Solar Panel Array Size Calculator
Check Your Monthly Electric Bill
First, look at your electric bill to find your total energy usage for a month, usually provided in kWh. Divide that number by the number of days in the month (typically 30) to calculate your average daily consumption.
For example, if your bill shows 900 kWh for the month, your daily average would be 900 kWh ÷ 30 days = 30 kWh
Alternatively, if you have a smart meter or energy monitor installed, you can track your usage over several days to get a more accurate average.
Check Your House Appliances and Usage Hour
Another method is to add up the energy usage of all your appliances. Check the wattage of each device and estimate how many hours per day it runs. Convert each device's consumption from watts to kWh by multiplying the wattage by the hours of use and then dividing by 1000. You can use our solar calculator quickly to setup appliances and estimate your monthly kW consumption and then the daily consumption.
How Many Solar Panel To Power My House
Assume you have a 400W panel, but due to inefficiencies the actual output is 25% lower than 400W, which equals 300W effective. With 4 hours of effective sunlight, one panel produces:
300W × 4 hours = 1,200 Wh or 1.2 kWh per day.
If your house uses 30 kWh per day, then you need:
30 kWh ÷ 1.2 kWh per panel ≈ 25 panels.
It's recommended to choose a system with at least a 25% higher output capacity than your average consumption to account for inefficiencies due to weather and other factors. Solar panel efficiency varies by type—monocrystalline panels are the most efficient. Weather and climate also impact efficiency, requiring potentially larger systems or battery backups for off-grid living.
Inverter Size Calculator
After determining the solar panel array size to match your average house daily power consumption, the next step to calculate inverter size to match the solar panel array. Use our inverter size calculator to make an estimation.Final Thoughts
Determining the optimal number of solar panels for your home is crucial for designing an efficient, cost-effective solar system.
As energy prices continue to rise and sustainability becomes increasingly important, having an accurate solar panel count can lead to significant long-term savings while reducing your carbon footprint.
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