The All-Important Solar Site Survey

Solar Site Survey Photo
The All-Important Solar Site Survey 5

One of the most important steps in the process of going solar is the site survey. This is where the solar company will do a thorough inspection of your home to make sure it is suitable for solar. I say thorough inspection but, it has to be said that some are more thorough than others. 

In the name of “efficiency”, some solar companies will carry out site surveys remotely, using aerial images, online data, solar design software, and photos provided by either the homeowner or the sales rep. 

I don’t like this trend. While it may be quick and painless from the homeowners perspective, and cheaper for the solar company, it’s unlikely to uncover any but the most glaring problems.

A more comprehensive in-person solar site survey may uncover some bad news, and may even disqualify your home but, believe me, it’s better for everyone to find out early in the process rather than later.

The site survey is not a part of the solar process where you want to take short cuts. 

In this article, I’ll walk you through what typically happens at a site survey, what sorts of things the surveyor is looking for and what it means for the likelihood of your solar system going all the way to install.

When Does a Solar Site Survey Take Place?

The solar site survey typically takes place about a week after the solar sales rep has presented the preliminary designs and the customer has expressed a firm interest in at least exploring solar, usually by signing off on a preliminary agreement. 

While it’s tempting to think that the parties have committed if there’s an agreement in place, it’s not until the site survey has been completed that either party truly knows what the possibilities are. 

So why even bother with a preliminary agreement, you may ask. 

That’s because performing a site survey is expensive. In fact it’s likely the first time that the solar company has committed to spending real money exploring the solar potential for your home. (The sales rep was probably a 1099, commission-only “expense”). So in order to justify that investment, the solar company needs to know that the customer is more than just a tire-kicker.

Site Surveyor With Ladder
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The site survey will also likely be the first time that the solar company has employees on your property, possibly climbing ladders and doing other “risky” stuff, so they want to make sure those employees are covered by workman’s compensation.

What Happens at the Site Survey?

There are seven main areas a solar site surveyor will examine and report back to the head office.

1. Confirm Sun Hours

While the satellite image you are shown by the sales rep is a great place to start a conversation about solar, it can only take you so far. After all, a typical satellite orbits the earth at an altitude of over 100 miles. Your solar company is going to want to take a closer look.

A good site surveyor will be trained to use a hand-held shade measuring tool like Solmetric’s SunEye-210. It’s probably the leading shade measurement tool on the market today. A solar site survey that doesn’t utilize it, or something like it, is not going to be able to accurately assess how much sun your roof gets.

2. Identify Shaded Areas

Satellite images are notorious for being out of date. I can’t count the number of times I’ve sat down with a customer for a solar consult and been somewhat embarrassed to be told that the image I was showing them was from several years ago. 

Often the customer can easily tell from the color of the car in the driveway, or the clear image of the boat they sold years ago. Out-of-date images, of course, become a critical flaw when it comes to assessing shade. 

Trees grow over time, or get trimmed back. Deciduous trees lose their leaves in winter and, so, cast a very different shadow than they do in summertime. An in-person solar site survey will accurately identify which trees are likely to cast a shadow on the roof and even assess what effect the removal of certain trees might have on sun hours.

I’ve been able to take deals that were marginal because of a shady roof and turn them into great deals for the customer simply by explaining that, if they removed that tree, it would improve their sun hours by this amount.

3. Examine Roof for Obstructions

Obstructions on the roof can also impede the placement of solar panels. These are usually vents, TV satellite dishes and other small obstructions that can easily be missed in an aerial photo.

Roof Vent Cropped
Roof Vents Can Cause Havoc With Solar Panel Placements

A good site survey can identify these, assess the feasibility of moving them and give the design team crucial information that will help them to create a better design.

4. Identify Roof Pitch

Roof pitch is another thing that is difficult to assess from a satellite image. Roof pitch is a critical factor since it plays a huge role in the angle at which the panels are installed, as well as the safety of the installation crew.

A roof with a steep pitch will just be more difficult to work on and may require the crew to take more time with the installation. On the other hand, a roof with an extremely low pitch (less than 10 degrees) may require a rubberized roof to be installed to prevent leakage, which itself will require the solar installation to be done in warm weather.

5. Check Roof Condition

Roof condition is one of the most important factors to consider when deciding whether to go solar. This is true for both the solar company and the customer. In New England, where I work, and where the housing stock tends to be older, over 50% of the solar projects I work in involve some kind of conversation about the roof.

A thorough solar site survey will give a full assessment of both the quality of the shingles on the outside and the structural integrity of the roof to be sure it can take the extra weight of the panels.

6. Inspect Main Service Panel

The inspection of the main electrical service panel is arguably the most important job at a solar site survey. After all, the whole point of the exercise is to bring electricity into the house so assessing how the solar system will be interconnected to the home’s electrical system is a pretty big deal.

Add to that the fact that electricity can be very dangerous if not managed properly, and it becomes clear that it’s best to have a licensed professional inspect your panel. 

An expert inspection of the electrical panel will help determine the busbar rating, the amp service, the number of available circuits and what kind of equipment and/or service upgrades may be required. (Did I mention that this needs to be done by a licensed professional?)

Electrical Panel Inspection
The All-Important Solar Site Survey 6

7. Take Lots of Pictures and/or Video

Nobody wants to go back to a house and do a second site survey because they failed to gather enough information at the first. That’s why a thorough solar site survey will always involve taking lots of photos. And videos, too. 

It’s far better for the design and engineering team back at the office to spend time sifting through dozens of photos than it is to have them wish they had that one shot that accurately reflects the precise part of, say, the roof that shows whether it needs repairing.

What Happens After Site Survey?

Once the site survey is completed, the solar company gathers all the information and comes up with a final design. This may differ substantially from the one that was shown by the sales rep, or it may be pretty much the same.

More importantly, the solar company will have a clear idea of what, if anything, needs to happen by way of upgrades before the solar installation can go ahead. The rep will then come back with all this information and explain what it all means and how it’s going to affect your solar project.

 If home upgrades are needed, who is going to do them and who is going to pay for them? How does the need for upgrades affect the customer’s price? Does the need for upgrades make a PPA more attractive than a cash purchase? Or does it kill the whole deal?

Final Thoughts

Most people mistakenly believe that the process of going solar is basically the same for everyone, when the truth is that every house is its own unique project. 

There are many factors that need to be taken into account and it is only after the survey is complete that the customer, the solar company, the town and the utility can have a clear idea on whether a home is a good candidate for going solar.

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