Updated: Jan 14, 2022
Many people ask how many solar panels it will take to power their home. It seems like an easy question, but there are variables. Those include:
1. The type of solar panel used — Different brands of solar panels collect different amounts of sunlight and produce different amounts of usable energy. You should always ask solar installers what type of solar panels they use and how much energy each panel can collect.
2. The amount of energy your home requires — The amount of energy your house requires is a stripped-back version of energy usage. It is the bare minimum amount of energy needed to run the refrigerator, lights, and other essential items such as a water heater. The amount of energy that your home needs to run is the starting point for answering the question, "how many solar panels do I need to power my home."
3. The amount of energy you use each month — Your power provider should tell you the amount of energy you use each month. Some bills will have a graph showing usage month by month, if not you can compile your bills and calculate usage or ask your utility company for your energy usage over the year.
4. How your system is set up — Off-grid vs. connected to the grid.
Is Your Home Connected to the Grid?
Connecting to the grid means that you use the energy your solar array creates, and if that is not enough, you draw power from the grid. There are some benefits of remaining connected to the grid. On days when your solar array produces more energy than you use, it goes back into the grid, and depending on local and state regulations, you may receive solar credits to help pay for energy you use from the grid. Be sure to check with your power provider about solar credits and how they work in your area.
When your home is off-grid, the number of solar panels you need to power your home is more critical. When your home remains connected to the grid, you have more leeway in determining the amount of energy your solar array needs to create. However, during times of crisis, and we witnessed that recently in Texas when their grid failed, and millions of people were without the power to heat their homes or cook meals. That is a good reminder that the grid is not always reliable. These are part of the variables you need to know to make an informed decision about how many solar panels your home needs.
Let's Talk Numbers
In 2019, the average US home used 10,649 kWh per year or 877 kWh per month, according to the US Energy Information Administration. The average solar panel collects between 320-350 watts of energy per hour of optimal sunlight. In Indiana, your home usually receives around 4.22 hours of direct sun, so the solar panel would produce a maximum of 1,477 Watt-hours at 350 Watts of production or 1.5 kWh. A 320 Watt solar module receiving 4.22 days of direct sunlight would produce 1.4 kWh. If your home uses 30 kWh of electricity per day, then you would need about (20) 350-Watt solar modules. You would need about (22) 320-Watt solar modules. That information is assuming every day; your home has at least 3.5 hours of direct sunlight.
In raw numbers to produce 30 kWh of energy at 4.22 hours of direct sunlight every day. You would need:
• 20 solar panels at 350 watts per one hour of sunlight
• 22 solar panels at 320 watts per one hour of sunlight
The Variables in Energy Production
The sun's position changes seasonally, and that can impact the number of hours of direct sunlight your system receives. Maintenance is also a consideration as dirt or debris on the solar panels decreases the amount of sunlight that strikes the solar panel. Trees, clouds, and other transient objects also impact how much solar radiation hits the panel. All these things affect the total amount of energy your system can create.
So, how many solar panels do you need to power your home? It's a bigger question than it seems to be. If you are looking for a personalized answer to your solar situation, give us a call. We work with you to provide solutions that are specific to your home energy needs.