Factors to Consider
There are four determining factors to consider when deciding how many solar panels you need.
- The average amount of sunlight in your area. There’s a large difference in average sunlight hours in Boca Raton versus Atlanta, for instance.
- The amount of energy the system you’re purchasing can produce.
- The direction your roof is facing. This can be a determining factor in how much sunlight per day these system will be receiving.
- The amount of energy your home uses. As mentioned, this can be found on your most recent electric bills, and is measured in kWh.
Once you’ve collected the data for these four factors, and with weather conditions and average sunlight in mind. You can start to get a better picture of how many solar panels your home needs.
Calculating Your Solar Needs
Let’s take a look at an example of an average home energy use. See how that relates to solar panels.
Without taking geographical factors into account, a home that produces 8,300 kWh using a 7 kW solar system in a decently sunny location would need roughly 25 solar panels in order to offset the home’s energy consumption.
For a home in a similar locale that uses much more energy, a 14,000 kWh usage, with a 10 kW solar system, they would need more solar panels and be on the higher side of average with 36 solar panels.
Translating Solar Panels to Roof Space
Understanding the roof space you need to adequately equip your solar panels can vary on a number of factors as well. One of the main factors is whether you’re using low, medium, or high efficiency panels for your home. These three measures calculate how good your solar panels are at absorbing and converting solar energy. With higher efficiency panels, you’ll need less of them to power your home. Lower efficiency panels can be more cost-efficient but you may need to purchase more and therefore have more roof space.
As an example, if you had a 10 kw solar system with low efficiency solar panels, you’d need roughly 625 square footage of roof space. Upgrading to high efficiency panels will cut that down to 455 square footage. For those with less roof space available, high efficiency panels may be the best option.