We frequently get asked if our solar lights are affected by weather conditions or shorter daylight hours during the winter. The short answer is yes—solar lights can function even when it's overcast or during the colder months, but their performance might be somewhat diminished. At Solareye, we’ve developed a variety of solar lights, including the popular Solareye80 ground light, commonly used to mark cycle paths and pedestrian walkways. We also offer the Solareye Bollard Light, which provides enhanced illumination to guide people safely through outdoor spaces at night. All Solareye products are designed to maximize charging efficiency under Northern European weather conditions, and they don't require direct sunlight to operate effectively.

Read on to learn more about how solar lights function, how reduced sunlight impacts charging, and how we've engineered our solar lights to perform optimally even on cloudy days or during the winter.

How Do Solar Lights Work?

Solar lights operate by transforming sunlight into electrical energy, which is stored in batteries for use after dark. Each solar light includes a solar panel, also referred to as a photovoltaic (PV) panel. This panel captures sunlight and converts it into electricity. The efficiency of this conversion depends on factors such as the quality and size of the solar panel, as well as the intensity of the sunlight.

The electricity produced by the solar panel is stored in a rechargeable battery. This storage capability allows the light to remain operational during the night or on cloudy days when sunlight isn't available. The capacity of the battery determines how long the light can continue operating on stored energy.

A charge controller is essential for safeguarding the battery from overcharging during bright days or from excessive discharge during operation. It ensures both the longevity and efficiency of the battery.

Solar lights usually incorporate LED (light-emitting diode) bulbs because they are energy-efficient, durable, and consume minimal power to produce light. The stored energy in the battery powers these LEDs.

Most solar lights include an inbuilt light sensor that automatically switches the light on at dusk and off at dawn. This sensor monitors the surrounding light levels and adjusts the lighting accordingly, conserving the stored energy in the battery for when it’s most needed.

In summary, during the day, the solar panel charges the battery. Once it gets dark, the light sensor triggers the LED light to turn on, powered by the stored electricity in the battery. This cycle continues daily, offering a sustainable and eco-friendly lighting solution.

Do Solar Lights Require Direct Sunlight?

On overcast days or in winter, when daylight hours are shorter and the sun is lower in the sky, solar panels receive less sunlight, leading to decreased energy generation. However, modern solar lights are designed to handle these situations in several ways:

• Efficient Solar Panels: Contemporary solar lights utilize highly efficient photovoltaic cells that can convert even indirect or scattered sunlight (such as on cloudy days) into electricity, though at a reduced rate compared to direct sunlight.
• Energy Storage: Solar lights store energy in batteries during the day, enabling them to function at night. The battery's capacity influences how long the lights will stay lit. On days with limited sunlight, the lights may not charge fully, resulting in shorter periods of illumination.
• LED Technology: Solar lights generally use LED bulbs due to their energy efficiency and long life span. This means they can still provide light even when the battery isn’t fully charged.

Curious about whether you should clean your solar lights? Check out our blog post for tips!

How Are Solareye Lights Designed for Optimal Charging in Winter or on Cloudy Days?

High-Capacity Batteries

Our solar lights are built to shine throughout the night on the longest winter night (December 21st), keeping Northern European weather conditions in mind. For example, Solareye80 ground lights, Solareye roof lights, and Solareye Bollard lights all feature high-capacity long-life lithium iron phosphate batteries to store energy collected during the summer months when sunlight is abundant. These batteries ensure that lights can operate effectively in winter, even when the battery isn’t fully charged due to cloud cover or fewer daylight hours.

Solareye80 ground lights can illuminate for up to 200 hours on a single full charge. Since the inbuilt light sensor only activates the light when it’s dark, it will only be illuminated for a maximum of 16 hours (on the longest night). This leaves plenty of reserve charge that gets replenished during the day.

Anti-Skid Dimples

Another design element that enhances the Solareye80 ground lights’ charging efficiency is the anti-skid dimples. Besides providing a safe surface for bicycle wheels, these dimples also catch more sunlight, improving overall charging performance.

Motion-Activated Illumination

Solareye Bollard Lights are equipped with several features to optimize charging. Alongside the high-capacity battery, the bollard lights can be set to idle at 50% illumination and boost to 100% when the built-in motion sensor detects someone approaching. By running at half brightness, the available charge in the battery is conserved until it’s truly needed (i.e., when someone uses the path).

Learn more about how motion sensors work in solar lights here.

Solareye Roof Lights are also designed to optimize charging by only turning on when necessary. The high-capacity battery can provide up to 18 consecutive hours of illumination, yet the roof light is programmed to switch off every 45 seconds unless motion is detected. This means that from a full charge, Solareye Roof Lights can illuminate more than 1,500 times—far more than what’s needed for typical portable toilet installations.

Learn more about solar lighting for portable toilets here.

Other Ways to Boost Your Solar Lights' Performance

To enhance performance during cloudy days or in winter, it’s important to place solar lights in areas that receive maximum sunlight throughout the day and make sure the solar panels are kept clean and free of obstructions.

For more details on solar light layouts and spacing, check out our Solareye80 ground light spacing guide.

Learn more about installing Solareye80 ground lights here.

Solar Lights from Solareye

For solar lights you can rely on to keep your pathways lit even on the darkest, cloudiest winter nights, choose Solareye. Our lights are low-maintenance, cost-effective to run, and ideal for off-grid locations as well as residential and garden settings.

Contact our friendly team today to discuss your lighting needs.