One question we frequently hear is whether our solar lights are affected by weather conditions or shorter daylight hours during winter. The straightforward answer is yes, solar lights can function even on cloudy days or in winter, though their performance might vary. At Solareye, we’ve developed a variety of solar lights, from the Solareye80 ground light, often used to mark cycle paths and pedestrian walkways, to the Solareye Bollard Light, which provides brighter illumination to safely guide people through outdoor spaces at night. All our Solareye products are designed to maximize charging efficiency under Northern European weather conditions and don’t require direct sunlight to operate.

Keep reading 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 or winter days.

How Do Solar Lights Operate?

Solar lights function by transforming sunlight into electrical energy, which is stored in batteries for use during the night. Each solar light comes equipped with a solar panel, commonly referred to as a photovoltaic (PV) panel. This panel absorbs sunlight and converts it into electricity. The efficiency of this conversion depends on the quality and size of the solar panel, along with the intensity of the sunlight.

The electricity generated by the solar panel is stored in a rechargeable battery. This storage capability allows the light to operate during the night or on cloudy days when sunlight isn't available. The battery's capacity determines how long the light can run on stored energy.

A charge controller is essential for safeguarding the battery from overcharging by the solar panel during sunny periods or from excessive discharge during use. It ensures the battery remains durable and efficient.

Solar lights generally use LED (Light Emitting Diode) bulbs because they're energy-efficient, long-lasting, and consume minimal power to produce light. The stored electricity in the battery powers these LEDs.

Most solar lights include an integrated light sensor that automatically switches the light on at dusk and off at dawn. This sensor monitors the surrounding light levels and controls the lighting based on the time of day, conserving the stored energy in the battery for when it's truly needed.

In short, during the day, the solar panel charges the battery. When darkness falls, the light sensor triggers the LED light to turn on, powered by the stored electricity in the battery. This cycle repeats daily, providing a sustainable and eco-friendly lighting solution.

Do Solar Lights Require Direct Sunlight?

On cloudy days or in winter, when daylight hours are shorter and the sun sits lower in the sky, solar panels receive less sunlight, reducing energy production. However, most solar lights are designed to handle these conditions in various ways:

• Efficient Solar Panels: Contemporary solar lights utilize highly efficient photovoltaic cells capable of converting even indirect or diffused sunlight (such as on cloudy days) into electricity, albeit at a lower 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 can influence how long the lights will run. On days with less sunlight, the lights might not charge fully, leading to shorter operational times.
• LED Technology: Solar lights typically employ LED bulbs due to their energy efficiency and longer lifespan. This means they can still provide light even when the battery isn't fully charged.

Have you ever considered cleaning your solar lights? Discover more in our blog post >

How Are Solareye Lights Engineered for Winter or Cloudy Days?

High-Capacity Batteries

Our solar lights are crafted to illuminate throughout the night on the longest winter night (December 21st), keeping Northern European weather conditions in mind. To accomplish this, Solareye80 ground lights, Solareye roof lights, and Solareye Bollard lights are equipped with high-capacity, long-life lithium iron phosphate batteries. These store energy collected during the summer months, when sunlight is abundant, for use in winter when the battery may not receive a full charge due to cloud cover or fewer daylight hours.

Solareye80 ground lights can sustain illumination for 200 hours after a full charge. However, since the built-in light sensor activates the light only when it's dark, it will only ever be lit for a maximum of 16 hours (on the longest night). This leaves plenty of charge remaining, which gets replenished as the battery charges during the day.

Anti-Skid Dimples

Another design element that enhances the Solareye80 ground lights' charging efficiency is the anti-skid dimples. Besides ensuring the surface of the ground lights is safe for bicycle wheels, these dimples also capture more sunlight, boosting charging efficiency.

Motion-Activated Illumination

Several design features help optimize charging for Solareye Bollard Lights. Alongside the high-capacity battery, Solareye Bollard Lights can be set to idle at 50% illumination and increase to 100% when the built-in motion sensor detects a user approaching. By running at 50%, the available charge in the battery is optimized, and full illumination only occurs when necessary (i.e., when someone uses the path).

Learn more about how motion sensors in solar lights work >

Solareye Roof Lights are also programmed to optimize charging by only illuminating when required. The high-capacity battery can provide up to 18 hours of continuous illumination; however, Roof Lights are programmed to switch off every 45 seconds unless motion is detected. This means that from a full charge, Solareye Roof Lights will illuminate over 1,500 times—far more than is necessary for typical portable toilet use.

Learn more about solar lighting for portable toilets >

Other Ways to Enhance Your Solar Lights' Performance

To maximize performance during cloudy days or in winter, it’s crucial to position solar lights in spots where they can receive maximum sunlight throughout the day and make sure the solar panels are clean and unobstructed.

For more information on layouts and spacing of solar lights, check out our Solareye80 ground light spacing guide >

Learn more about how to install Solareye80 ground lights >

Solar Lights from Solareye

For solar lights you can rely on to illuminate even on the longest, cloudiest winter nights, choose Solareye. Our lights are low-maintenance, cost-effective to run, and ideal for off-grid locations as well as gardens and residential settings.

Contact our friendly team to discuss your needs.