While there are many factors that affect the amount of energy a solar panel can produce, you can expect a typical single solar panel in the United States to generate about 2 kWh per day, which saves an average of $0.36 on electricity costs per day.
How Can I Figure Out The Output Of A Solar Panel
It is difficult to estimate how much electricity your solar panel system would produce because each one is unique. You can get a general idea and an estimate of how much money you could save by using this helpful calculator provided by the Centre for Alternative Technology.
You can also use a few general benchmarks to determine the potential output of your system.
1. Solar Panel Output Per Day
Utilize the following formula to determine the amount of electricity, expressed in kilowatt-hours (kWh), that your solar panels would generate each day:
Size of one solar panel (in square meters) x 1,000
That figure x Efficiency of one solar panel (percentage as a decimal)
That figure x Number of sun hours in your area each day
Divide by 1,000
Less on efficiency is provided below.
Use this calculator to determine how many sun hours are expected in your area.
Example
- 1.6 square meters are occupied by the panel:
- 6 x 1,000 = 1,600
- 20% energy-saving panel:
- 1,600 x 0.2 = 320
- Your region receives 4.5 hours of sunlight each day*:
- 320 x 4.5 = 1,440
- Divide by 1,000:
- 1,440 ÷ 1,000 = 1.44 kWh per day
*The number of sun hours varies significantly throughout the year (4.5 hours is an estimate for July), and will be considerably lower in the winter months.
2. Solar Panel Output Per Month
Calculate the daily amount and multiply it by 30 to get the monthly total:
- 1.44 x 30 = 43.2 kWh per month
3. Solar Panel Output Per Square Metre
4 kW solar panel systems are the most widely used in domestic settings. This has 16 panels, each of which contains the following information:
- around 1.6 square meters (m2) in size
- rated to produce roughly 265 watts (W) of power (in ideal conditions)
Utilize the following formula to determine the output per square meter:
Number of panels x Capacity of the solar panel system
Capacity ÷ Total size of the system (number of panels x size of one panel)
Example
- 16 panels of 265 W each:
- 16 x 265 = a capacity of 4,240 kW
- 16 panels, total, make up the system.6 m2 each)
- 4,240 ÷ 6 = 165 W per m2
How Much Energy Can A Solar Panel System Produce In Its Entirety?
It’s important to know how much energy each solar panel produces, but how much solar power can your roof produce? Let’s calculate the following:
Consider the scenario in our example above, where you have solar panels that are rated at 290 W and receive five hours of direct sunlight on average per day, which is the standard amount of sunlight for most of California.
If you put 30 of those high-end solar panels on your roof, you would have an 8,700 watt, or 8.7 kW solar panel system, near the average system size purchased on the EnergySage Market.
The five hours of direct sunlight we calculated above are multiplied by 8.7 kW, and we get approximately 43.5 kWh of electricity produced per day.
Finally, multiplying 43 will yield a conversion.5 by 365 days in a year, we get approximately 15,800 kWh of electricity produced in a full calendar year from a rooftop array of 30 premium, 290 W solar panels, given that the average annual consumption of electricity in the United States is about 10,600 kWh.
That should be sufficient for the U.S. to use solar energy to power its home.
Due to our estimate of the system’s expected annual solar radiation (or “sun hours”), this cost is probably on the high end for most solar buyers.
What Affects The Amount Of The Energy Do Solar Panels Produce
Panel Characteristics
The panel’s wattage, or power rating, should be your primary concern when it comes to power generation. According to a particular set of laboratory conditions known as Standard Test Conditions (STC), a panel’s wattage indicates how much power it will be able to generate.
The majority of residential solar panels in use today have a power rating of 300 to 370 watts. The higher the wattage of a panel, the more electricity it can produce.
The way a panel is built affects the wattage of the panel. The wattage of a solar panel, for instance, depends on the type of solar cells used.
Due to their ability to produce more electricity than earlier solar cell technologies (specifically polycrystalline solar cells), monocrystalline solar cells are now used in the majority of solar panels.
A solar panel’s capacity to produce energy will also depend on how many solar cells are contained within it. Either 60 or 72 cells are typically present in solar panels. 72-cell panels produce more electricity simply.
Because there are more solar cells, however, they are much larger in size so they’re rarely used for residential solar.
Amount Of Sunlight
Another significant determinant of how much electricity a solar panel will produce is the amount of sunlight that it receives. The solar panel can produce more electricity the more sunlight that is available to it.
Solar panels are tested in a lab environment with 1,000 watts of sunlight per square meter for one hour. This is referred to as a “peak sun hour,” and scientists have calculated how many peak sun hours each place on earth receives each day.
In locations with more peak sun hours, solar panels can generate more electricity.
Other Factors
A lot of other factors affect how much electricity a solar panel will generate. For instance, consider the panel’s temperature: as a solar panel gets hotter, it actually produces less electricity. More information about how temperature affects solar production can be found here.
The panel will produce less electricity if it is in any way covered, such as by a tree’s shade or dust that collects on its surface.
The amount of solar electricity produced will vary even depending on the slope and orientation of your roof. Simply because of how the sun moves across the sky, south-facing roofs are typically able to generate more electricity.
Final Thoughts
You now know how much solar electricity a single solar panel and a whole system can generate.
The best part about installing solar, though, is that it does much more than just allow you to power your house with green energy; it also enables you to save money.
You can avoid paying your utility by using the electricity produced by the solar panels on your roof rather than obtaining it from them and using it instead.