A soiling sensor that quantifies PV plant dirt losses at the maximum power point — not just short-circuit current — capturing both non-uniform soiling and angular incidence effects that Isc-based methods miss. Per IEC 61724-1, with sub-minute sampling and an online platform for daily, weekly, and annual soiling pattern analysis.
The Entec Solar E-Dust is a permanent soiling monitoring sensor designed for operating PV plants. Its defining distinction from conventional soiling sensors is the measurement method: where traditional approaches measure soiling loss via short-circuit current (Isc) alone, the E-Dust measures it at the maximum power point (Pmax) by comparing the output of a clean reference module against a soiled (unattended) reference module of the same type.
This Pmax-based approach captures two sources of soiling loss that Isc-based methods miss. The first is non-uniform soiling across the module face — where dust accumulates unevenly, some cells are more affected than others, leading to mismatch effects and bypass diode activation that reduce power output proportionally more than Isc. The second is angular incidence effects — soiling loss varies with the angle of the sun throughout the day, and Isc-based sensors measured at a fixed time miss this variation entirely. The E-Dust's sub-minute sampling captures these angular effects continuously, enabling accurate calculation of soiling-adjusted energy yield.
All data is processed automatically by the Entec online platform and presented with daily, weekly, and annual soiling pattern analysis. This output directly informs the timing and prioritisation of cleaning campaigns — identifying whether cleaning should happen now or whether expected rainfall or low irradiance makes it more economical to wait. The system operates per IEC 61724-1 for soiling loss quantification.
Why Pmax measurement matters for soiling: A module with heavy soiling concentrated on its lower rows of cells may show only a modest Isc reduction — the current is still produced by the upper rows — but the bypass diodes on the lower sub-strings activate, causing a disproportionate power loss. Isc-based soiling sensors would underestimate this loss. Pmax-based measurement via the E-Dust captures it correctly because Pmax reflects the module's actual operating output, including all mismatch and bypass diode effects.
Key Capabilities
Pmax-Based Soiling Loss
Compares maximum power between a clean and a soiled reference module — capturing non-uniform soiling, mismatch effects, and bypass diode activation that short-circuit current methods cannot detect. Provides a more accurate representation of actual energy yield impact than Isc-only methods.
Sub-Minute Sampling
Sampling periods as short as one minute capture soiling loss variation with the sun's angle of incidence throughout the day — a dynamic that fixed-time Isc measurements miss entirely. Essential for accurately quantifying soiling loss in climates where morning dew, angular effects, or variable particle types create time-of-day variation.
Online Platform & Auto Analysis
All data is automatically processed by the Entec online platform. Daily, weekly, and annual soiling pattern reports are generated without manual data export. The platform identifies seasonal soiling patterns, enabling strategic planning for cleaning campaigns and accurate O&M cost modelling.
IEC 61724-1 Compliant
Soiling loss quantification per IEC 61724-1, the standard for PV system performance monitoring. This allows E-Dust soiling loss data to feed directly into bifacial and standard performance ratio calculations, enabling contractually defensible soiling-adjusted PR reporting for PPA and EPC documentation.
Three Variants for Different Deployments
E-Dust: full system with communications and data processing. E-Dust-st: standalone variant for sites without SCADA integration. E-Dust-ss: sensor-only variant for integration into existing monitoring infrastructure. All variants use the same Pmax-based measurement principle.
Cleaning Campaign Optimisation
The E-Dust output directly drives cleaning decisions: how much yield is being lost today, how quickly is soiling accumulating, and whether the cost of cleaning now outweighs the additional yield loss from waiting. The annual pattern analysis identifies high-soiling seasons for proactive scheduling.
Specifications
Measurement MethodPmax comparison — clean vs. soiled reference module
Have you deployed the Entec Solar E-Dust? We'd like to hear how it performed — accuracy compared to Isc-based sensors, platform usability, and whether the Pmax method changed your cleaning decision-making. Use the Get in Touch form on our home page to share your experience.
