April 11, 2018 Solar Energy Written by Greentumble
solar panel installation
Solar panel installation procedures have

simplified over the last years making it possible for more than a million of U.S. households to go solar. However, even nowadays, the decision of going solar underlies a great series of permits, inspections, technical considerations and economic factors that can easily overwhelm any of us, and that can influence the decision of installing a residential solar power system.

But despite these overwhelming factors at the beginning, once you are on the way of becoming a solar energy producer you will realize that the pieces will start fitting and before you know it, your house will be supporting solar panels!

The idea of this guide is to provide you the necessary basics, to get an overview of all the process of installation, passing through the selection of the solar installer, the home site evaluation, the related design of the power system, permitting, interconnection and inspection processes, and finally, the big day of the solar panels installation.

#1 Finding a solar installer and getting a quote

Finding a good solar installer is crucial in order to obtain the best price-benefit relationship for your solar power system. Across the U.S. you will find many solar installers, but the key of finding the one that fits your needs is a balance between experience and price.

Customer service is also an important aspect, as it provides a good overview of the quality of the company’s services and the willingness to solve issues that could happen during the installation or even after, when warranty execution is needed.

Generally, solar installers provide free assessment and quotes in order to offer their services and have their chance to design your solar panel system. Remember that the market is evolving now, and therefore, you will find many installers eager to design a system for you.

Asking for several quotes from different companies is the most advisable thing to do.

To compare among available installers you must ask the company for a bid that should include:

    • The total cost of the PV system
      (connection to the grid, permitting, hardware, installation, sales tax);
    • The cost per watt;
    • The cost per kWh.

These are the best references to decide which company offers the most economical solution to your needs.

Other important things to consider

Despite money being a top decision maker, other aspects may also be important to influence your decision. Costs reductions are desirable, but there is a limit that should not be passed, as it could represent further losses in the future.

For instance, quality of equipment is a crucial matter. The ideal installer should provide a warranty for at least 20 to 25 years on the hardware, including solar panels and inverters. Such warranty will be an indication of the hardware’s quality and also of the good customer service.

Other aspect to consider is certification. An experienced solar installer will have a certification that assures the quality of installations and the approval of a technical institution.

In the U.S, the qualification is from the North America Board of Certified Energy Practitioners (NABCEP), this certification is an important indicator as the NABCEP assures that the installer meets the standards and qualifications of the most recognized and esteemed organization in the U.S. Solar Industry.

Questions to ask when choosing a solar installer

Also, do not forget to consider some of these questions:

    • Is the company familiar with important permitting and interconnection processes?
    • Is the company properly licensed with local building departments and state electrical boards?
    • Who will ensure the operation and maintenance of the solar system and what is the warranty of the system?

They shall be the complement answers you need to hear to complete your assessment and make the best choice.

You can also read more detailed overview in What Questions to Ask When Buying Solar Panels.

To get an idea of your solar quote before calling a particular installer you can check the estimated solar costs of your home design by using a solar calculator.

#2 Home and site evaluation

The site evaluation and inspection will include an analysis of the current electrical panel and wiring of the house, as well as the available connection to the grid.

This represents an essential part of the installation process as the company must determine whether or not it is necessary to upgrade the current electrical system, since it needs to endure a new power output of the solar panels.

In some cases, it is necessary to change the wiring, as the demand of the house could reach the maximum, and there could also be hotspots exceeding the ampere capacity of the installation, and therefore, posing a risk to the whole system and the household itself.

The installer should also check the state of your roof, to verify that the weight of the solar panels can be endured by the roof in the long term. The maximum number of solar panels is then determined according to the type of roofing, whether it is shingles, tiles or clay.

Once these aspects are covered, the installer must evaluate the roof orientation to take advantage of the maximum solar irradiance available in your area. While doing so, the assessment of the roof tilt is done as well, in order to adapt the design of the solar system to it.

The type of roof, tilt and orientation are important variables when deciding on the installation procedure, the number of solar panels and even the racking system.

It is advisable that you examine how much sunshine does your area get on average throughout the year. This will give you an idea of the overall efficiency that can be obtained in your location.

Currently there are many available tools and mapping resources that will aid you, some of them like PVWatt, Mapdwell and OpenEI are recognized as useful tools designed by the National Renewable Energy Laboratory and the Massachusetts Institute of Technology. They will surely provide the most accurate and valuable information that you can easily find on the web [1].

Considerations related to trees that may obstruct sunlight may also be pointed out by the installer.

#3 Design and permits: The paperwork you need to do for your solar panel installation

The solar installer should create a design of the system that includes:

    • Number of solar panels, their position on the roof and the type of connections between solar panels (series or parallel);
    • Selection of inverters and battery mix should also be included;
    • Wiring system (AWG size of cables according to voltage drop and ampere capacity);
    • Local fire safety requirements design;
    • Interconnection with the power utility. Inclusion of net metering should also be considered.

