Last month I met site surveyor, Mark, at a client’s house for the site survey. SunStor Solar had put together a system proposal for the homeowners a couple of days earlier, and I was anxious to confirm their roof was suitable for solar. One of the reasons for my concern was that some other solar companies told the customer it wasn’t.
SunStor arranged for preferred partner American Home Energy to do the installation, and AHE was taking the first step of verifying the information they already had.
Mark drives all over northern California doing a few site surveys per day. He estimates he has completed over 600 of them in his seven years in the solar industry. [Update: a month later, he was up to 650.]
Typically, we set the site survey appointment within a small window of time, and it lasts an hour or two. When I arrived (actually on the dot) he was just introducing himself to the homeowner and explaining what he would be doing.
Bottom to Top
Mark started by locating where the utilities enter the property. In this case, the electrical lines were underground, not on utility poles. He photographed the access cover in front of the house.
While he did that, I found out that his background includes PV energy and a number of related areas of expertise, education, and skills. He exuded a genuine enthusiasm about his work and was happy to share his knowledge.
Moving on to the home’s main electrical panel, Mark then took several additional photographs. These included photos showing its location on the wall of the garage, proximity to the gas meter, the space available for mounting the solar equipment, and the inside of the panel showing all the breakers.
The designer doing the CAD drawings must determine where to mount the solar equipment and emergency shut-off switch, and to run conduit, so that the city will grant a permit. Also, the electrician determining whether there is sufficient capacity in the main panel to make it suitable for the solar connection, can do that from the photo, before he reaches the job site.
Building Codes and Electrical Connections
Local jurisdictions in charge of building codes often change them, and cause them to vary, not just from one jurisdiction to another, but from one year to the next. That’s why these photos are useful to answer any questions the building department or the electrician might have.
I had already noticed that the builder of this subdivision installed gas meters right below the electrical panels. Because this is no longer the practice in most of California, it concerned me. All the more, because I knew it was common in this area of Martinez, built in the 1980’s, and so many of the neighbors investigating solar. Today, gas and electrical meters need a separation of three feet, typically.
If the main panel has to be upgraded, the city might require the panel to be moved further away from the gas meter, to bring it up to current code. Pool and hot tub owners, especially, may have maxed out their main electrical panel.
Upgrading the main panel is somewhat expensive, as it requires an additional permit application and the project’s licensed electrician will need more time and materials. Doing such an upgrade also requires the Utility’s cooperation, and the power may be shut down briefly.
Moving an electrical panel complicates things further, especially if the connections are too short! Alternatively, a subpanel is sometimes added, instead. Our qualified solar electrician frequently does these, if needed.
Fortunately, my client’s main panel looks good, and we won’t upgrade or move it. In other words, left undisturbed, it is grandfathered in on the code changes.
Solar Suitability Over Time
Luckily, time is on your side with solar. Owning solar or having a prenegotiated rate with a PPA, shields you from inflation. When the CPUC approves higher utility rates, the higher electric rates also mean more tax to pay. In addition, if there is a utility tax, the locals may raise the tax rate, too. So far, no one is taxing the Sun.
Adding a new main panel may delay payback, but, eventually, solar electricity savings usually covers the cost of an upgrade.
Of course, there are exceptions for very small electric utility bills, especially with an income or medical discount, or for a roof that does not get enough sun. Unfortunately, California now mandates that builders of new, energy efficient homes with very small electric bills, must sell them with solar modules/panels, anyway.
Building Codes and Solar Suitable Rooftops
Upon completion of the outside electrical hook-ups, Mark also photographed the electrical sub-panel in the garage, before moving outside, to the roof. First, he set up the extension ladder.
If the roof is in poor condition, or is already leaking or about to leak, we won’t install solar on it in that condition. The installer warrants our solar installs won’t leak, so they can’t afford to take the risk.
Installation warranties vary in length (5-20 years). Typically, they apply against leaks due to their roof penetrations, and a long warranty isn’t needed assuming it rains enough to test it out within the first few years. The solar modules, inverters, and other equipment is covered by the manufacturers’ warranty, and these typically last longer (20 to 25 years).
TAX TIP: Did you know there are tax credits available on re-roofing expenses for the purpose of adding solar? Also, for main electrical panel upgrades and moves, tree trimming and removal, and other improvement costs incidental to solar installation. Consult your tax advisor.
