When thinking about a solar energy installation, one of the first questions people ask is, “how many solar panels do I need to power my home?” The purpose of this article isn’t necessarily to give you the definitive answer but to get you closer to one. There isn’t any one calculation that you can use as a universal shortcut.
How many solar panels you need depends on how much energy you use and how much sun is in your location. The size of your home, the amount of energy you use, and your budget will all play a role in determining how many solar panels are necessary. For example, the average home in the San Francisco Bay Area uses 18-20 solar panels. Small and energy-efficient homes use fewer panels, and huge homes with lots of electrical appliances need a lot more.
Sizing a solar panel system
To make informed decisions about the size of the solar panel system that will work best for you, you must first identify your unique needs. One size doesn’t fit all with solar panels. The process can be overwhelming, but experienced solar professionals can help you find the right solar panel set up for you.
How can I determine how many solar panels I need?
For many people, deciding how many solar panels to install can feel overwhelming. If you want to go solar yourself, choosing the correct number of solar panels requires balancing several factors.
Does your home get full sun, or might your roof be shaded? What size is your home, and how energy-efficient is it? How much sun falls on your property every day? How much power do you need? What kind of roof do you have? How much can you afford to spend? How large are your windows? What type of insulation is in your attic? How many solar panels can even fit on your roof?
The right balance depends on these variables and more!
How much roof space do I need for solar panels?
The average American home has around 2500 square feet of roof space. This can be divided into multiple areas, including the attic, the crawl space, and the garage. Roof space is often needed for other considerations, such as skylights or vents, which must be taken into account before deciding to install solar panels. People who want to install solar panels should consider their goals for energy independence, how much money they are willing to spend, and their neighborhood’s regulations.
How does the sun’s energy power my house?
The sun is a major source of energy on Earth. It provides light, heat, and power to everything on our planet. Solar power works by using the sun’s energy to create electricity. Solar panels collect sunlight and turn it into usable electricity.
A photovoltaic (PV) system comprises one or more PV modules linked in a series known as an array. A typical PV module is made up of 60-120 photovoltaic solar cells, and the cells convert into electricity the sunlight. Photovoltaic systems are exceptionally modular because they are built with individual, linked PV modules (the solar panels), allowing for easy transportation and installation and easy expansion if power requirements increase.
Inverters are required in grid-connected (or “grid-tied”) PV systems to convert the direct current (DC) generated by the PV modules into alternating current (AC) for use in your house. Excess power generated but not immediately used can be “sold” back to the utility in exchange for a credit to be used when sunlight is unavailable (this is known as Net-Metering or Net Energy Metering, NEM).
What Affects the Output of Solar Panels?
The efficiency of a solar panel is determined mainly by its design, all else being equal. As a result, the amount of energy generated per square foot is determined.
How tightly the cells are packed on the solar module, for example, reduces the amount of surface area that is actually being used to produce electricity. As a result, solar panels with tightly packed solar cells produce more energy per square foot than those with space between the cells. A solar module that is tightly packed with cells is often more efficient meaning it provides more power per square foot. But it’s important to know that a high efficiency module does not mean high quality. High efficiency modules are usually more expensive and are used when a roof has limited space to install solar panels.
Besides price, there is a consideration for quality. Quality is important since solar modules need to last for at least 20 years. Work with a reputable solar installation company to select a good quality solar module. If the company has been around for a while, they are probably using high quality equipment.
Will solar panels damage my roof?
A common fear among homeowners is that their roof will leak, degrade, or collapse because of solar panels. In fact, the opposite is true; solar panels protect the portion of the roof they cover from the elements. Typically, solar panels are not actually fastened directly to the roof, but to a railing system that is affixed to the roof. To guard against weather damage, sealants and metal “flashing” coverings are used to eliminate any gaps. And, if ever the roof needs repair, the panels can easily be removed from the rails for access to the roof.
Where do I start?
SolarCraft USA solar panels are an excellent choice for powering your home with renewable energy. We recommend you talk to a solar consultant to help develop a good estimate. Each house is different, as are the needs and habits of individuals. The number of panels you ultimately need will be based on your usage. However, you might find that you can only fit fewer than what the calculation suggests. In this case, we would advise using high efficiency panels that have high enough wattage per square foot to meet your household needs throughout the year. Or, conversely, you might find that you actually have extra space on your roof in which case you can install more solar and convert gas appliances to electric. Keep in mind that these are just general guidelines because actual usage depends on so many variables—when people use their air conditioners, for instance, and when they turn on lights. All things considered, it’s best to have work with a reliable solar company to help you determine the best solar panels for the job and how many to install.