serious threats to the environment. Some countries require or encourage end-of-life recycling of at least some of these products.
Today, there are calls to strengthen such practices and ensure that solar projects everywhere support safe disposal and recycling of solar materials once the components have reached the end of their productive use. Of course, this is important not only for solar but traditional lighting.
Wherever you live, it’s important to research the longevity of your solar lighting products and prioritize quality. Opt for those which are likely to last, so the environmental benefits don’t dwindle.
How to Get Your Solar Lights Working Again
Alora Bopray is a digital content producer for the home warranty, HVAC, and plumbing categories at Today’s Homeowner. She earned her bachelor’s degree in psychology from the University of St. Scholastica and her master’s degree from the University of Denver. Before becoming a writer for Today’s Homeowner, Alora wrote as a freelance writer for dozens of home improvement clients and informed homeowners about the solar industry as a writer for EcoWatch. When she’s not writing, Alora can be found planning her next DIY home improvement project or plotting her next novel.
Roxanne Downer is a commerce editor at Today’s Homeowner, where she tackles everything from foundation repair to solar panel installation. She brings more than 15 years of writing and editing experience to bear in her meticulous approach to ensuring accurate, up-to-date, and engaging content. She’s previously edited for outlets including MSN, Architectural Digest, and Better Homes Gardens. An alumna of the University of Pennsylvania, Roxanne is now an Oklahoma homeowner, DIY enthusiast, and the proud parent of a playful pug.
April 27, 2023 December 6, 2022
Ten reasons why your solar lights may have stopped working, and how to fix them
Solar energy use is on the rise globally. Advances in technology mean that we are becoming increasingly less reliant on using polluting fossil fuels for energy, and are replacing these dirty fuel sources with clean renewable energy such as solar electricity and wind power.
In fact, we can see solar energy in use all around us everyday. Technology such as residential rooftop solar panels, solar chargers for electric vehicles, and solar water heaters can be commonly found in households, and are no longer the rarity they once were.
Among these innovations, solar lights are one of the more popular solar products in use today. Also known as a solar lamps or solar lanterns, these convenient lights are attached to their own solar panels and battery, allowing the light to shine even without being connected to a power outlet.
Some of these solar lights might even come with motion sensors attached, only turning on when movement is detected. By relying exclusively on completely free solar power, these lights allow you to save big on your electricity bills.
However, solar lights are not infallible – they can occasionally stop functioning, and it might be confusing to figure out what went wrong. We’ll run through some of the more common scenarios below which might cause your solar light to fail, and how to get them up and running again.
Fortunately, most of these issues have a simple fix, and only require small re-adjustments to address!
So without further ado, here are some methods which might be able to get your solar light working again.
Shade Your Light Sensor
Yes, we know that this sounds counter-intuitive. Since the solar panel attached to your solar light needs to receive sunlight in order to generate electricity, why should shading your solar light get it working again?
The answer lies in how your solar light is programmed to work. Some solar lights are configured to turn themselves off during the day, and only turn on when lighting levels are low. Electricity produced from its solar panel when the sky is bright is sent to the battery, instead of being used to power the light.
If your solar light’s sunlight detection is overly-sensitive, it might be mistakenly turning off the light even when you want it to shine. This can also happen if there are nearby light sources which make the environment overly-bright at night. By shading your solar panel, you force your solar light to recognize that lighting levels are low and that it needs to give off light, allowing your light to start working again.
Check Your Batteries
Batteries attached to your solar light should charge up during the day, using power generated by the attached solar panel. These batteries usually have a lifetime of around two years, after which they can break down and need to be replaced.
When your solar battery breaks down, it means that energy generated during the day is not stored properly. Your solar light would have no electricity to draw on when it becomes dark, and it simply won’t turn on. Most of the time, all you’ll need is a screwdriver to open up the battery slot on your solar light, and slot in some fresh re-chargeable batteries (make sure that they’re of the same size and capacity) to get your light working again.
Avoid Shadows
Sometimes, the problem might be as simple as an unexpected piece of shade blocking your solar panel from the Sun. Check if some object is preventing sunlight from reaching your solar panel during the day, and stopping it from generating the electricity that your light needs.
Keep in mind that as the Sun moves across the sky during the day, the shadows cast by nearby objects will change accordingly. The Sun’s position in the sky also changes based on the season. Make sure that your solar panels are in the best spot possible to receive the most sunlight each day!
Position Your Solar Panels at the Best Angle
The angle of your solar panels is also key to allowing it to generate enough solar energy to power your light. Finding the right angle can be tricky at times, however, since the optimum angle depends on both the time of year and on where you are in the world.
If you just want to set your solar panels at a specific angle and leave it untouched afterwards, we recommend tilting your solar panels between 30 and 50 degrees if possible. This angle ensures that your solar panels should receive adequate sunlight year-round.
