How Snow Sensors Work in Solar Tracker Systems
Snow sensors in solar tracker systems are designed to detect snow accumulation on or near photovoltaic (PV) panels and enable the tracker to respond appropriately to protect the system and optimize energy production.
Principle of Operation
- Dual Irradiance Sensor Setup
A common advanced method, exemplified by SEVEN’s Snow Sensor, uses two irradiance sensors:- A snow-exposed sensor that simulates the conditions on the solar panels and is exposed to environmental snow buildup.
- A heated clean sensor inside the sensor housing that continuously melts any snow to maintain a clean measuring surface.
- Comparison of Irradiance Values
The system compares the irradiance measurements from the two sensors to determine the impact of snow coverage. If snow covers the exposed sensor, its irradiance reading drops relative to the clean sensor. This ratio is called the Snow Ratio, which quantifies snow coverage and correlates with energy loss in the PV system. - Communication & Control Signal
The snow sensor communicates snow rate data to the solar tracker control center. When the snow coverage reaches a user-defined threshold, the tracker is commanded to move the solar panels to a position that:- Minimizes mechanical load and risk from accumulated snow.
- Helps shed the snow more effectively by adjusting tilt angles.
By doing so, the system avoids unnecessary movement during low or no snow conditions, while protecting the structure and optimizing energy capture during snowy periods.
Additional Snow Measurement Techniques
- Some systems utilize laser pulse-based snow depth sensors placed at fixed angles (around 20º) to measure the snow depth by detecting distance changes between the sensor and ground or panels. This method can also inform the tracker control strategy to handle heavy snow loads safely.
Benefits of Snow Sensors in Solar Trackers
- Structural Protection: Prevents the tracker from moving into positions under excessive snow loads, which could damage mechanical components.
- Energy Optimization: By identifying when snow is significantly blocking solar irradiation, the system can adjust to improve snow shedding or reduce energy loss due to snow cover.
- Real-time Monitoring: Provides accurate, real-time snow coverage data to operators for better decision-making regarding maintenance and system operation.
Summary of Process
| Step | Description |
|---|---|
| Snow and clean sensors | Measure irradiance levels; clean sensor is heated to avoid snow coverage |
| Data Comparison | Snow ratio calculated by comparing snow-covered sensor and clean sensor irradiance values |
| Control Decision | Threshold snow ratio triggers tracker movement to safe, snow-shedding position |
| Communication | Sensor transmits snow load and energy loss data to control system for ongoing adjustments |
This technology enables solar tracker systems to maintain operational efficiency and structural integrity during snowy conditions, especially in regions susceptible to snow accumulation.
Original article by NenPower, If reposted, please credit the source: https://nenpower.com/blog/how-do-snow-sensors-work-in-solar-tracker-systems/
