How Many Solar Panels Do I Need?

The number of solar panels you need is an important factor in deciding your system’s design, price, and efficiency. There is no one number that’s perfect for everyone. The number of solar panels necessary for a properly operating system depends on the size of the house, the amount of sun available, the household’s energy needs, and many other factors. Due to the complexity of the decision, most solar companies offer free quotes either online or after an in-person inspection to advise you on the number of solar panels you’ll need.

Assessing Your Goals

The number of solar panels that’s best for you depends on what your goals are for switching to solar. You may prioritize reducing your home’s carbon footprint, or you may be more interested in maximizing your return on investment. In most cases, people want to save as much money on their energy bills as possible while helping the environment. The goals you have for your system will help experts assess how many solar panels are right for your needs.

Household Energy Requirements

The next question to ask yourself is: What are my household energy requirements? Different households use different averages of energy. The typical household uses about one kilowatt of energy per hour (kWh). However, many things can increase this average. Owning a hot tub, for example, expends greater amounts of energy, as does using the computer for long hours at a time. Using more than one large appliance or keeping them running will also increase energy usage. Don’t forget to factor in air conditioning use during the summer months.

Sunlight Availability in Your Area

Keep in mind that solar panels won’t operate at maximum efficiency 100% of the time. Poor weather conditions, cloudy skies, and snowfall can all affect your panels’ energy output. Locations that see a large amount of sunshine, such as California, can most likely get away with using fewer solar panels. The peak sunlight hours where your home is located impacts the energy your system will produce. This doesn’t mean that someone living where there is lots of cloud cover will get a less efficient system – but it does mean he or she would need more solar panels.

Use the Renewable Resource Data Center’s maps to estimate your daily kWh requirements based on your city and state.

Panel Quality

There are a few different types of solar panels available, some that are higher quality and thus more efficient than others. Monocrystalline solar panels use the highest-quality silicon, and are the most efficient panels on the market. Other types use different technologies. Weigh the pros and cons of each type, including the fluctuating prices, before deciding which is right for your home. Depending on the quality and efficiency of your panels, the number you will need varies.

Divide the hourly energy your home requires by your specific type of solar panels’ wattage to decide the total number of panels you need.

Roof Space

One of the most general things you’ll need to consider is how many solar panels your roof can fit, and how much weight it can take. The average solar panel today is about 15 square feet, or three feet by five feet. Take your roof’s available square footage and divide it by 15 for an estimate as to how many solar panels will fit. Each panel produces an average of 190 watts of energy, or 0.19 kilowatts. This will help you understand about how many panels you’ll need to fulfill your household energy needs. Keep in mind these numbers will vary depending on the exact size and energy capabilities of the panels you choose.

Knowing exactly how many solar panels your home or business needs for optimal energy output and cost savings is difficult without consulting a professional solar company. Where you live, how much energy you plan on using, and the size of your roof are all factors an expert must take into consideration to calculate the ideal number of solar panels for you.