Winter Solar Street Light Performance Optimization Guide

Why Do Solar Street Lights Perform Poorly in Winter?

It is well known that sufficient sunlight is essential for the efficient operation of solar street lights. However, winter brings a series of challenges. During this season, the duration of sunlight is significantly shortened, and cold weather persists for a long time. Moreover, snowfall and freezing conditions occur frequently.
 

These winter conditions have caused significant obstacles to the normal operation of solar street lights. If proper preparations are not made in advance, your solar street lights are very likely to malfunction during the winter. You might encounter problems such as dim lighting and shortened lighting duration. So, how can we ensure that solar street lights can operate smoothly even in winter?
 

Next, the solar street light manufacturer NOKIN will, based on years of industry experience, address the issue that everyone is concerned about - "How to ensure the normal operation of winter solar street lights", and provide you with actionable optimization solutions. This will allow you to use solar street lights all year round without worries and help practitioners and users enhance the lighting efficiency and operational stability of winter solar street lights.

How to Improve Solar Panel Power Generation in Winter?

The photovoltaic panel is the core energy supply component of solar street lights. To increase the power generation efficiency in winter, the key lies in maximizing the capture of effective sunlight and avoiding the interference of various external factors on light absorption. This is also the basis for subsequent energy storage and stable lighting.

Adjusting Solar Panel Tilt Angle for Winter Sunlight

In winter, the solar altitude angle is much lower than in summer. If the installation angle of the photovoltaic panel continues to use the angle in summer, a large amount of direct sunlight will be missed, directly leading to a significant decline in charging efficiency and difficulty in meeting the energy demand for nighttime lighting.
 

Appropriately increasing the tilt angle of the photovoltaic panel is a key measure to improve the light energy capture in winter. The adjustment of the tilt angle should be flexibly adapted to the local latitude. Generally, it is recommended to increase by 10°-15° from the local latitude, so that the photovoltaic panel can more accurately receive the low-angle sunlight in winter, maximizing the capture of light energy.
 

For regions in the Northern Hemisphere, the orientation of the solar panel is also crucial - it should be as close to south as possible, with an error control within 5°. This orientation allows the solar panel to receive the most sufficient direct sunlight during the winter daylight hours, effectively avoiding power loss caused by orientation deviation. The following table provides recommended installation angles of solar panels for the Northern Hemisphere in winter for reference:
 

Choosing Installation Locations to Avoid Winter Shading

In winter, the solar altitude angle is low, and the shadows formed by trees, buildings, billboards, etc. are longer and wider than in summer. Special attention should be paid to the fact that solar panels have a "hot spot effect", even a slight local shading can lead to a significant decline in overall power generation efficiency. It cannot be ignored.

Choose an unobstructed installation location

When selecting the installation location for solar street lights, the preferred option is an open area without obstructions that receives sufficient sunlight. Avoid areas with tall and lush trees and surrounding tall buildings to ensure that the solar panel is not blocked during the winter daylight hours (usually from 9:00 to 15:00).

Optimize installation location

If the installation location of the solar street lights is truly restricted and cannot avoid the obstruction, then the height or position of the solar panels needs to be adjusted to ensure that the shadow of the obstruction does not cover the surface of the photovoltaic panels. In case of necessity, low-lying obstacles (such as dead branches and small debris) around can be removed.

Removing Snow, Ice, and Dirt From Solar Panels in Time

Snow and ice coverage is one of the direct reasons affecting the light emission efficiency of solar panels in winter. If not cleaned in time, prolonged coverage may even damage the photovoltaic panel components. Therefore, to ensure the normal operation of the solar street lights in winter, cleaning snow and ice and dirt is an important task, even if it is the main focus.
 

Cleaning time: Complete the cleaning within 24 hours after the snowfall stops to prevent the melting and refreezing of the snow from increasing the difficulty of cleaning. Conduct a weekly inspection daily and clean dust, bird droppings and other dirt in time.
 

Cleaning tools: Use soft brushes, soft cloths or low-pressure mode high-pressure water guns for cleaning. Do not use hard scraping tools to avoid scratching the anti-reflective coating and affecting light absorption.
 

