Solar Panel Cleaning Yield Recovery
# Solar Panel Cleaning Yield Recovery: Soiling Loss, Water-Fed Pole Engineering, and Cleaning ROI for Photovoltaic Systems in Canada
Photovoltaic system owners lose measurable energy to soiling — the accumulation of dust, pollen, bird debris, road salt, soot, and industrial particulate on module cover glass. Annual soiling losses range from under one percent in wet temperate climates with frequent rain reset, to more than ten percent in arid climates where rain does not reliably clean panels. The cleaning decision is a trade-off: frequent cleaning is expensive and, below a soiling threshold, can be net-negative relative to accepting the loss.
## The framework
The reference calculator takes eight inputs — nameplate capacity, regional irradiance, days since last cleaning, soil class, electricity price, cleaning visit cost, tap water TDS, and panel height — and returns the current loss percentage, daily dollar loss, optimal cleaning interval, annual recovered yield, and recommended water-fed pole (WFP) hardware. All outputs are ranges, not point estimates.
## Water-fed pole engineering
WFP cleaning delivers deionized pure water through a reach pole to a soft brush, allowing the operator to clean from grade without rooftop access. WFP is the preferred mechanism for small and medium PV arrays because:
- Pure water (≤ 10 ppm outlet TDS) dries without leaving residue, producing spot-free drying without towelling
- Soft boar's-hair or synthetic brushes are scratch-free and warranty-compliant
- Operation from grade eliminates OSHA 29 CFR 1926 Subpart M and Ontario O. Reg. 213/91 s. 26 fall protection triggers
- Practical reach extends to approximately 45 feet, covering most residential and small commercial arrays
## Datasets
Seven open datasets under CC BY 4.0:
- `soiling_loss_rates.csv` — 660 rows covering climate zone × tilt × soil class × days
- `tds_resin_capacity.csv` — mixed-bed DI cartridge capacity as a function of inlet TDS
- `pv_geometry_reach.csv` — installation archetypes to pole length reach
- `regional_irradiance_ontario.csv` — monthly kWh/m²/day for six Ontario cities
- `cleaning_frequency_roi.csv` — annual yield recovered by interval for residential/commercial/utility classes
- `tap_water_tds_profiles.csv` — municipal TDS for 28 Canadian cities
- `regulation_crosswalk.csv` — OSHA, CSA, IEC, ASTM, Health Canada, NRCan, ECCC
## Engines
Eight language implementations (Python, Rust, Java, Ruby, Elixir, PHP, Go, and a Nostr long-form bridge) compute identical results for the canonical test vector.
## Counter-intuitive finding
For most small-to-medium PV in wet-temperate Canadian climates — including Southern and Northern Ontario — routine paid cleaning is net-negative on pure ROI terms. Rain-reset alone dominates any paid schedule for these systems. Cleaning becomes economical in arid climates, with high soiling rates, or when piggybacked on an existing service call (for example, a commercial building's regular WFP window cleaning).
Reference model only. Not professional engineering advice.
Working paper: https://www.binx.ca/guides/solar-panel-cleaning-yield-recovery-guide.pdf
Repository: https://github.com/DaveCookVectorLabs/solar_panel_yield_2026
