With electricity prices rising in all regions and a growing emphasis on renewable energy, more and more homeowners are willing to install solar panels in order to reduce their electricity bills and do their part to reduce their carbon footprint. For a 1500ft² (140m2) home, solar panels offer a good option for such a large home to realize a reduction in dependence on the grid and savings in household expenses. So, in this article, we’ll give you an overview of how many solar panels are needed for a 1500ft² (140m2) home and related issues.

The only thing we know about a 1500ft² house is the size of the house, but if we want to calculate how many solar panels are needed for such a house, this data is not enough. We come to need to know the type of roof of the house and the power of the solar panels you want to install. Among the types of roofs available nowadays, the main types of houses that are more suitable for installing solar panels are pitched color steel or tile roofs and horizontal concrete roofs. Below we categorize the different roof types to calculate the number of solar panels.

Sloped steel or tile roof

For sloped steel or tile roofs, solar panels are typically placed flat on the roof by the installer, using adhesives or parallel framing to secure the panels directly to the roof.

Knowing the total power of the solar panels that can be installed on your roof: When we know the size of the house, we don’t know the power of the solar system directly, but there is a relationship between the power of the solar system and the size of the house. In fact, there is a relationship between the power of the solar system and the size of the house. You can use the following formula to know the power of the solar system.

The total power of solar panels that can be installed on your roof = 210W/m×roof area

For a house of 1500ft² (140 square meters), the power of the solar system you can install is 210W/m*140㎡ = 29,400W.

Determine the power of the solar panels you want to install: the power of the solar panels is related to the photoelectric conversion efficiency of solar energy. When the power of the solar panel is higher, the more electricity the solar panel can produce. However, for high power solar panels, they may also be a bit larger and you need to be sure that you are not going to have the power of the solar panels cause them to go beyond the boundaries of your roof. In addition, the larger power solar panels will also be a little bit more expensive, and you will also have to budget for the cost if you want to buy larger power solar panels. In addition to that, you have to consider the weight of the solar panels, the impact of the solar panels on the roof.

Number of solar panels = total power of solar panels that can be installed on your roof / power of solar panels

If you decide to install 450W solar panels, the number of solar panels you need to buy is 29,400/450 ≈ 66.

To summarize: If you have a house with a 1500ft² (140m2) sloping color steel or tile roof, you can install a solar system with a power of 29,400W, and you will need to buy 66 pieces of 450W solar panels.

Horizontal Concrete Roof

For horizontal concrete roofs, a typical installer will use fixed brackets and precast concrete to secure the solar panels to the roof at an angle.

Knowing the power of solar system that can be installed on your roof: For the calculation of the number of solar panels that can be installed on a horizontal concrete roof, it is similar to the calculation of a tilted color steel or shingle roof, except that the total power of the solar panels that can be installed on the roof is not the same, and you need to use the following formula if your roof is a horizontal concrete roof.

Total power of solar panels that can be installed = 150W/m x roof area

Then the power of the solar system you can install is 150W/m*140 square meters = 21000W

After you have calculated the total power of the solar panels that can be installed on a horizontal concrete roof, the rest of the steps are the same as the first calculation, you can continue to calculate in the same way as above to get the result.

If you choose to install the power of the solar panels or 450W, then the number of solar panels required is 21000W/450W ≈ 47 pieces!

Summary: If you have a house with a 1500ft² (140m2) roof, you can install a solar system with a power of 21,000W and you will need to buy 47 units 450W solar panels.

Conclusion:

For the number of solar panels needed for a 1500ft² house, the calculations we have provided you with will give you an approximate estimate of how many solar panels can be installed on your roof, but the actual number of panels may change depending on the orientation of your roof and the energy usage of your home.