How to calculate the number of solar panels you need is important knowledge to have when going solar. Beware anyone who offers you a cookie cutter solar solution! A good solar company will customize a solar panel installation to the home and its energy needs.
One way to make sure you are getting the amount of solar panel performance you expect is to understand solar installation design. Let’s take a look at all of the factors that go into a quality, customized solar installation.
How much energy do you use in a year?
The first thing we look at when designing a solar system is how much energy your home uses. Our goal is to offset 100% of your power needs so that when you get your energy bill, you simply pay the basic customer charge (around $10 to $15/month at the time of the writing of this post).
You can get an estimate of your energy needs by looking at your utility bill. In the details section, there is a summary of how many kilowatt-hours (kWh) you have used for the time period of that statement. To understand your annual usage, look over 12 consecutive statements in your online bill portal, add that kWh usage together, and divide by twelve. That’s your average usage, and that’s what your solar system needs to produce in order to reach 100% offset. Calculating your energy needs this way is much more accurate than simply looking at your highest and lowest bills.
Which direction does your roof face?
In Florida, we are called the Sunshine State for good reason! We receive so much clean, green sunshine that solar panels make sense anywhere but on the north-facing parts of your roof. South-facing areas make the most energy due to having sun exposure all day, but west and east are both good options as well, making 85% to 90% percent of what a south-facing roof can do.
When we design a system for you, our consultants pull up your home on satellite in a special solar design software that predicts solar production for different types of panels based on your roof’s orientation and pitch. Most Florida homes have lower pitches (around 22 to 24 degrees), which are great for solar. If you have a higher pitched roof, say 30 degrees, your roof is less sky-facing and therefore less sun-facing. The software takes it all into account, and with a little experimentation, an experienced solar consultant can maximize your roof space to make the highest amount of energy at the lowest cost.
How much shading is on your roof from trees?
Shading is a real solar-killer and can reduce solar energy production by as much as 20 to 40 percent. If you have a lot of trees shading your roof, your solar consultant will likely recommend that you have them removed.
If you are in love with your trees (and we get that), our solar design software can be used to calculate the number of solar panels you need with and without shading so you can see whether trimming those branches is worth your while. Sometimes using a different area of the roof, a smaller or larger panel, or a different panel orientation can make a difference to avoid panels being shaded.
Does your utility offer net metering?
We have an entire blog post on net metering that explains how it works, but in a nutshell, net metering is the credit/debit system a utility uses to keep track of how much energy you use versus how much you make. If your utility offers this service, it allows you to make more of the power you use because you overproduce during the day and then use up your “credits” at night, when your panels aren’t making electricity.
Your solar consultant will take into account your utility’s net metering policy when sizing your system. If your utility doesn’t offer net metering, a battery backup system is an option. If the net metering policy isn’t great, don’t worry. A good solar consultant can tweak your system to compensate for that so you can go solar with confidence at the best bang for your buck.
How do rainy days and cloudy days affect solar?
Our solar design software takes into account normal weather patterns for your area, including rainy days, cloudy days, storms, etc. When we do a design for you, rest assured that the design is not based on an unrealistic assumption of sunny weather 52 weeks and 365 days a year. All those cloudy, rainy, hurricane days are baked in, too!
The best solar companies in Florida
If you are entertaining multiple solar quotes, it’s a good idea to know how much energy you use and make sure the solar solution being proposed to you meets those needs. Many solar companies will overpromise and under-deliver, but by the time you realize this, it’s too late! The glass is on your roof and you are left holding the electric bill.
Protect yourself by ensuring you understand your kilowatt-hour usage from your energy bill and by choosing a company who invests in sophisticated custom solar design software to calculate the number of solar panels you need and ensure your system’s production meets your expectations. A “cheap” solar solution usually means less power produced per dollar. Don’t be fooled!
At Coronado, we install solar PV systems across the state of Florida, and we’d love to do a design for your home, for free, no strings attached! Just follow this link and click “Request a Quote.” We look forward to hearing from you!