The exact number of solar panels needed to power your home will largely depend on four key factors:
- Average energy usage
- Peak sunlight hours in your area
- Power output and efficiency of your solar panels
- Structural characteristics of your roof
The most accurate estimate will come from a professional installer who can evaluate all the pertinent information, calculate the optimal number of solar panels needed, and recommend an appropriate solar energy system to meet your needs. Now let’s consider the details of those four factors one-at-at-time.
1. Average Energy Consumption
Refer to your utility bills to find information about your average electricity usage. Your usage may be shown in the form of kilowatt hours (kWh) used over a given period, such as 30 days, or calculated based on the beginning and ending meter readings taken each month. Whatever the number, your total monthly usage can be divided out to tally average daily and hourly energy requirements.
2. Climate & Hours of Sunlight in Your Area
The number of peak sunlight hours for your location will impact the amount of energy you can expect a rooftop solar-electric generator to produce, and therefore the number of solar panels it will take to produce your daily and monthly average demand. For instance, a home that is located in a mostly sunny area will generally need fewer solar panels than a home that is located in a predominantly cloudy or rainy area.
Taking factors one and two into consideration, the amount of energy you’ll need your solar panels to produce each hour can be calculated as follows:
- Calculate your average hourly energy demand, then add a 25 percent cushion to allow for weather variances that can affect the amount of sunlight hitting your solar panels.
- Multiply by 1,000 to get your average hourly wattage requirement.
- Divide by the number of daily peak sunlight hours in your area (there are official resources like Google’s Project Sunroof, that provide average sunlight information for each state and major city in the U.S.).
3. Solar Panel Efficiency
The productivity of a solar panel can vary based on its technology, design, size, and position on a roof. In the northern hemisphere, optimal solar panel positioning is south-facing, tilted at a 45-degree angle, and out from under any possible shading. Opting for higher-efficiency panels will yield more output (wattage) with fewer panels.
4. Roof Characteristics
A professional installer can assess the architecture of your roof, including its angle relative to the sun and other factors, to determine the best arrangement and the ideal number of panels to reliably match your daily energy demand. For instance, if your home’s usable roof area is limited or partially shaded, it may be necessary to install several small panels rather than a few large ones to create optimum efficiency.
The Blue Raven Advantage
As you continue to learn about the advantages of solar energy, remember the number of solar panels you’ll need is just one aspect to consider. You’ll also want to give some thought to your solar panel options and preferences, including those related to technology, appearance, warranty, and cost. And, perhaps most importantly, you’ll want to work with an experienced solar installer to help navigate the process and provide a high-quality installation that will deliver the benefits of going solar right away.
Unsurprisingly, that's basically a summary of the Blue Raven Solar mission.
At Blue Raven Solar, we’re proud to use mono-crystalline, Tier-1, black-on-black solar panels in all residential installations. All our installations yield top performance, premium looks, and a 25-year manufacturer's warranty on equipment. We custom-design rooftop solar energy systems for each individual customer with a goal to produce the targeted amount of clean energy to save customers money and increase the value of their property.
And did you know, to make solar energy as dependable as the morning sun, Blue Raven Solar offers customers a two-year productivity guarantee? Here’s how it works:
We check in with our customers to audit the production of their solar array after a year, and then again two years after installation. If any of our solar energy systems are found to produce less than original estimates after two years, we update them with more panels free of charge. To learn more about that, go here.