Otherwise, one approximate calculation method for the optimum angle in winter is to add 15 degrees to your latitude, and re-adjust your panels in the summer to have a tilt of 15 degrees lower than your latitude.
Face Your Panels Towards the South
Generally, solar panels can receive the most sunlight if they’re faced towards the South, but only if you live in the Northern hemisphere. This is because the Sun is mostly present in the Southern part of the sky as it moves from East to West everyday.
If insufficient energy production is causing your solar lights to fail, re-positioning your panels to face the South might help.
Check for Water Damage
This issue is usually rare if your solar light comes from a well-known or highly-rated manufacturer, but it can nevertheless be an occasional cause of solar light failure. Luckily, water damage is not always permanent, and your solar light can sometimes start working again once it dries out.
To properly dry out your solar light, make sure to check for and remove any sources of liquid that could have leaked onto the equipment. This includes the light itself along with the attached battery and solar panel. Once the light becomes completely dry under the Sun, it should start working again.
However, most solar lights are only water-resistant, and not completely water-proof. If water has completely seeped into the inner electrical wiring of your light multiple times, it might not be repairable. It’s inevitable for your solar light to become become exposed to rain, but do not allow any part of your solar light to get completely submerged in water.
Restart Your Solar Light
The time-honored method of fixing any electronic device. Sometimes, all it takes to get your light working again is to turn it off and turn it back on.
Clean Your Solar Panel
A dirty or dusty solar panel can also prevent your solar light from receiving enough electricity to work. Dirt and grime on the outer glass covering of a solar panel blocks sunlight from reaching the inner solar cells, which in turn may prevent them from generating enough electricity to power your light.
Usually, a simple wash with water and a solar-panel cleaning solution every three months is more than enough to keep your panels clean. There are however more specifically-tailored solar panel cleaning products out there if you prefer.
Don’t Charge your Solar Light Through Glass
Your glass Windows might appear to be completely transparent, but its a known fact that solar panels work much less efficiently if they can only receive sunlight through a glass window. Unless absolutely necessary, always place your solar light outdoors and allow it to receive direct sunlight.
Reset or Replace Your Lux Sensor
The Lux Sensor is a vital part of your solar light, and it controls when your light switches on. By changing it’s settings, you can make your solar light turn on once it detects light levels dropping below a certain threshold.
Sometimes, an overly-sensitive Lux sensor might be turning your solar light off, even when it becomes dark. This can be fixed by simply adjusting your sensor’s settings.
Other times, your Lux sensor might have broken down completely, resulting in your solar light never turning itself on. If you block all light completely from your light sensor and your light still doesn’t turn on, that’s likely the case. When that happens, the sensor needs to be replaced by a new one to get your lights working again.
Frequently Asked Questions
Why are my solar lights flashing on and off?
Flashing solar lights is often an indication that your LED light isn’t receiving enough electricity. For example, the electrical wiring of your light might be loose, or your solar battery might be almost out of electricity, leading to your lights not working as they should.
How long does a solar light last?
The batteries of a solar light is often the first component to give out, and unfortunately the re-chargeable batteries equipped on a solar light generally only last for one to two years. Fortunately, these batteries are easily replaceable – as long as you can buy new batteries with the same size and capacity to replace your old ones, the other components of your solar light can theoretically last for 20 to 30 years.
Can solar lights be used indoors?
Yes, as long as you have a spot indoors which receives enough sunlight to charge your solar light. Note that solar panels work much less efficiently indoors, however, especially if it is only receiving light through a glass window.
Can my solar light catch fire?
While rare, there have been reports of solar lights over-heating and catching fire. Most of the time, these fires have been a result of overheating solar batteries coming into contact with flammable material. Make sure that you use high-quality batteries with good safety controls that shut off the battery before it overheats, and place your solar light away from any materials that can easily catch fire.
Alora Bopray is a digital content producer for the home warranty, HVAC, and plumbing categories at Today’s Homeowner. She earned her bachelor’s degree in psychology from the University of St. Scholastica and her master’s degree from the University of Denver. Before becoming a writer for Today’s Homeowner, Alora wrote as a freelance writer for dozens of home improvement clients and informed homeowners about the solar industry as a writer for EcoWatch. When she’s not writing, Alora can be found planning her next DIY home improvement project or plotting her next novel.
Roxanne Downer is a commerce editor at Today’s Homeowner, where she tackles everything from foundation repair to solar panel installation. She brings more than 15 years of writing and editing experience to bear in her meticulous approach to ensuring accurate, up-to-date, and engaging content. She’s previously edited for outlets including MSN, Architectural Digest, and Better Homes Gardens. An alumna of the University of Pennsylvania, Roxanne is now an Oklahoma homeowner, DIY enthusiast, and the proud parent of a playful pug.
