How Many Solar Panels Will I Need?

How many panels (also known as solar modules) will I need for a 1,200 sq. ft. home? At Eagle Point Solar we are often asked this question when people first begin to explore solar as a means to producing their own renewable, sustainable, clean electricity. While searching the internet you can find averages determined by the square footage of a home, however, these averages do not take into consideration your personal energy consumption habits. There are many more factors to be considered than just the size of your home to determine the number of solar panels you need. You and your neighbor could have identical homes but very different electric bills. One size does not fit all. Your neighbor could set their air conditioning five degrees lower than you and own an electric vehicle causing them to have a much higher monthly electric bill. To meet your goals and make the most of your solar investment you want to work with a reputable and experienced solar installer who will design and engineer a solar energy system to meet your existing and/or future energy consumption needs. 

How Many Solar Panels Will I Need?

The first step in determining the number of solar panels you will need is by answering one question, “What is your goal for adding solar?” For many people, the answer is to maximize their return on investment, minimize their carbon footprint or save as much money as possible off of their electric bill. 

The next step is to collect the last 12 months of your electric bills and provide these bills to your solar company. An experienced solar company will examine the total number of kilowatt-hours you consume each month to determine your electricity consumption habits. The annual number of kilowatt-hours you consume will provide the foundation for the number of panels you will need.

Additional considerations such as the future use of electric appliances, a hot tub, LED lighting, electric vehicle, four seasons room, etc. can also directly affect the number of solar panels factored into your array during the design and engineering process.

Can Panel Size Effect Panel Quantity?

There is no standard solar panel. The output size across the industry varies greatly. They come in a variety of wattages and dimensions. As with any technology, as time goes on, advancements in manufacturing, materials, and product design will continue to improve efficiency and output. Currently, solar panels range in output ratings of 375–450 watts. Nearly two decades ago, when solar panels began mass production and distribution, panel wattage was around 150–200 watts. Working with an experienced solar company can help you maximize your investment by providing the best technology to fit your energy consumption needs. 

How Does Shading Effect the Number of Panels I Need?

If the area where your solar array will be installed receives a percentage of shade, there are a few options to remedy the shading or loss of production from this occurrence. Ideally, the best option is to trim any trees which may be causing the shading issue or relocate the solar array to an area with less shade. If neither of these solutions is an option, additional panels can be added to your array to offset the percentage of solar production loss caused by shading. A professional solar company can determine through specialized software the percentage of solar production lost to shade and further analyze the number of solar panels needing to be added to the system to make up for the lost energy production. Thus, helping you reach your solar energy goals.

How Many Panels Will I Need If My Roof Does Not Face South?

While south-facing roofs are typically the best choice for maximum solar production, a southeast or southwest-facing roof is still a great alternative for prolonged exposure to the sun. Additionally, east and west-facing roofs can also be considered if south-facing exposure is not available or is limited on space. Much like the ability to analyze shading effects, specialized industry software is very helpful in determining the differences in solar energy production from various locations on your property. This software further aids in the calculation of the number of solar panels needing to be added to your system to offset the difference in location due to reduced sun exposure. 

In Conclusion

While it seems like an easy question to answer in the beginning, determining the number of solar panels for your array quickly becomes a puzzle of multiple degrees of complexity. Be wary of anyone assessing your site and determining the number of panels you need using a notepad and cell phone calculator. If you are considering solar, contact a reputable installer who has completed hundreds (if not thousands) of builds and is supported by a professional team of designers, engineers, electricians, and construction professionals. Seek out credentials such as a NABCEP (North American Board of Certified Energy Practitioners) certification, along with any further related degrees or references to support their experience and client satisfaction ratings.