Monitoring, maintenance and repair

Solar is low-maintenance rather than no-maintenance, and the failure mode is quiet. A panel that has stopped producing does not make a noise or leak anything. Unless somebody is watching the numbers, an array can lose a fifth of its output for a year before anyone notices.

Step one: know what the array is supposed to produce. Ask your installer for the modelled annual figure in kilowatt hours and the month-by-month breakdown, and keep it. Without that baseline you cannot tell a bad year from a broken array. Ottawa has good sun by Canadian standards, with the Canada Energy Regulator placing the city at 6.09 kilowatt hours per square metre, ahead of Toronto and every other major city east of the prairies (Canada Energy Regulator, Which cities have the highest solar potential in Canada), and Natural Resources Canada publishes a mapping application that estimates photovoltaic potential in kilowatt hours per kilowatt peak anywhere in Canada on a roughly 2 kilometre grid, using a 0.75 performance ratio (Natural Resources Canada, photovoltaic potential maps). Use one of those as a sanity check on whatever number an installer gives you.

Step two: monitoring. Most modern inverters and microinverter systems report production to an app or portal, and per-panel monitoring is worth paying for because it identifies which module has failed rather than telling you the total is down. Set an alert. Then actually look at it once a month in the first year, which is when installation faults show up.

Step three: cleaning, or not. In this climate rain and snowmelt do most of the cleaning and the annual gain from washing panels is usually small. Two Ottawa exceptions are worth knowing. Spring pollen combined with a dry May can leave a real film, and properties near arterial roads or construction accumulate grit. Never send someone onto an icy roof to clear snow off an array. The production you recover in February is worth far less than the fall, and the panels will clear themselves.

Step four: the inspection. A visual check every two to three years covers the things that degrade: the condition of the roof penetrations and their flashing, the racking fasteners, cable management where UV and ice have been working on the wiring, the condition of any conduit, and the inverter's error log. Freeze-thaw cycling loosens things here in a way it does not in milder climates.

The inverter, which is the part that fails. String inverters typically carry ten to twelve year warranties and commonly need replacing somewhere between year ten and year fifteen, against panels warranted for twenty-five. Microinverters carry longer warranties, often twenty to twenty-five years, but there is one per panel and replacing a failed unit means going back on the roof. Budget for an inverter replacement as a known future cost rather than a surprise: indicatively $2,500 to $5,000 for a string inverter on a residential array, and $300 to $600 per microinverter including the roof work.

What it costs in Ottawa in 2026. Indicative. A monitoring review and visual inspection is commonly $200 to $450. Panel cleaning, where it is genuinely warranted, $250 to $600 for a residential array. Diagnosing and replacing a single failed microinverter, $400 to $800 including labour. A string inverter replacement, $2,500 to $5,000. Squirrel-proofing the array perimeter with critter guard, $600 to $1,500 depending on the array size.

What makes an Ottawa array different. Wildlife, more than people expect. Grey squirrels nest in the warm cavity under a rooftop array and chew the DC wiring, and Ottawa has a great deal of grey squirrel. Critter guard around the array perimeter is cheap at installation and awkward afterwards. The second local factor is ice: meltwater refreezing at the lower edge of an array can build a substantial slab, which stresses the racking and the gutters below it. The third is the snow-clearing temptation, which damages more arrays in this city than hail ever has.

Who should do the work. Anything touching the electrical side is work for a Licensed Electrical Contractor, and a notification of work must be filed with the Electrical Safety Authority before that work begins (Electrical Safety Authority, Notifications and inspections). Remember that panels are live in daylight regardless of what is switched off: Ontario's alert on photovoltaic systems notes that small amounts of sunlight can produce a voltage potential capable of causing electrocution or arc-flash injury (Ontario, Alert: photovoltaic systems). Cleaning and visual inspection are not electrical work, but they happen at height, so insist on fall protection.

What to ask before you hire. Do you have the original commissioning data and the modelled production for this array. Is the monitoring per-panel or whole-system. What is still under warranty, on which component, and who administers that warranty now. If the original installer is out of business, will you take on the system. Are you a Licensed Electrical Contractor. Will you file the ESA notification for any electrical work. What do you charge for a callout versus an annual arrangement.

One structural warning. A good number of solar companies that installed in Ontario during the earlier incentive era no longer exist, which leaves a lot of arrays with warranties nobody is administering. Before you buy, ask how long the company has traded under its current legal name and who would honour the workmanship warranty if it stopped. A twenty-five year promise from a three-year-old company is worth what it is worth.