How a crew installs solar panels, from racking to switch-on

What happens before the crew arrives?

The paperwork comes first. The installer finishes the design, applies for the building and electrical permits, and starts the utility connection application where one is required. Materials are ordered and scheduled. You may be asked to clear access to the roof and electrical panel, and to move vehicles. Nothing goes on the roof until the permit is in hand. For how this wider process fits together, including quotes and contracts, see the solar panel installation process in Canada, and solar panel permits in Alberta for a regional example.

How are the racking and panels fitted?

1. Safety setup. The crew sets ladders, fall protection and a work area.
2. Layout. They mark rafter positions and panel rows on the roof, following the approved design.
3. Roof attachments. Mounts are fixed into the structure, not just the roof deck, and sealed and flashed to keep water out.
4. Rails. Racking rails clip onto the mounts, levelled and aligned.
5. Panels. Panels are lifted, set on the rails, clamped and bonded for grounding.

Good flashing is the part to watch, since roof leaks are the most expensive mistake. Ask how penetrations are sealed and who warrants the roof work. Panel orientation and tilt follow the design, and the best panel direction explains the thinking behind it.

How is the system wired and connected?

Wiring links the panels in strings, runs in conduit to the inverter, and then through a disconnect to your main electrical panel. A licensed electrician or a qualified crew member makes the final connection, and the work must meet the electrical code and any rapid-shutdown rules in force where you live. Labels go on the equipment so that firefighters and utility crews can identify it.

The inverter may sit in the garage, a basement or outside on a wall, depending on its type. See solar inverter types for the options. Monitoring gear is also set up, and what to track in solar monitoring tells you what to check afterwards.

What happens after the panels are up?

The crew tests the system, but it usually stays switched off until approvals are complete. An electrical inspector checks the work, and the utility may need to inspect, replace or reprogram your meter before you may operate the system. Only after that do you get permission to turn it on. The gap between finished installation and permission to operate can be days or weeks, depending on the utility and the season.

On the first day of operation, check that the monitoring app shows production, that the inverter shows no faults, and that you have the commissioning paperwork, the warranty documents and an as-built drawing. Keep them with your solar paperwork and tax records. Regular care is described in solar panel maintenance.

What does the homeowner need to do on installation day?

• Give access to the roof, the electrical panel and the inverter location.
• Keep children and pets away from the work area and ladders.
• Expect a short power interruption when the crew connects to the main panel.
• Ask the lead installer for the schedule and any weather delays; snow, ice and high wind can stop roof work.
• Walk the site at the end of the day and photograph the work.

For a checklist of questions to settle earlier, use the solar installer checklist. Installation of solar heat collectors at Drake Landing, where 800 collectors went onto garage roofs, is described on the solar collection page.

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