Metal Roofs Take Extra Care
Mark climbed a ladder to look at the roof up close. This roof was an old wooden shake roof covered in sheets of thin metal made to look like clay tile. We know there was wood shake underneath, because he lifted one up to look and took pictures.
Because this is more economical than removing and disposing of old wood shakes, and/or provide some fire resistance, these are common all over Walnut Creek, Pleasant Hill, Martinez, Concord, Pittsburg, Antioch, and elsewhere. He called the sheets “stone coated steel.”
He looked for signs that the roof was nearing the end of its useful life. Although this roof wasn’t new, he determined that it appeared to be in good condition. Stone-coated steel roofs often have a 50 year warranty.
The thin steel sheets are notorious for showing footprints. So, he took photos of some footprints already present.
Normally, while on the roof, Mark would also use a device that measures and calculates where sun and shade would fall on the roof at different times of the day and year. But he decided not to walk on the roof, to prevent more footprints.
Because there were no trees nearby, his project manager confirmed by phone that the measurements wouldn’t be necessary to determine if there was enough sun to be solar suitable. They can confirm this data from other sources.
He also noted all the vents, the chimney, and looked for skylights, and for satellite dishes, and other obstacles.
Outside, Inside: Attic Parkour
Then, we moved into the house. Access to the attic was through the ceiling in a closet, and involved what Mark calls, ‘Attic Parkour.”
Fortunately for the installer’s insurance costs, Attic Parkour requires some gymnastics, but is much slower and more careful than regular Parkour.
I used to own a 1920’s home, and if I had water leaking underneath it, I would request “the skinny plumber.” It follows that, if site surveyors have have to fit into the attic, some flexibility is a job requirement.
DVC Classes Pay Off
Last century, I took some architectural working drawings classes at Diablo Valley College during the summer, and they were now paying off!
Mark took photos of the attic framing. I didn’t get a full list of the odd things Mark has seen in attics, but one time, he said, someone had cut all the framing. I’m aware of another instance where there was evidence of a fire.
Such problems can mean a roof is not suitable for solar.
To be suitable for solar, a roof must be sound. Today’s solar modules are lighter weight than earlier ones, but weight isn’t the main concern. You don’t want your solar panels to became airborne in a high wind, and, perhaps, take the roof with them, either.
Additionally, installing solar modules in snow country requires us to anticipate snow loads.
It’s not difficult to remove and replace solar modules if a re-roof is needed in a few years, but no one wants to install solar if the roof is already failing. But, it’s also true that shade from the solar modules can actually extend the life of the roof, beneath.
Solar Suitable Bones
One of the potential challenges of this roof is that the original builder installed wood shakes over skip sheathing, where the sheathing has gaps. Current code calls for continuous sheathing. The site surveyor looks for this type of thing, in case the city requires this to be changed.
If the building department requires continuous sheathing (usually plywood or OSB) to augment or replace skip-sheathing, it would basically consist of a re-roof job, at least for the portion under the solar installation. We might have to revise the budget if that were the case.
Metal Roof Suitability for Solar
Fortunately, when we prepared the proposal, we were aware of the steel roof, and would not need to revise the cost on that account, alone. I was more concerned about the shake and skip-sheathing, beneath, but Mark didn’t think it would be an issue, either.
He explained that this was because the waterproof layer of a steel roof, is on the top. The special mounting hardware made for steel roofs like this one, don’t require making any penetrations in the top layer, preserving the integrity of the roof.
Update: He was right. In this case, the City approved the use of the special connectors, and they weren’t concerned about the old wood shakes or the partial sheathing causing a problem.
These are normal “problems” we encounter in rooftop solar, none of which mean the roof isn’t suitable. Sometimes, however, cost is an obstacle, because it impacts the return on investment.
Roof repair and prep costs can be rolled into the energy tax credit, as well, should they be needed to make a roof solar ready.
Finally, we put everything back in the closet, swept up the dust under the ladder, and said goodbye to the homeowner.
Mark then sent the information to the installation company, allowing them to proceed with the solar drawings and permit application.
Have you ever been told your roof wasn’t suitable for solar? What were the reasons given? How long ago was it? Please comment below, and Bookmark, Like, Share, Follow, or Subscribe. Contact me with questions or suggestions.