How Many Solar Panels Do I Need to Become Energy Independent?

More and more people are installing solar panels in order to reduce the cost of their electric bill and reduce their carbon footprint. It’s becoming very common to see these panels converting sunlight to electricity on the roofs of both businesses and residential homes. This technology has been around for quite some time, but now that it’s easily available and affordable for the public, many questions have been arising.

‘How many solar panels do I need’ is a frequent question being asked by many people looking to make the wise investment. In order to become energy independent, some calculations can be made to make an accurate estimate, but keep in mind there isn’t a one solution fits all answer.

Variables.

1. The Amount of Energy You Currently Use.

This variable is completely dependent and controlled by your personal use. Frequent use of electric appliances such as hot water heaters, heating systems, and stoves are all examples of things that’ll increase the amount of electricity you need. Simply put, the more electricity you use, the more solar panels you’ll need

2. The Amount of Solar Radiation.

Unlike personal energy usage, this variable is much harder to manipulate. Other than choosing where to live, this is pretty much out of your control. It shouldn’t be a surprise that the amount of solar radiation is different depending on where you’re geographically located. For example, the use of solar energy in the United States is higher in a state like New Mexico, since a roof there will get more solar exposure than a roof located somewhere in the Northeast. The more radiation your roof is exposed to, the fewer panels you’ll need.

Doing the Math.

One important factor to understand is the efficiency of solar cells. Current photovoltaic solar technology converts around 15% of sunlight absorbed to actual usable electricity. With this information we can apply some math.

Let’s revert back to the example of a home in New Mexico. The average annual solar insolation there is around 6 kilowatts per meters squared per day. At the 15% efficiency rate, you will need 53 square meters, or 574 square feet of PV solar panels. For states in the Northeast, the average annual solar insolation is around 4 kilowatts per meters squared per day. This means that for a home of the same size in New York, you’ll need 80 square meters, or 861 square feet of PV solar panels.

Although these numbers are good references, general averages can also be applied as long you remember that these this average can vary. On that note, solar home PV electric systems usually require 20+ panels, and each panel is around $1000 value installed. However, depending on your location and energy use, this average could decrease.

If you want to know how many panels you’ll actually need on your roof contact us for a free quote from a Superior Solar Energy Specialist. We conduct both a preliminary analysis using satellite imagery and a full analysis which is conducted on location. Both evaluations are FREE. If solar is a good fit for your home or business, we'll provide you with a clear and clean quote, as well as current financing and leasing options.