Special case: When the photovoltaic panels are heavily frozen, first spray them with water at a temperature not exceeding 40℃ to melt the ice, then wipe them clean with a soft cloth to prevent the glass from cracking due to the high-temperature water.

How to Enhance Battery Performance of Solar Street Lights in Winter?

The battery is the "energy warehouse" of solar street lights. Low temperatures in winter can cause a decline in battery activity, reducing storage capacity and output efficiency. Therefore, optimizing battery performance is a core aspect for ensuring the stability of lighting in winter.

Choosing Batteries Suitable for Low-Temperature Environments

Ordinary batteries will lose 30%-50% of their storage capacity when exposed to temperatures below -10℃, and they are prone to problems such as insufficient charging and inability to discharge. Therefore, when using solar street lights in winter, it is necessary to prioritize the use of low-temperature-resistant battery models. The following table shows common low-temperature-resistant battery types and related parameters for reference:
 

Increasing Battery Capacity for Winter Operation

In addition to selecting low-temperature-resistant batteries, appropriately increasing battery capacity is also an effective measure to deal with reduced solar radiation in winter. It is recommended to increase the battery capacity by 20%-30% during the design stage based on the local winter daylight duration to ensure that the street lights can meet the normal lighting requirements even in continuous cloudy and snowy weather.

Battery Insulation and Thermal Protection Measures

For regions with low winter temperatures (below -10℃), merely selecting low-temperature-resistant batteries is not enough. Additional insulation or heat insulation treatment for batteries is necessary to maintain the working environment temperature, reduce energy loss, and extend battery life. Common battery insulation methods are simple and easy to operate, with low costs. The specific methods are as follows:

Battery box insulation:

Lay insulation material (such as glass wool, polyurethane insulation material) inside the battery box. The thickness of the insulation material is recommended to be 5-10mm, which can effectively reduce the impact of external low temperatures on the battery. The reference cost is 15-30 US dollars per set.

Optimization of installation location:

Install the battery box at the bottom of the street light pole or below the ground (with waterproof treatment), taking advantage of the insulation effect of the soil or the street light pole to reduce temperature fluctuations and their impact on the battery.

Avoid exposing batteries: Do not install batteries exposed outdoors to prevent direct contact with rain and snow, and reduce the direct impact of low-temperature cold winds to prevent the battery temperature from dropping sharply.

How Intelligent Controllers Reduce Energy Consumption in Winter?

The power generation of solar street lights in winter and battery energy storage are limited. Through intelligent control to optimize working modes and reduce ineffective energy consumption to achieve "on-demand lighting" is a key means to improve lighting stability, and it can also reduce maintenance costs.

Time-Based Dimming Strategies for Long Winter Nights

During winter nights, when the temperature is low and the number of pedestrians and vehicles is relatively small, if the entire lighting remains at high brightness, it will consume a lot of electricity, causing the street lights to turn off prematurely. Use segmented brightness control to adjust the lighting brightness according to the number of people and vehicles during the night, balancing lighting needs and energy conservation. Common segmented brightness control schemes:
 

By segmenting control, 30% to 40% of the ineffective energy consumption can be reduced, ensuring that the street lights can still operate normally for 3 to 5 days in winter under continuous snowy weather conditions.

Motion Sensor Lighting for Low-Traffic Winter Areas

For areas with sparse pedestrian and vehicle traffic (such as side roads of residential areas, rural roads, and park paths), the motion sensor automatic dimming function can be enabled to further optimize energy consumption and enhance battery endurance.

The working principle of the motion sensor

When detecting pedestrian or vehicle activities, it automatically switches to high-brightness mode (100% power), remaining in this mode for 30 to 60 seconds; when no activities are detected, it automatically switches to low-brightness mode (20% - 30% power), or even turns off the lighting to achieve "light on when people are present, light off when people leave". Advantages

Compared with segment-based brightness control, motion sensor dimming can save more than 50% of energy consumption and has a lower installation cost (the reference price of an ordinary motion sensor is $20 - $40 per unit). It is suitable for wide-scale promotion and application.

What to Do in Extreme Winter Conditions With Limited Sunlight?

For areas with severe cold conditions and frequent continuous snowy weather, relying solely on basic optimization measures may not be sufficient to ensure the stable operation of solar street lights. The following alternative solutions and advanced optimization ideas can be adopted to further enhance the reliability of the equipment.

