Selecting a solar contractor to install your solar panels | Searching for Green

Today I had an email exchange with a gentleman interested in my experience in selecting a contractor to install my solar system. While I don’t want to name the companies yet on this blog, it occurred to me that the list of questions I’m asking may be useful for others. Many thanks to Dan from Daily Home Renovation Tips, who added quite a few to my initial list.

The problem with solar systems is that they are supposed to work in harsh conditions for many years to come. If anything is not done right at design or install time, fixing could be costly. So choosing the right contractor is of major importance. And don’t bet too much on warranties! Any warranty is as good as the company behind it. Guess what happens to a company doing a few botched installs? They will be belly-up in no time, and if you are one of their unlucky customers, you’ll be digging in your wallet!

Here is the list and some comments (in italics). Some questions are just for control, to see if they really know the field or just talking from a sales script :-)

About the solar panels:
  • panel technology: thin film, poly-crystalline or mono-crystalline. Stay away from thin film on your roof, unless you have an acre of it.
  • panel manufacturer and specs (power, dimensions, etc), manufacturing location (Ontario by chance?)
  • glass thickness? I didn’t heard any reports of it breaking, but at least one manufacturer claims it uses a thicker than standard (3 mm) glass.
  • orientation/tilt angle? this is a control question, everyone should know that the optimal tilt is 30 degrees
  • how much do I lose for a less than ideal orientation (azimuth and tilt)? I don’t expect too much from this control question, and indeed, the most frequent answer is “not much”
  • manufacturer warranty details
  • manufacturer output warranty. This is a black hole. Everybody offers it, but the discusion closes quickly when I ask details about how it works. I’ll have a separate post about this.
  • panel price, separately. This is not an important question, I’m asking it just to compare the Canadian prices to the US ones.
About the mounting rack
  • rack material: aluminum, stainless steel, galvanized steel. Galvanized steel is a deal breaker for me. Do you know those rusty antenna towers installed by the houses in older neighborhoods? That’s galvanized steel after 20 or 30 years!
  • height of the panels against the roof? Usually 4″, but only 3″ for some. The bigger the gap, the better the panel ventilation and cooling.
  • how many holes in the roof? Control question. The good answer: we should drill in the rafters, so we have to find them. It may be a too easy question, though :-)
  • do they use flashing on the roof? Many use just some rubber pads under the legs. I’m old school, I prefer metal flashing.
  • what kind of fasteners? Nothing less than stainless steel!
  • ask for a detailed picture of the leg assembly. This will make a difference for me, since everybody should be able to show a picture of their work! Unfortunately, only a few could provide it to me. I don’t need it on the spot, it’s perfect to get it later by email…
About the inverter
  • serial or parallel connection? This is a control question, only the parallel connection is currently accepted.
  • micro-inverter opinion? advantages? downsides? how much more expensive than centralized inverter? This questions will help me select the solution. Of course, the central inverter guys will tell me the disadvantages, while the microinverter guys will tell me about the advantages. In the end, I will have the full image.
  • communication/diagnostics to monitor production and to see when it fails? Is it subscription-based? I will not put the panels on my high roof and then wait 2 months for the hydro bills to tell me if they were working properly or not! For me, remote diagnostics and reporting is essential. I will not be willing to pay too much for it, though! IMO, some basic reporting should be available free of charge. I don’t necessarily need fancy online websites, but local computer access to the inverter is mandatory.
About the installation
  • written guarantee to pass any subsequent on site microFIT audit / inspection. Anyway, a part of the payment will be held until everything is working.
  • is a building permit needed? This is a control question and a possible muddy issue. Some contractors say yes, some say no, and a third group say it’s  a grey area.  Do your homework and know the city requirements in advance.  Some contractors don’t really know the specifics of your location. This may understandable if you are the first installation they do in a small town, but I don’t accept this for Toronto.
  • cost for removing and reinstalling the panels before/after re-shingling. Hopefully the panels will be on your roof  for way more than 20 years, and probably you will need to reshingle during their lifetime. Maybe the roofers of those days will be able to remove and reinstall everything, but I  don’t count on it. So I want to know in advance the costs. Of course, nobody will give you a price valid for 20 years, so I usually ask what would be the price if I would want to do this operation next week.
  • installation warranty
  • written guarantees against roof water leakage & damage. Hard to get, but not impossible. Some will just tell you “It never happened to us in the last XX years”. Yeah, sure!
About the financials
  • what is included in the price? what is not included? Permit, connection fees, ESA inspection, etc.
  • is financing available? Secured or unsecured credit? What interest rate? Bigger companies may have some financing arrangements. I have yet to find a reasonable one. HELOCs at any bank doesn’t count as an arrangement, since I can get that myself.
  • when is payment due? I understand the need for a partial advance payment, but no more than 50%. And I want to hold at least 5% at the end, until everything is approved and running.
  • about utility connection fee and meter fee. This is a control question. Do your homework in advance by calling your utility. Again, it’s not acceptable for me that my installer doesn’t know these fees for Toronto Hydro! But it may be acceptable for a small town.
  • local references. This is mandatory. If they don’t have any installations in Toronto, I don’t want to be their first one.
  • for how long are they in the business? What is their main business? How did they survive before microFIT? This is to select the real solar guys from the rest. I don’t want my system installed by some roofers helped by an electrician.
  • are they using subcontractors? I would prefer no subcontractors, but it’s not mandatory.
  • process duration. Control question, they should know the current backlog at OPA.

OK, now it’s your turn. Please let me know in comments if you have any questions that one should ask, and I’ll gladly add them to the above list.


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