Paying Someone to Clean Solar Panels in the GTA

The site's price research found two Canadian sources with a cleaning price, and their ranges overlap. CANBIO, in a 2023 guide that profiles Ontario cleaning services, says the average Ontario price for cleaning ranges from $10 to $20 per panel. It adds that a service might offer a bulk rate for a large array, and that panels that are hard to reach or heavily soiled may cost extra.

ProWashing, a pressure-washing company that cleans panels in Toronto, says solar panel cleaning typically costs $150 to $350 for a standard residential system, with an average of $15 to $25 per panel. It says prices vary with system size, roof access (one storey or two) and location. ProWashing also says many companies charge a minimum fee of $100 to $250, regardless of the number of panels.

That minimum matters most on a small array, where the per-panel sum can come to less than the minimum, so the minimum sets the price. The site's solar panel cleaning cost calculator does the sum for you: it multiplies your panel count across the full spread of the two per-panel figures, from CANBIO's $10 to ProWashing's $25, and treats ProWashing's minimum as a floor rather than an extra charge. Neither source has seen your roof, so treat any range as a starting point and ask for a written price.

Usually not, according to a company that sells maintenance itself. GreenEnerCanada says rain typically washes away most dirt and debris, "making professional cleaning an unnecessary expense in most cases". It credits the Sierra Club for that advice.

Green Building Canada takes a firmer line in its guide to what solar panels cost in Canada. It says "regular cleaning and inspections are required to maintain the performance of your PVs", meaning photovoltaic panels. It adds that, depending on how often it rains, "a cleaning schedule could be up to twice annually, with warmer and drier regions requiring more". It sets no minimum number of cleans.

The two sources that publish cleaning prices go further and treat a yearly clean as the norm. ProWashing, which sells cleaning, says solar panels "typically require cleaning once or twice a year to maintain peak efficiency", and CANBIO's guide, which profiles cleaning companies, calls cleaning at least once or twice a year in Ontario advisable as a general rule.

Your own output figures are a better guide for your roof than any of these sources: if output on clear days holds up against the same month last year, rain is probably doing the job.

When one of GreenEnerCanada's exceptions fits your roof, or when your output drops and you can see the dirt. The exceptions, all from GreenEnerCanada's service page:

• Low tilt. GreenEnerCanada says panels installed at less than a 5-degree angle may not self-clean effectively with rain.
• Dusty sites. Panels near highways, factories or agricultural fields can accumulate dust that may require cleaning.
• Bird droppings. Heavy droppings can block enough sunlight to affect energy production.

The fourth reason is your own data. GreenEnerCanada's list of reasons to call for service includes visible dirt or debris that does not wash off, and performance drops in a monitoring app. If output falls on clear days against the same month last year and you can see grime from the ground, a clean is a sensible first step. If output falls and the panels look clean, look for another cause: the guide to signs your array is producing less than it should shows how to read the figures.

Only the parts you can reach safely from the ground. GreenEnerCanada says that if cleaning is needed, avoid "high-pressure water or abrasive materials, which can damage the panels". It adds: "Always check with your installer for proper cleaning guidance." CANBIO suggests soft, non-abrasive materials and no harsh chemicals, and says to "never spray cold water onto hot panels to prevent cracking".

Stay off a pitched roof. The Canadian Centre for Occupational Health and Safety (CCOHS) writes for roofing workers, and its list of hazards in residential roofing starts with falls: unprotected edges, improper ladder use, and slippery or sloped surfaces. It also says maintenance on flat roofs tends to carry a lower level of risk to workers than maintenance on sloped roofs. Wet glass on a pitched roof is both slippery and sloped.

The same CCOHS page raises two more risks that apply to panel cleaning. Among biological hazards it lists "Animal and bird droppings, including hantavirus and psittacosis", two infections the page links to droppings. That makes heavy droppings, one of the exceptions above, a poor job to tackle yourself. It also passes on the Electrical Safety Authority's recommendation to keep 3 metres away from powerlines, worth knowing before you raise a long pole near an overhead line.

No company in this index is listed as a cleaner. None of its 161 companies carries a cleaning or washing label on its Google record, and the site has no cleaning category. The site removed three businesses by hand as outside the solar trade: Skypole Window Cleaning and Bronto Clean, both labelled window cleaning services on Google, and ProWashing, labelled a pressure washing service.

That leaves three routes: the company that installed your system, a solar service company, or a cleaning company. Start with the installer, which knows what is on your roof. The index lists 4 companies in its repair and maintenance category; ask any of them whether cleaning is part of a service visit or a separate charge.

Green Building Canada says professional maintenance services can cost $150 to $400 a year, in a passage that opens with regular cleaning and inspections. Ask any company quoting a maintenance plan whether a clean is included. The site's guide to what solar maintenance involves in Ontario covers the rest of the yearly upkeep.

How it prices the job, how it will reach and wash the panels, and whether it is insured. Six questions cover it:

1. Do you charge per panel, per visit, or a minimum fee?
2. How will you reach the panels, and will anyone walk on the roof?
3. What water, pressure and brushes will you use on the glass?
4. Will the work affect my panel or installer warranty?
5. Do you carry liability insurance and WSIB (Workplace Safety and Insurance Board) coverage?
6. Will you tell me about any cracks, chewed wiring or nests you see?

Check the answers yourself: SolarPanelFinder does not check licences, insurance or WSIB coverage for any company, as its methodology says.