what happens during a solar site assessment

What Happens During a Site Assessment for Solar and Battery

Solar Panel / Battery Site Assessment

When searching for a solar panel installer, you could Google "solar company near me" and choose one, but all solar companies are not the same. One of the most important parts of going solar is evaluating whether your home is in good condition for solar. This inspection is the first step after the contract is signed. Reputable solar installers will go to your home in advance to ensure that you can get an idea of what to expect when you start your solar process. 

A complete solar site assessment includes evaluating your home's electrical system, shading, and roof. In this guide, we hope to provide an overview of what to expect when you start going solar and why we are the best solar company to handle your solar panel installation and roof inspection

What Solar Installers do When Conducting a Solar Inspection

Forme Solar Electric's Solar Site Assessment process is intended to provide homeowners and builders an assessment of whether their home has the proper physical orientation to support a future installation of a solar panel system. This process evaluates the proposed site's solar energy potential based on known factors about the home, such as the electrical system, the home's location, and any anticipated shading. A site assessment aims to identify that the house will safely support a cost-effective solar panels installation. The structure of a site assessment will be to identify three (3) areas: 

  • Roof Analysis - Roof Type, Condition, Space
  • Electrical System Analysis - Load Center, Breakers, Grounding
  • Production Estimates Can Be Met - Shading, Azumith, Roof Planes

Site Assessment - Inspecting Your Roof

Knowing where you are placing your panels is extremely important. The location and structure that support your solar panels are vital to your solar system's production. In addition, because roof penetrations need to be made to add the mounting structure for your solar panels, we need to ensure that these penetrations are secure and weather tight. Because your solar energy system should last for more than 25+ years, your roof should also be in good condition. Otherwise, the cost to repair your roof after your solar panel system has been installed can be even more costly and time-consuming. This is why the process of inspecting your roof for solar is so vital. 

Interior Roof Inspection Procedure:

Often a roof inspector will look at the ceiling of your attic first. Any problems with your roof will also show up here. Then they'll look through your house for signs of trouble. They will be looking for insulation issues, ventilation problems, and any mold or mildew. All of these can be early signs that there is trouble with your roof.

attic solar panels inspection

External Roof Inspection Procedure:

Measurements of Solar Panel Layout and Access

Forme Solar will take measurements on your roof to ensure that we can meet the proper panel count. This allows us to provide a highly reliable analysis of how many solar panels could adequately fit your roof space to make it easier for our engineers and installers. 

Shade Analysis and Evaluating Nearby Surroundings

Our Solar Site Assessment experts will examine the influence of the area surrounding where the solar panels will be installed. This includes trees and vegetation and general topographic suitability. 

shade analysis

Roof Conditions and Paper

solar roof measurement inspection paper

They will then proceed to the outside, looking for factors like signs of aging, any weather damage to roofing tiles, any leaks or loose shingles, and many more. The goal is to get an idea of your roof's health so they know what needs to be fixed, replaced, upgraded, or stabilized before any other work is done. They'll also look at your gutters and ensure you have proper drainage to have no problems in the future.

Site Assessment Evaluating for Roof vs. Ground Mounted Systems

98% of solar panel installations are roof-mounted. The evaluation of the site for both roof and ground-mounted systems is relatively similar. However, there are some nuances that a solar company must determine to assess the location of solar panels correctly. 

Roof Mounted System

  • What is the roof age and condition?
  • When was the rooftop last replaced?
  • What is the tilt, angle, and orientation?
  • How many stories is the building?
  • What type of building is it?
  • What is the roof pitch?
  • Will the roof be susceptible to leaks?
  • What are the best roof planes, and how many panels could they fit?
  • Are there any obstructions on the roof, like vents, chimneys, or HVAC units?

Ground Mounted Systems

  • What is the grade of the land?
  • Distance to load center system?
  • What are the adjacent surroundings from foliage to soil conditions?
  • Will trenching be required? Concrete trenching?
  • What is the tilt, angle, and orientation for the layout?
  • What is the area currently being used for?

