Description
3S-SMS – Automatic Soiling Sensor for PV Plants
The SEVEN 3S-SMS sensor measures energy production losses caused by soiling (dust, dirt, and other environmental deposits) on photovoltaic panels. Ideal for commercial, utility-scale, industrial, and rooftop PV installations, the sensor quantifies soiling as a percentage of energy loss, enabling data-driven maintenance and cleaning decisions.
How It Works:
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Two reference cells: one kept clean automatically, the other exposed to natural soiling.
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Compares irradiance values between clean and dirty sensors.
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Calculates the soiling ratio (%) representing the PV system’s energy loss.
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Transmits data via RS485 Modbus RTU to SCADA, PLC, or datalogger systems.
Key Benefits:
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Real-time performance insight: Know exactly how much energy is lost.
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Automatic cleaning system: Keeps one reference cell clean with minimal manual intervention.
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Low water consumption: Only ~36 liters per year (two refills).
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Climate-ready: Operates in hot, humid, or cold conditions (antifreeze option).
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Durable: IP54 housing standard (IP65 optional), built for outdoor environments.
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Seamless integration: Connects to Modbus RTU-based monitoring systems.
Technical Specifications:
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Soiling Ratio: 0–100% | Resolution: 0.1 | Uncertainty: ≤1%
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Output Rate: 1 measurement per second via RS485 Modbus RTU
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Operating Temperature Range: -20°C to +85°C | Humidity: 0–100% RH
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Power Supply: Models available for 100–240 V AC or 24 V DC, 5 A
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Water Tank Capacity: 18 L or 40 L, with a standard hose length of 5 m (customizable up to 20 m)
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Water Consumption: Approximately 100 mL per cleaning cycle
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IP Rating: IP54 (optional IP65)
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Weight: 10.5 kg
Available Models and Features:
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3S-SMS-MB: Communicates via RS485 Modbus RTU, powered by 100–240 V AC, without gateway option.
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3S-SMS-GW: Communicates via RS485 Modbus RTU, powered by 100–240 V AC, includes gateway for cloud-based monitoring.
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3S-SMS-MB-24V: Communicates via RS485 Modbus RTU, powered by 24 V DC, 5 A, without gateway.
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3S-SMS-GW-24V: Communicates via RS485 Modbus RTU, powered by 24 V DC, 5 A, includes gateway for cloud-based monitoring.
Why Monitor Soiling?
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Soiling can reduce annual energy yield by 2–5% in moderate climates or 10–15% in deserts and industrial areas.
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Helps prevent over-cleaning (wasting water and money) or under-cleaning (losing energy production).
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Enables operators to make data-driven decisions for maximum efficiency.
Maintenance & Operation:
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Cleaning typically occurs once per day (adjustable via GUI, up to 3 times per day).
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Water tanks require refilling every 6–12 months depending on size.
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The system can store up to one year of historical soiling data.
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Operates reliably in cold climates using a water-antifreeze mixture.
Standards & Warranty:
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Fully compliant with IEC 61724-1 (Annex C) for soiling measurement.
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2-year warranty covering defects in materials and workmanship.
Applications:
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PV plant performance monitoring
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Rooftop, utility, and industrial solar installations
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Integration with SCADA, PLC, or cloud monitoring systems
