HOW MANY SOLAR PANELS I NEED?

Determining the number of solar panels needed for your home depends on several factors, including your energy consumption, the size and efficiency of the panels, the amount of sunlight your location receives, and the available roof space. To start, you need to calculate your average daily electricity usage in kilowatt-hours (kWh) by reviewing your utility bills. Next, consider the wattage of the solar panels you intend to use, which typically ranges from 250 to 400 watts per panel. Additionally, account for the average peak sunlight hours your area receives per day. For instance, if you use 30 kWh per day and your location gets about 5 peak sunlight hours daily, you would need a system that produces 6 kW per day. Using 300-watt panels, you would need around 20 panels (6000 watts / 300 watts per panel). However, these estimates can vary, and a professional solar installer can provide a more precise assessment based on your specific circumstances.

Average annual electricity use

On average, an American household uses approximately 11,000 kilowatt-hours of electricity annually. If you are particularly energy-conscious and reside in a home smaller than the average 2,000 square feet, your consumption will be lower. Conversely, if you live in a larger home and frequently use multiple energy-intensive appliances, your electricity usage will be higher.

A high-quality solar panel might generate 290 watts. If it receives an average of 4 hours of direct sunlight per day, it would produce 1,160 watt-hours, or 1.16 kilowatt-hours, each day. Annually, this would total approximately 423 kilowatt-hours.

Calculation

To determine the number of solar panels needed for your home, divide your annual electricity consumption in kilowatt-hours by the yearly output of one panel. This calculation will show you how many panels are necessary to meet your energy needs.

For instance:

11,000 kilowatt-hours needed annually ÷ 423 kilowatt-hours per panel = 26 panels required

It’s important to note that solar energy experts recommend slightly oversizing your system to account for cloudy weather and other potential inefficiencies.