Top Five Ways to Spot a Bad Roof in a Solar Site Assessment

Before being able to install solar panels on any roof, performing a solar site assessment is critical in order to properly design a solar system.

From a sales perspective, it is key to know what to look for instead of wasting any time on roofs that are not well suited for a solar system.

Although spotting a good roof can be pretty easy, spotting a bad one is a little more of an art, so here are the top five things to look out for in a roof that may not meet solar site assessment standards.

1. Shading

   . The number-one talked-about aspect in solar installation is shading, but why is shading so important? If a roof has full sun for one hour with 8 Sharp, 208 watt modules, it will be produce 1200 watts-hours. If just one cell, in one module is shaded, production will drop to 1100 watts. If one full module is shaded, this figure drops to only 900 watt-hours. Note that a single cell is about two by four inches. A lot of roofs will fall into two categories; no shading at all or completely and obviously shaded. For determining whether or not to install on a roof in the middle of the spectrum, use a Solar Pathfinder.

2. Old Roof.

   Regardless of how much power an installation is able to produce, if the roof leaks, the outcome doesn’t matter. Also, once solar panels are installed, replacing a roof with panels on it is doable but a pain, and can be costly. Make sure to check the age of the roof and get the information for the warranting contractor if there are any questions. If the roof is in really bad shape, the homeowner will want to replace it before panels are installed.

3. Obstacles.

   Don’t get too cocky when looking to design a solar system around obstacles. If there are too many hindrances on the roof, panels may not fit, and it could be too troublesome to work on that roof at all. Some examples of obstacles are chimneys, stink pipes, complicated architecture and sky lights. This may not be the biggest deterrence in the solar site assessment, but it’s important to keep in mind when determining the probable success of the project. Having obstacles that completely hinder a project are rare, but they do occur.

4. Electrical Service.

   Most residential inverters need 20, sometimes 25, amp breakers for over-current protection. A homeowners existing service may not be large enough or have enough bays for a new breaker. It is vital to determine these limitations before starting to design a solar system. Similar to obstacles on a roof, electrical service will rarely mean a installation cannot be done, but it might make it more expensive, something you’ll want to keep in mind when quoting.

5. No Place for Conduit Run.

   Keep in mind that power needs to get from the roof down into the basement in order to tap into the existing electrical service. If the home owner is strictly against an outside run on the house for aesthetic considerations, if there is no attic, and if the entire inside is finished space, it may be impossible to get the power downstairs. This is rarely a deal-breaker but something that must be discussed upfront.

To go deeper on solar sales, marketing, installation, and design, check out HeatSpring’s free and paid solar training courses.

For more on solar site visits and assessments…