Solar Panel Installation

Installing Rooftop Solar Panels: What Homeowners Need to Know

You’ve been considering it for some time now and are finally ready to make the leap—the financial and environmental benefits of solar panels have officially won you over.

Now that you’re ready to harness the power of the sun in your home, it’s time to roll up your sleeves and learn how it all works. Although the process is relatively simple, there’s more to it than just throwing some solar panels up on the roof.

Before the Roof, the Groundwork

First you’ll want to evaluate your current energy usage and average monthly electricity costs. Typically, the higher your monthly electricity bill, the more you can expect to save with your rooftop solar system.

A recent utility bill can tell you how many kilowatts of energy you use on an average day. You should also anticipate any future changes to your energy consumption: Is anyone moving in or out? Do you anticipate spending more or less time at home? Do you plan to add a home office, swimming pool, or an electric car?

Next, take a stroll around your property, looking at the condition and orientation of the roof. The amount of electricity a solar panel produces depends not only on the efficiency of its solar cells and its size, but also on how much direct sunlight the panels receive. The more hours of direct sunlight, especially during peak hours, the more effectively your system will work, and the more electricity you’ll produce. A south- or west-facing roof is ideal for capturing those peak daylight rays.

“Insolation” is another term to have on your radar. This is the amount of solar radiation that strikes a given area (like your property) over a period of time, such as in a day. Insolation differs by region, which is why a solar-powered home in the Southwestern United States will be working at a very high efficiency rating compared to a home in the Northeast, for example.

Regardless of your region, you should also be aware of any “shady situations” that may affect your solar panels’ efficacy: cloud cover isn’t really a problem, but you should make note of trees, chimneys, your neighbor’s popped-top addition, or other structures that cast shadows or otherwise reduce the direct sunlight that reaches your rooftop. Also ask yourself if there is any place on your roof you do not want solar panels installed.*

Finally, evaluate the condition of your roof and your electrical circuitry system. Are your electrical circuits in good condition? Are you due for a roof replacement in the next twenty years? If so, you may be able to get financing to combine the solar panel installation and a new roof.

Doing Your Homework: Budget and Professional Installers


It’s worthwhile to have an idea of how much you want to spend up front. There are many financing options and tax credits available for leasing and buying—how much do you want to come out-of-pocket?

Keep in mind the potential costs associated with any necessary home upgrades (roof, circuitry), and don’t forget that your homeowner’s insurance premium may increase slightly once the system is installed.

During your consultation with a professional installer, you can ask about the cost of installation, payment options, and available rebates, and also get an idea about how much you can save. The more electricity your panels generate, the less you will need to buy from your utility, which means lower bills. If you live in an area where “net metering” is available, you can also save money with a bill credit for extra electricity your system produces.

Now that you have evaluated your current energy usage and costs—and have a good idea if any home upgrades are needed—it’s time to call in the experts.


A professional installer will help you further evaluate which solar panel options will work with your home. It’s a good idea to meet with several installers before making a final decision. When researching companies in your area, look for a company with a good track record (check with the Better Business Bureau, for example) and make sure they’re experienced in residential installations. The U.S. solar industry has grown tremendously in recent years, and reputable, experienced firms have set up shop in many states.

After a conversation about your energy usage, savings goals, and financing preferences, the installer will perform a detailed site survey and analysis. This will include measuring the roof orientation, slope, covering (e.g. slate, metal, shingle) and condition, as well as the irradiance (the flux of radiant energy) and potential shadow issues on your property. If all signs point to go, a site surveyor will visit after your consultation for further measurements.


How Many Panels Will I Need?

The size of a system depends on insolation (the amount of solar radiation striking your property in a day), how much energy you need to produce, and the efficiency of the panels themselves. A typical solar panel produces about 200 watts of electricity based on the efficiency and size of what’s installed. Solar panel efficiency is particularly important if your roof space is limited or partially shaded—the more efficient your panels, the fewer you’ll need.

The site surveyor will perform structural calculations to ensure your roof can support the load of system. The surveyor also will look at your electrical circuits to make sure they are suitable for a PV solar connection.

With these measurements, engineers will get to work designing a customized system for your home. Most will provide a diagram so you can see what the system will look like on your roof. At this point your installer also may provide an agreement outlining your fixed energy cost for the next 20 or more years.

What Should I Consider When Selecting an Installer?

Once you have a few bids, it’s time to compare them to choose the installer and design that will work best for you. You might consider questions like: Do they provide free system monitoring? Insurance? Repairs? A maintenance plan? What types of guarantees and warranties are in place to protect you and your home? What happens if you have trouble with the system?

In terms of cost, ask about installation costs and how you will make electricity payments once your home starts generating solar energy. For example, ask if you’ll be making monthly payments, and if your bill will be the same every month.


How Long Will the Process Take?

Once you have signed a contract, it’s time to set things in motion. Your installer will handle the rest, so just sit back and watch the magic happen!

The next phases can take anywhere from a few weeks to a few months, depending on the installer, the city, your schedule, the time of year, and so on.

  • City permits: A permit is a must. Types and costs vary by municipality, but your installer usually handles this.
  • Wiring and installation: Once scheduled, this is completed within a few days (often a single day).
  • Pass a city inspection: Your installer can handle this step as well. The wait for an inspection varies based on demand.
  • Net meter installation: If net metering is available where you live, your utility company will install a net meter that connects your new system to the grid, then give you the green light to turn it on.

Congratulations! Your solar system is installed. You’ve significantly reduced your demand for utility power, cut back your use of dirty energy, and positioned yourself for more affordable power for years to come.

*Note: In some cases, homeowner associations prohibit panels that are visible from the road. Fortunately, this is rare. Most people now understand that solar adds value to a property and will impress real estate shoppers who are exploring the neighborhood.

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