Site Assessment - Inspecting Your Electrical System

Your home's electrical system is critical to going solar. Your electrical system is heavily scrutinized and inspected to ensure that it can adequately support the maximum generation capacity for the system. The goal of a site assessor when evaluating your existing electrical system is to determine: 

  • Can the current electrical system safely support the size of the solar energy system you wish to install? 
  • What is the voltage of the incoming power supply and the number of phases?
  • Does the site have the minimum power factor required by your utility to support solar? 
inspect solar electrical

38% of Forme Solar customers who went solar in 2020 required a panel upgrade. The Main Panel Upgrade (MPU) is a service where your current electrical load center is upgraded to support your new solar energy system properly. There of the most common reasons why you may need a panel upgrade are: 

  1. Not Enough Space - The breakers in your electrical breaker box cannot handle the additional electrical load provided by a solar panel system. 
  2. Outdated Breakers - Another reason you may need a panel upgrade is if your home's electrical breakers are obsolete. 
  3. Unapproved Electrical Systems - Some older electrical panels are dangerous and should be replaced to reduce the risk of an electrical fire in your home.

Can the Site Match the Expected Production Estimates?

Shade Production Analysis

Shade can dramatically affect the production of your system. Trees and obstructions that cause shade are one of the biggest obstacles to your solar production. The sun's position year-round needs to be considered concerning the impact of shade. If your solar panels may be subject to a good amount of shade throughout the day, then we may recommend trimming or removing trees to improve your solar panels' energy production. 

Sufficient Space on the Roof 

The amount of space available is significant. Solar panels on your south-facing roof planes will produce the most electricity because they receive the most significant amount of sunshine over a day. While still suitable for solar, Eastern and Western facing panels produce less electricity overall because they see fewer "sun-hours" throughout the day.

If you do not have sufficient space on your roof, the number of solar panels that could fit can be limited, and you may be forced to use roof planes that aren't as well suited for solar. Everything from vents, HVAC units, chimneys to city Setback laws and restrictions can impact the space available. The importance of setback restrictions is to create safe pathways for the fire department to access your roof. This means that there needs to be adequate space from the top of the roof's ridge to the sides of the roof edges. The amount of space can impact 

Azimuth and Tilt

tilt azimuth degrees roof

The azimuth and tilt of the solar panel system (whether it be on your roof or ground-mounted) will substantially impact solar. The recommended tilt of your solar panel system can vary depending on which hemisphere you live on and how the sun rotates across an entire year. For most homes in California, the optimum angle of your solar panels to reach maximum electricity production is a 30 to 45-degree tilt to ensure it can be exposed to the highest amount of sunshine. 

Solar Production Estimate Update

Finally, an excellent solar installation will let you know immediately after your site assessment if there are any areas of your home that could raise any issues concerning installing solar. We take the time to discuss all the potential problems and develop a customized solution that ensures your solar energy system will correctly perform for the next 25 years. 


In a perfect world, you'd like a one-stop shop - a solar company that is both an expert in solar panel installation and conducting site inspections. This ensures that the solar production estimates you are estimating are correct. It also reduces the chances of roof leaks and electrical fires. Our site assessors look at your roof and electrical system to determine what it takes to install a safe solar panel system. It also saves you the time to coordinate between multiple companies to inspect your electrical system and roof. 

Forme Solar is a full-service solar company. We are a complete solar installation company that helps our customers from start to finish, from sales, to onboarding, site assessment, engineering, permitting, and utility company. We offer post-installation services after the work is complete—all backed by the best warranties in solar. 

Don't believe it? Forme Solar is a preferred partner of leading solar companies from LG Solar, Q CELL, Tesla, Panasonic, and Enphase. We are consistently ranked as one of the best solar installation companies across EnergySage, Yelp, Google, BBB, Houzz, and other review sites. Furthermore, we are recognized as one of the top 8 solar companies in the USA on BestCompany in 2020. This helps highlight the recognition of the quality of our solar installation experts. Proof that we stand behind quality work.

Solar FAQs for Site Assessments

How long does a site assessment take?

Site assessments typically take about an hour or two for a residential system. Usually, the longest part of the site assessment will be on the roof, analyzing for shade and taking measurements.

Do I need to prepare anything beforehand?

Only if you have any obstructions or pets that could interfere with someone going on the property. Otherwise, there is no need to prepare anything in advance.