Hey Rob,
I've had solar panels installed on my home in San Diego, CA for about four years.
These would be some of my questions:
- Do you warrant both the labor and equipment, and for how long?
- What brand of panels do you use and how do they compare to competitors?
- What is your company's reputation rating by independent reviewers? [in the U.S., this would be Yelp and/or the Better Business Bureau (BBB). You might also Google "best solar installers in my area" and read user reviews]
- How much extra would it cost to add a storage battery (e.g., Tesla) at the same time?
- What is the estimated payback time (break-even) to recapture the costs of the panels, and the battery?
- Does the government subsidize my costs through tax credits or otherwise?
- What software do you provide so I can monitor my solar energy capture and my usage?
- Can you provide me with the names and numbers of your recent customers as references?
- Will you repair my roof if the installation causes damage (like water leaks)?
Our gross cost four years ago to equip our 2600 sq-ft home was about $22,000. I don't know if you would require more or fewer panels due to your less sunny location.
Good luck, Rob!
Tom