Using Reflective or Auxiliary Methods to Increase Solar Gain

If the site is limited and the photovoltaic panel cannot be installed in an unobstructed and optimal position, reflective devices can be used to increase the light capture of the photovoltaic panel without adding additional costs for the photovoltaic panel.

Common reflective strategies:

Install reflective panels (such as aluminum reflective panels or high-reflectivity films) on both sides or below the photovoltaic panel. The angle of the reflective panels should be adjusted to 45° with the photovoltaic panel. This will concentrate the scattered and reflected light onto the surface of the photovoltaic panel, increasing the power generation by 10% - 15%.

Reference cost:

The cost of common reflective panels (each 1m × 0.5m) is $10 - $20, and the cost of reflective films (per square meter) is $5 - $10. They are low in cost and easy to install, suitable for the renovation and upgrade of existing solar street lights.

Backup Power Options for Prolonged Snowy or Cloudy Weather

For areas with extremely severe cold and continuous snowy weather lasting more than 7 days, even with optimized photovoltaic panels and batteries, there may still be insufficient charging and battery depletion. In such cases, a backup power source can be set up to ensure the continuous and stable operation of the street lights. Common backup power source solutions:
 

Winter Maintenance Tips for Solar Street Lights

The maintenance of solar street lights in winter focuses on "prevention in advance, regular inspection, and timely handling". Through scientific maintenance and monitoring, equipment failures can be effectively reduced, equipment lifespan can be extended, and maintenance costs can be lowered.

Regular Inspection of Solar Panels, Batteries, and Controllers

In winter, the inspection frequency should be appropriately increased. It is recommended to inspect once every two weeks, focusing on the following core components:

Photovoltaic panel:

Check if the surface is covered with snow, ice, or dirt, if there are scratches or damages, and if the connection lines are loose or aged;

Battery:

Check if the battery box is sealed properly, if there is water ingress, if the battery voltage is normal (the open-circuit voltage should be between 12.5V - 13.5V), and if there are bulges or leakage;

Controller and lights:

Check if the controller is working normally, if there are fault codes, if the lights are flickering or not lighting up, and if the connection lines are secure.

Winter Maintenance Planning and Snow Removal

Based on the characteristics of winter weather, formulate targeted maintenance plans, focusing on the following points:

Clear snow promptly:

After the snow stops, clear the snow on the photovoltaic panel surface to avoid a long-term cover that leads to a decrease in power generation efficiency or even component damage;

Battery maintenance:

Conduct a balanced charge once a month for the battery to avoid "sulfation" and extend battery life; If the battery voltage is abnormal, replace the battery in time; Fault Handling: In case of equipment failure (such as lights not lighting up, photovoltaic panels not charging), the machine should be stopped for inspection immediately to prevent the failure from escalating. During maintenance in cold weather, anti-freezing measures should be taken to avoid further damage to the equipment.

Remote Monitoring for Large-Scale Solar Street Light Projects

For large-scale solar street lights (such as on main urban roads and rural roads), the remote monitoring system can be enabled to monitor the power generation capacity, battery charge level, and lighting status of each street light in real time. This allows for timely detection of faults and early warnings, reducing the cost of manual inspections.

Key Takeaways for Stable Solar Street Light Operation in Winter

The core of enhancing the performance of solar street lights in winter always revolves around three points: maximizing light absorption, strengthening battery performance, and intelligent energy consumption control. As long as these three points are well implemented, it is possible to effectively cope with challenges such as short winter sunlight, low temperatures, snow and ice, and ensure the lighting efficiency and operational stability of solar street lights.

Implementing these optimization measures not only improves the lighting stability of solar street lights in winter, avoiding the problem of "not charging fully during the day and not lighting up at night", but also significantly extends the equipment's service life (by 2-3 years), reduces long-term maintenance costs, and enables solar street lights to fully demonstrate their advantages of energy conservation, environmental protection, and efficiency in winter.

If you encounter issues related to battery selection, intelligent control, etc. during the optimization process of winter solar street lights, you can contact the professional solar street light manufacturer NOKIN at any time to obtain more professional solutions.