How many solar panels are needed to power a house?

Posted: August 28, 2019 Author: zach
solar panels on house

As solar panels have become more and more popular for residential homes, this has become a common question for most homeowners when talking to their solar representative.   How many panels will I need to power my home?  The answer is a very long one based on many determining factors, which we’ll cover in this article, but for those of you in a hurry, here you go:

One 250watt panel will produce 1kWh for every 4 hours of direct sunlight.

Modern solar panels are roughly 5-6 feet wide and about 3 feet in height.  Your standard panel will be around 17-18 square feet.

With this knowledge, you should be able to roughly estimate how many panels you would need to completely power your home with solar.  To find this number, the first step is to find out how much energy your household consumes on average each year.

How to Find Your Average Electricity Use

If you haven’t saved your electricity bills for the past 12 months, you can probably obtain them by contacting your electric company or viewing past statements on its website. It is important to look an entire year’s worth of data to account for the large variation in electricity usage between the summer and winter months. The most important number on your bill that you’ll have to know is the kilowatt-hours your household consumed each month. Most electrical companies may abbreviate kilowatt-hours at kWh.

After locating this figure on the past 12 electric bills, add the numbers together and divide by 12. This will give you the average kWh usage per month of your house. Keep in mind that your figure could be very different from a friend also interested in installing solar panels. It all depends on the square footage of your house, the number of appliances you use and their efficiency, and how many people live in the home and contribute to energy consumption. The average kWh in 2016 was 897 per month according to the United States Energy Information Administration.

How to Determine How Many kWh Your Solar Panels Can Produce on Your House

The biggest determining factor in answering this question is the amount of direct sunlight that typically hits your roof each day. Obviously, some locations are sunnier than others. However, you can still benefit from solar panels if you live in a cold or rainy climate. It will simply require you to install a larger solar panel system on your home. Another option for those who don’t have the good fortune to live in a sunny climate is to choose and install more efficient solar panels.

A household that consumes the average amount of kWh per month would use approximately 30 solar panels for the entire home.  It can be as many as 70 solar panels for homes that use more than twice that amount. This is assuming the use of a standard efficiency solar panel.

Purchasing low or high-efficiency panels can change the total number that you need dramatically. When shopping for new solar panels, keep in mind that those marked monocrystalline photovoltaic (PV) are typically the most efficient. Polycrystalline panels cost less but offer lower efficiency. They also take up more space but can be a good option if you must stick to a specific budget.

Other Considerations About Solar Panels

Installing a complete solar panel system can be costly. If you’re looking to reap the benefits of reduced energy usage but don’t have the funds for a full system right now, you can save up to 50 percent by installing a smaller system and enrolling in a net metering program. With a net metering program, you get credits for the energy you generated but didn’t use because you were on vacation or gone from home for an extended period. This can still decrease your energy bill by as much as 50 percent.

If you have additional questions about installing a solar power system, please don’t hesitate to reach out to us at