Sunlight solar light
How to make your outdoor space more inviting
Looking forward to spending time outside, enjoying the spring sunshine and summer breezes?
A modern family-time table
This table is designed to be used, so the materials were chosen for their durability.
Dining table chair proves its worth, after dinner too
The fan-shaped silhouette with its distinctive rounding evoking the Dosina seashell accentuates the chair’s superior seating comfort with the generous embrace of its backrest.
Easter dining decor
One table is drenched in Nicola’s nostalgia for childhood egg hunts and 80s pastels. The second, in the refined aesthetic of adult festivities.
Solar cell lamps
Solar cell lamps provide ambient, eco-friendly light without wires. With manual or automatic activation at dusk, your lighting will extend the evening and frame the patio or conservatory beautifully.
Our Swedish summer evenings are virtually never-ending, but even so, a little extra light adds to the atmosphere and makes you feel like sitting out for longer. Eva Solo solar cell lamps can be placed on the patio table or in the conservatory, suspended from hooks hung on the house, or even placed in trees. You can use the lamps in all kinds of ways and places – only your imagination sets the limit!
ATMOSPHERIC LIGHT THAT EXTENDS THE EVENINGS
Eva Solo has a unique range of solar cell lamps that go by the name of Sunlight. There are lots of different models, and even more uses for them. The range of solar cell lamps includes table lamps, ceiling lamps, lamps on a spike for the garden and lamps with hooks for hanging.
The name of the product range is no coincidence. The energy source is sunlight, and the light from the lamps when you switch them on – or when they turn on automatically in the evening – is bright and strong. The way the glass lampshades disperse the LED light creates the right atmosphere as dusk falls. Use the extra light on the patio or in your conservatory for entertaining friends or just to chill out and enjoy the peace and quiet of the evening.
The Eva Solo solar cell lamps are stylishly designed. The glass lampshades are elegantly domed to disperse as much light as possible, and other details are in elegant anodised aluminium. Unlike in most solar cell lamps, the photovoltaic panels are not visible but are integrated into the design.Automatic charging during the day
A lot of solar cell lamps tend to be quite weak. They require many hours of exposure to light, but give only a modest glow. Eva Solo solar cell lights shine brightly for up to 20 hours based on an eight-hour charge of full sunlight. The battery driving the LED light can take up to 1,000 charge cycles.The LEDs are bright, with up to 15,000 burning hours. In short, you’ll never have to replace the actual LED light in your solar cell lamp.
If you want to use Eva Solo solar cell lamps as ambient lighting indoors, too, you can choose the Sunlight Lounge model. This solar cell-powered table lamp can also be charged via USB. A sleekly styled lamp that will look great anywhere in your home.
AUTOMATIC FUNCTION
Solar cell lamps are mostly used as outdoor lighting in the summer to make the patio or conservatory a bit cosier. However, they can also be useful as general indoor lighting in winter, especially if they are fitted with a twilight sensor. Coming home to a house in darkness after work isn’t very welcoming, but if you have solar cell lights with a dusk sensor, you can make sure it’ll be glowing in your Windows when you open the door. It brightens things up a bit and helps make the dark winter days a little more bearable.
Why Do My Solar Lights Come On During The Day? (Easy Fix)
Solar lights are a new trend these days. They remain switched off during the day and come on at night to provide pleasant, ambient lighting in your backyard, courtyard, or patio. Such lights help lower electric bills by providing off-grid solutions to outdoor lighting and help save the environment. However, like all electrical systems, solar lights are expensive. If your solar lights come on during the day, you might incur huge losses and end up with a problem you didn’t even have in the first place.
So, why do sometimes solar lights come on during the day? There are 5 main reasons why solar lights come on while the sun is shining— defective light sensors, insufficient daylight, dirty solar panels, faulty wires or damaged batteries, and water or moisture penetration.
We will look at each of these reasons in detail in the upcoming sections.
What are solar lights?
A solar light, also known as a solar lantern or solar lamp, is a lighting system that contains an LED lamp, a set of solar panels, a battery, a charge controller, a light sensor, and sometimes, an inverter.
The LED lamp in the light operates on the electricity provided by the battery that charges when the sunlight hits the solar panels’ photovoltaic cells.
Each solar light in your house may have its own solar panel system, or you can connect all the solar lights to a single solar panel. The resulting electricity would be the same, depending on the total panel size.
During day time, the solar lights are supposed to stay turned off because who needs outdoor lighting when the sun is shining bright? However, as soon as it starts to get dark, the solar lights’ sensors recognize the absence of sunlight, and the LED lamps light up automatically, using energy stored in the batteries.
Solar lights are a convenient, eco-friendly, and cost-effective way to light up your backyard, patio, balcony, or street at night. However, like all electrical appliances, they can also malfunction at times.
