Low temperatures and icy and snowy weather in winter are the "invisible killers" of road safety. Data shows that the road accident rate in northern regions during winter is 40% higher than in other seasons. The core reasons are low visibility, a decrease in the friction coefficient of the road surface, and increased difficulty for drivers to judge road boundaries and curves.
Solar-powered road studs, as active road warning devices, can emit light through solar charging without an external power supply, providing clear road outline guidance for vehicles at night and in rainy or snowy days. However, many road construction and maintenance parties have doubts: Will low temperatures and ice and snow cause solar-powered road studs to "go on strike"?
The battery life of solar-powered road studs relies on the energy storage of the built-in battery, and low temperatures will directly damage the working environment of the battery. When the temperature drops below -10 ℃, the activity of the internal electrolyte in ordinary lithium batteries will significantly decrease, resulting in a decline in charging acceptance capacity and a "shrinkage" in discharge capacity. Data shows that at -20℃, the actual capacity of ordinary lithium batteries is only 50% of that at normal temperature. Road studs that could originally support 12 hours of night lighting may be shortened to less than 6 hours. It cannot cover the road warning needs for the entire night.
More importantly, low temperatures can also cause "irreversible damage" to batteries: If batteries operate at temperatures below -30 ℃ for a long time, crystallization will occur on the internal electrodes, directly reducing battery life and even causing faults such as leakage and bulging.
The two major characteristics of winter - short daylight hours and weak sunlight intensity - will directly cut off the "energy source" of solar road studs. Take Northeast China as an example. The average daily sunshine duration in December is only 6 to 7 hours, which is nearly half shorter than that in summer. Meanwhile, in winter, the slanting Angle of sunlight is large, and the intensity of ultraviolet rays is only 60% of that in summer. The photoelectric conversion rate of ordinary solar panels will drop from 18% to below 12%.
This means that ordinary solar-powered road studs may not be fully charged in winter - the energy absorbed during the day is insufficient to support the light emission at night. Over time, this can lead to battery depletion and eventually stop working.
Snowfall and freezing rain can cover the panels of solar-powered road studs with ice and snow, forming a "physical barrier" : on the one hand, the accumulated snow can completely block sunlight, causing charging to be interrupted; On the other hand, when ice and snow melt and freeze into ice shells, they are not only difficult to clean up but also refract sunlight, further reducing the charging efficiency.
If not cleared in time, the road studs will rely on the remaining battery power to work. When the power is exhausted, the road studs will lose their luminous warning function. On icy and snowy roads, this is equivalent to losing the "road boundary marker", which is very likely to cause vehicles to deviate from the lane.
Low temperatures can cause some road stud materials to enter the "brittle zone". The outer shell of ordinary solar road studs is mostly made of ABS plastic. When the temperature is below -20 ℃, the impact strength of the material will drop by 70%. Once it is crushed by vehicles or hit by snowplows, the outer shell is very likely to crack. According to statistics from relevant departments, the damage rate of ordinary road studs in winter is three times higher than that in summer, and 80% of the damage is caused by collisions during the operation of snowplows.
Material embrittlement not only leads to the scrapping of road studs but also may expose internal batteries and circuits to ice and snow, causing short-circuit faults and increasing maintenance costs and safety hazards.
To address the pain points in winter, professional manufacturers will design cold-resistant solar road studs from three major dimensions: energy storage, structural protection, and charging efficiency. The following are the five core specialized designs, which are also the key references for selection in cold regions:
|
Comparison Dimension |
Ordinary Solar Road Studs |
Cold-Weather Solar Road Studs |
Core Advantage |
|
Battery Types |
Ordinary lithium battery (temperature resistance -10℃ to +50℃) |
Lithium thionyl chloride battery (temperature resistance -40℃ to +60℃). At -20℃, capacity remains above 85% without irreversible damage |
Reliable performance in extreme cold |
|
Shell Material |
ABS plastic (impact strength 30kN) |
Aluminum alloy + reinforced PC (impact strength 100kN). Withstands snowplow pressure, not brittle at -30℃ |
Higher strength and cold resistance |
|
Battery Compartment Insulation |
No insulation |
PU foam insulation layer (5mm thick). Internal temperature 5–8℃ higher than outside, stabilizing battery environment |
Extended battery lifespan in cold climates |
|
Anti-Snow Panel Design |
Flat panel (snow accumulation likely) |
Arc-shaped panel (snow slides off automatically). Snow residue reduced by 90%, no frequent cleaning needed |
Low maintenance, reliable visibility |
|
Solar Panel Type |
Polycrystalline silicon (conversion rate 16%–18%) |
Monocrystalline high-efficiency panel (conversion rate 22%–24%). Conversion rate +30% in weak light, faster winter charging |
Better energy efficiency in low sunlight |
The core of the cold-weather road studs lies in the "low-temperature resistant battery". The currently mainstream lithium thionyl chloride batteries have 2 major advantages: a wide temperature adaptability range and a low self-discharge rate.
