How Many Solar Panels Do You Need?

Are you thinking about going solar? It’s a great feeling, knowing that you’re helping the planet and saving money at the same time. Now, the next question is: How many solar panels do you need for your home?

How many solar panels does the average house need? How many solar panels do I need for a 3-bedroom house? How many solar panels do I need for a 2000 sq. ft. home? These are all common questions for an aspiring solar homeowner. Determining how many solar panels you’ll need for your home requires first knowing what your goals are.

To calculate how many solar panels you need, you need to know:

Most people want to save money while minimizing their environmental impact.

Your average energy requirements

Your current energy use in watts

The climate and amount sunlight in your area

The efficiency of the solar panels you’re considering

The physical size of the solar panels you’re considering

How much solar power will you need?

To determine your home’s average energy requirements, look at past utility bills. You can calculate how many solar panels you need by multiplying your household’s hourly energy requirement by the peak sunlight hours for your area and dividing that by a panel’s wattage. Use a low-wattage (150 W) and high-wattage (370 W) example to establish a range (ex: 17-42 panels to generate 11,000 kWh/year). Note that the size of your roof and how much sunlight your roof gets are factors as well.

Total Electricity Consumption (KWh)

The number of solar panels you need for your home depends on a few factors, the most important of which is your monthly electricity consumption.

Determining your home’s total electricity consumption is not as difficult as it may seem.

Look at past electricity bills and find the total kilowatt hours (kWh) used over a year (annual energy usage). Then divide total kilowatt-hours by 12 to find your home’s average monthly electricity usage.

Knowing your home’s average energy usage is essential when calculating the number of solar panels you need. That number will tell you how large of a solar energy system you’ll need to generate the amount of electricity you use each month.

Remember that you’ll also need to account for shading and other factors that may affect your system’s performance.

To get a more accurate estimate, it’s always best to have a solar installer come out and do a site survey. But using this simple calculation will give you a general idea of what you need.

How many hours of sunlight can you expect in your area?

The peak sunlight hours for your particular location will have a direct impact on the energy you can expect your home solar system to produce. For example, if you live in Phoenix you can expect to have a greater number of peak sunlight hours than if you lived in Seattle. That doesn’t mean a Seattle homeowner can’t go solar; it just means the homeowner would need more panels.