When it comes to residential solar panels, the roof is the most obvious place to put them. Not every home sits on enough land that they can put up an array on the ground, so placing them on the home is the next best option. But not all roofs are constructed to the same size or specifications. Some homes have roofs with steeper pitches, while others have more faces. This can lead to some confusion about how much space is needed for a solar panel installation.
When your clients ask about the roof requirements, it’s important that you have a clear answer for them. Fortunately, we’ve outlined some of the nuances of this answer below. Your solar sales job with Palmetto is made easier when you have the answers to your clients most pressing questions.
There’s No Clear Answer
We’d love to tell you an exact amount of square footage is required for a certain number of panels, but it’s not quite that simple. A residential solar panel array is custom made according to the client’s needs and the size of their roof. Of course, this answer isn’t an excuse to just shrug your shoulders when your clients ask you this question. Instead, you can explain what factors impact how much space they’ll need and how many panels they can support.
Energy usage plays a role
How many panels you’ll need, and subsequently how much roof space you’ll need, starts with an estimate of how much power you use in a given year. There are plenty of ways to determine your annual energy usage, but perhaps the easiest is to simply take a look at your monthly energy bill. It should tell you how many kilowatt-hours of energy you use in a given month. Simply multiply that number by 12 to get an annual estimate. Generally, the average American home uses about 11,000 kWh of energy every year.
Your location is important too
Different parts of the country get different amounts of sunlight. For instance, Arizona is famous for its intensely sunny days. On average, Arizona gets 300 days of sunshine a year. Conversely, Juneau, Alaska, spends more than two-thirds of the year bathed in darkness.
Depending on where you live, you’ll need more or fewer solar panels, and you’ll also need more powerful solar panels. So if you live somewhere with lots of sun, you might only need a few solar panels. But if you live in Juneau, you’ll want lots of high-powered solar panels.
Your budget is also a factor
Generally, larger systems are a great way to offset your current electrical and fossil fuel energy usage very quickly. However, larger systems are naturally more expensive. While you may have the roof real estate for a large array, you might not have the financial backing for it and vice versa.
The size and rating of the panels are important
Solar panels can vary in size and rating, leading to different results. Some panels might be smaller but have a higher watt rating. That means they’re more efficient than a larger panel with a lower rating. The type of panels your clients choose will affect how many of them they need.
So How Big Should Your Client’s Array Be?
Ok, so now that we’ve got all of the minutiae out of the way, let’s get to the real answers. There are some rules of thumb you can follow that can offer your clients a general idea of how much roof space they’ll need for their installation. Generally, every square foot of roof space has the potential to generate 15 watts of solar energy. The average solar panel installation on a home needs around 100 square feet of roof space for a smaller home and more than 1,000 square feet for a larger home.
Most solar panel installation services have found that the average American home typically needs 18 to 24 panels to be effective. That’s, of course, if everything about those panels is ideal, where the positioning is optimal, the panels are of a standard rating, and the location gets adequate sunlight year round.
A quick way to determine how many panels a roof can support
If you’re working with a client who needs answers fast, there’s a quick way to get an estimate of how many panels a roof can support. Most roofs will need a “solar panel setback” for safety. This setback is the open space around the edge of the array and the edge of the roof. This setback varies from state to state. Generally, the setback will take up 25 percent of the usable space on the roof.
So if you want to get a sense of how many panels a roof can support, multiply the square footage of the roof by .75. Take that number, and divide it by 17.5, which is the average square footage of one solar panel. The resulting number is how many solar panels you can fit on a roof.
There are a lot of factors that go into solar panel arrangement and installation. Fortunately, professional installation firms will help hash out the precise number and type of panels that will work best for your client.
Your career in solar sales starts here
Looking for an illuminating new career? Why not a job in solar energy? Palmetto is hiring new sales consultants to join our team of Alchemists. Great pay, a relaxed work schedule, and opportunities around the country make it a great fit for people with all different backgrounds.