Within the design, the selection of the solar panels type (monocrystalline, polycrystalline or thin film) and the inverter (string inverters, micro-inverters or DC power optimizers) along with the battery mix and the controller will be the most important hardware requirements of the solar system.

Make sure the installer explains you why his or her design is the best suited for your household and why is it the best technical-economical choice.

These products will influence the total cost of your system.

Solar permits

Regarding the permits, the installer should present the final designs in your city permitting departments and the utility company as well, although the paperwork is generally done by the installer, it would be convenient to have an insight of the typical paperwork related to solar panel installations.

The first thing that must be determined is related to restrictions or requirements established by the local authorities regarding solar panel installations. Generally, these are known as Homeowner Association’s restrictions and they vary widely across municipalities.

Afterwards, building permits are also necessary, mainly related to ensure that the roof can handle the PV system weight, that the system is properly secured to the roof and that is not susceptible to wind damage or roof leakage [4]. In some cases, building permit evaluates the availability of space on the roof for the solar panels, as there are some building departments that request how many square meters will remain free on the roof after the installation [3].

As other electrical systems, the solar PV installations require in most cases an electrical permit. Generally these permits have a flat fee or have a fee based on the dollar value of the project.

Overall permitting process for building and electrical permits tend to last between 4-6 days [4].

Solar incentives

Applications for solar incentives are also an important part of the permitting process that should be performed by the installer. The Investment Tax Credit (ITC) may be one of the most important ones as the small solar energy systems will be eligible for a 30 percent Federal Tax Credit for all solar systems active by 2019, 26 percent in 2020 and 22 percent in 2021, unless the homeowner applies for a solar lease or power purchase agreement [1].

In order to apply for the ITC it is necessary to complete the IRS Form 5965 “Residential Energy Credits” and include it at the IRS Form 1040 (US Individual Income Tax Return) [2].

Among other solar incentives, you may find cash incentives including grants, rebates and even production–based incentive (PBI) like the programs in Austin, Texas or in San Francisco, California [6].

Furthermore, third-party residential financing models like solar leasing and power purchase agreements (PPAs) can also be implemented as conventional methods of financing your solar system, and will allow you to access solar electricity. Although, this would imply that you are no longer eligible for ITC.

The Property Assessed Clean Energy (PACE) program model is another financing method that you can discuss with your installer, as the programs deals with the up-front costs directly or through private investors. The owner can repay the loan over an extended period between 10 to 20 years through property tax assessments.

Discussing the available options in your State with your installer is probably the best way to find out the best financing and incentive option for you.

#4 The solar panel installation day

The big day has arrived! The installation day is gratifying for any homeowner who wishes to go solar. Gather your family to watch the show and watch your roof turning solar!

The overall process involves in the first place a preparation of your roof, making sure that the shingles or tiles are properly attached. After the roof is secured, installers will proceed to install all the electrical wiring of the system and connect it to your electrical box.

Finally, the racking system will be installed and then the solar panels (along with the inverters) will be put in place according to the configuration established by the engineer.

Moreover, in case the net metering is established an additional time of installation will be required. In most cases, the overall process of installation takes between 1 to 3 days depending on the size of the system.

#5 Approval and interconnection

Once your system is in place, there is still one final step to overcome – the approval of your system and the interconnection to the power grid.

The approval will come from a county specialist or inspector who will visit your house to make sure that all the electrical and mechanical installation of the system is secured and meets the standards of the National Electrical Code and along with other fire security norms.

The installation should have the same specifications as presented in the granted permit that included the design into the electrical and building permit.

When the inspector approves the installation, it is necessary to contact the utility company to make the final interconnection. The utility company will send an inspector as well to verify the installation and make sure the system meets minimal service quality requirements of the grid.

Once everything is in place, the utility company will authorize the switch on and you will be finally able to generate your own solar electricity!

Hopefully this step by step guide will give you a good idea of the overall process of a solar installation! Don’t forget to ask for advice to friends and neighbors who have done their PV system already, especially if they worked with the same solar installer!



[1] https://www.energy.gov/energysaver/planning-home-solar-electric-system
[2] https://news.energysage.com/how-do-i-claim-the-solar-tax-credit/
[3] https://news.energysage.com/solar-panel-installation-guide-what-should-you-expect/
[4] https://deq.mt.gov/Portals/112/Energy/EnergizeMT/Renewables/SolarPermittingReport.pdf
[5] https://us.sunpower.com/blog/2017/07/17/how-home-solar-panels-are-installed/
[6] https://www1.eere.energy.gov/solar/pdfs/47692.pdf