The shell serves as the "first line of defense" for solar-powered road studs. Cold-specific road studs will adopt a composite structure of "aluminum alloy + reinforced PC".
The insulation design of the battery compartment directly affects the battery performance. Solar road studs in cold regions will have a 5mm thick PU foam insulation layer installed on the inner wall of the battery compartment. The thermal conductivity of this material is only 0.03W/(m · K), which can effectively block the low temperature from the outside.
When the external temperature is -30 ℃, the internal temperature of the battery compartment can be maintained at -22 ℃ to -25℃ to prevent the battery from entering the "embrittlement zone".
When charging, the trace amount of heat generated by the solar panels will be retained by the insulation layer, further increasing the internal temperature and making the battery charge and discharge efficiency higher.
To address the issue of insufficient charging in winter, solar road studs in cold regions have been optimized from two aspects: "reducing obstruction" and "improving conversion".
Choosing the right product is just the first step. Only through correct installation and maintenance can the cold-resistant solar road studs achieve their maximum value in winter. The following is a practical operation guide for cold regions
|
Selection Criterion |
Correct Requirement |
Common Misunderstanding / Mistake |
Reminder |
|
Battery Temperature Resistance |
Minimum resistance ≤ -30℃; recommended to use lithium thionyl chloride batteries |
Choosing ordinary lithium batteries with nominal resistance of -20℃ |
May fail in extremely cold regions |
|
Casing Impact Strength |
≥ 80kN; should withstand snowplow impact |
Selecting pure plastic casings |
Plastic is prone to cracking in winter |
|
Solar Panel Conversion Rate |
Monocrystalline silicon panels ≥ 22%; weak light performance prioritized |
Blindly pursuing “high power” |
High conversion efficiency in low light is more critical |
|
Panel Anti-Snow Design |
Use arc-shaped panels with snow-sliding design or flat panels with self-melting snow |
Assuming they don’t require cleaning |
In heavy snow areas, frequent cleaning is still necessary |
In winter, the charging time is short. When installing, details need to be optimized to allow the solar-powered road studs to "get more sunlight".
|
Road Type / Condition |
Special Installation Requirement |
Purpose / Advantage |
|
Expressways / Rapid Roads (bends and slopes) |
Installation spacing reduced to 1.5 m |
Enhances visibility and driving safety in critical sections |
|
Main Urban Roads (within 50 m before stop line at intersections) |
Installation spacing densified to 2 m |
Improves warning effect and driver response time |
|
Rural Roads (near houses and trees) |
Installation height increased |
Prevents obstruction from buildings or vegetation |
Check Time:Once a week (on sunny days)
|
Check Content |
Abnormal Handling Method |
|
Inspect outer shell for cracks, deformations, or damages |
Replace the road studs immediately to prevent water intrusion |
|
Check if the light is uniform (night inspection). For insufficient brightness, test battery voltage |
Replace battery if voltage is lower than 3.2V |
|
Inspect solar panel for scratches or stains |
Replace panels with severe scratches to maintain light transmittance |
Cold weather won't cause solar-powered road studs to "go on strike". The key lies in "choosing the right product and using it correctly". Through special optimizations such as heat-resistant batteries, high-strength shells, and insulation designs, the cold-specific solar road studs can work reliably in extremely cold environments of -40 ℃. Meanwhile, through scientific installation and maintenance, the winter failure rate can be reduced by more than 80%.