Reasons why solar lights come on during the day
Let us help you understand why your solar lights come on during the day when they’re only supposed to come on at night.
Defective light sensors
The sensor in your solar light may be faulty or damaged. Maybe you or your pet has knocked over the solar light several times, or perhaps, the lamp has taken a hit, causing damage to the sensor inside the solar light. Check your light to see if the sensor is broken or cracked.
Not enough sunlight
Solar lights need plenty of sunlight during the day to charge and store power inside the battery. The sensor inside a solar light also needs sunlight not only to turn on but also turn off when the sunsets.
Your solar lights might be coming on during the day because they are not receiving enough sunlight, causing the sensor to believe that it is night time, which means it is time for the LED lamp to start shining.
Dirty solar panels
A dirty solar panel with debris, tree leaves, or dust will prevent the sunlight from charging the battery, but most importantly, it will confuse the sensor inside the solar light that cannot tell whether it is nighttime or daytime. When dirt blocks the panels, the sensor assumes it’s night time, and the lamp starts shining.
Faulty wires or damaged batteries
Another reason why your solar lights come on during the day could be because of the fault in wires or damages caused to the solar storage battery.
Outdoor lights can have faulty wires as pests, such as squirrels, can chew them. If the company has manufactured the solar light poorly, faulty wires could be a production problem as well.
Damaged batteries can also cause your solar light to function during the day. The battery is supposed to ensure that your solar light switches off during the day. However, your lights may turn on because the performance of batteries may decline over time.
Moisture/Water penetration
Did your area have a rain spell recently? Or did you clean your lights in the last few weeks? Water or moisture penetration can affect the ability of the light sensor to perform.
If the air is too humid, water can get inside your solar lights. Even though manufacturers build solar lights in a way that allows them to withstand all environmental conditions, water can seep inside gradually.
Easy ways to fix solar lights that come on during the day
If your solar lights come on during the day, here are 7 easy ways in which you can fix this problem:
Check the light sensor
The first thing you must do when your solar light turns on during the day is to turn it off and check the sensor. If you notice cracks on the sensor, the solution is apparent; you must replace it with a new one.
However, if you cannot see a visible fault in the sensor, still replace it with a new one and see if that works for you. Sometimes, a dirty sensor might be the problem.
Dissemble the solar light, take out the light sensor, clean it with a damp washcloth, dry it, and reassemble the light again to see if that does the trick.
Ensure there’s no water penetration
You must check your solar light for water damage or humidity. If you think water has penetrated inside and affected your sensor, disassemble the solar light and dry it off, especially the part with the light sensor.
Dry off all other accessories as well, reassemble the light, and take it to a dark room to see if it turns on. If it does, you’ll know water penetration and excess humidity were causing the problem.
Keep blinds/curtains open if placed indoors
If your solar lights are placed indoors or under a shade, they might not be getting an adequate amount of sunlight, causing the light sensor to believe that it is night time.
A solar light placed in the wrong space will end up turning on during the day, giving you less light at night time when you actually need it. Always keep your blinds or curtains open so the sunlight can come in contact with the light sensor and panels and charge the batteries for night time use.
Clean the solar panels
Sometimes, dirt and debris on the solar panels can impact the functioning of your solar light. Using a damp washcloth, thoroughly clean the solar panels.
Please do not use any soaps or chemicals as they can damage the PV cells. If the stains are stubborn and greasy, a solvent that cleans car headlights might do the trick for you. Once cleaned, dry the panels before reassembling and see if your solar lights work correctly.
Replace the batteries
If your sensor does not seem to be the problem, turn your attention to the batteries. A malfunctioning battery can be the reason why your solar lights come on during the day since it can mess with the functionality of the light.
Replace the battery with a new one and see if that solves the problem. If your solar light does not light up at all, your battery has most probably expired, and your solar light needs a new one.
Turn Off and recharge
If your solar lights come on during the day, they might be exhausted. You need to give your solar lights a break so they can recharge and gain back their energy to function appropriately.
If nothing else works, turn off your solar light and remove the battery. Please keep it in the dark, so it does not charge. After 72 hours, reassemble the solar light and see if it still comes on during the day or not.
Get in touch with the manufacturer
When all else fails, and you can’t figure out the problem, you can always call your manufacturer. It is possible that you might have ended up with a faulty piece.
If you have a warranty, the manufacturer might be able to replace your defective solar light with a new one. A manufacturer can also provide replacement parts like light sensors and batteries if they were causing the malfunction.
Final Thoughts
Scientists invented solar lights for the purpose of conserving energy. If your light is malfunctioning, you are just wasting precious energy, and you must solve this problem as soon as possible. The good news is that most ways to fix this problem do not require money!
We hope you now know what to do when your solar lights come on during the day. Leave a comment below if this article helped you fix your problem. Until next time!
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