Uploaded July 2024 | Updated September 2026, 1 week ago
š Free Diagrams: cleversolarpower.com/free-diagrams
š My Best-Selling book on Amazon: cleversolarpower.com/off-grid-solar-power-simplified
PV Watts tool: pvwatts.nrel.gov/index.php
Recommended batteries: cleversolarpower.com/go/red and cleversolarpower.com/go/li
In this video, I'm going to show you exactly how to calculate the power output of your solar panels. If you've ever wondered how much power does a solar panel produce per day, especially if you're in a location like Houston, Texas, you're in the right place. With 5kW of solar panels, you can produce up to 15kWh of energy daily. But how do I know this?
I'll introduce you to a powerful tool called PV Watts, which makes solar panel output calculation easy and accurate. Plus, Iāll share a real case from one of my subscribers, Mia, and explain everything step-by-step.
Using PV Watts Tool
Let's calculate the solar power potential in Houston, Texas. First, weāll input the location and system details into the PV Watts tool. This tool covers all locations on Earth and provides precise solar power output estimates.
Location and System Info:
- Search for Houston, Texas, and check the map.
- Note the latitude (30Ā°) for calculating the optimal tilt angle for your solar panels.
- Enter your total solar power in kilowatts (e.g., 0.5kW for 500W or 1kW for 1000W).
- Select 'Standard' for module type and 'Fixed Open Rack' or 'Fixed Roof Mount' for array type, depending on your setup.
- Leave the system losses at default.
Tilt Angle Calculation:
- Use the latitude to determine the tilt angle. the latitude of Houston is 30Ā°.
- For off-grid systems, optimize for winter with the formula: latitude + 10Ā° = 40Ā°.
- For grid-tied systems, optimize for summer: 0.69 Ć latitude + 3.7 = 24.4Ā°.
Advanced Settings:
- Set the azimuth to 180Ā° for south-facing panels in the northern hemisphere or 0Ā° for the southern hemisphere.
- Adjust for bifacial panels if applicable, though the output change is minimal.
Understanding the Results
Once we input all the details, PV Watts provides the expected monthly yields. Hereās a breakdown:
- Monthly Sun Hours: Average sun hours per day for each month.
- Total Energy Harvested: Total energy produced per month.
For example, in January, with 4.23 sun hours per day, a 1kW solar panel array produces approximately 104kWh per month.
Surprising Insights
Did you notice something strange? December has the least sun hours, as expected, but February, with more sun hours, produces less total energy. This is due to February having fewer days.
- December: 98kWh / 31 days = 3.16kWh/day
- February: 93kWh / 28 days = 3.32kWh/day
Practical Example
Letās put this into practice with a real-life example. Eric, a subscriber in Houston, needs to recharge a 15kWh battery daily. We set our location to Houston and optimized the tilt angle for winter. To meet his energy needs in December, the month with the least sun hours, we calculated the solar power required.
Using a 5kW solar array, Eric can produce enough energy to recharge his 15kWh battery. The PV Watts tool shows a monthly production of 487kWh in December, exceeding the required 465kWh. Therefore, a 5kW solar panel installation is sufficient to recharge his battery during the worst time of the year.
Explanation of Sun Hours
Many people ask, "I have 10 hours of sun daily; why do you say I have 5 sun hours?" Hereās why: One sun hour equals 1,000W/mĀ² of solar irradiance. So, 10 hours at 500W/mĀ² equals 5 sun hours. Daylight hours arenāt the same as sun hours.
Understanding STC
The values on the back of the solar panel are under Standard Test Conditions (STC) at 1,000W/mĀ². If the irradiance is only 500W/mĀ², a 100W panel will produce a maximum of 50W under these conditions.
If youāre curious about how much power your solar panels can produce and want to optimize your setup, this video will give you all the insights you need!
š Free Diagrams: cleversolarpower.com/free-diagrams
š My Best-Selling book on Amazon: cleversolarpower.com/off-grid-solar-power-simplified
PV Watts tool: pvwatts.nrel.gov/index.php
Recommended batteries: cleversolarpower.com/go/red and cleversolarpower.com/go/li
In this video, I'm going to show you exactly how to calculate the power output of your solar panels. If you've ever wondered how much power does a solar panel produce per day, especially if you're in a location like Houston, Texas, you're in the right place. With 5kW of solar panels, you can produce up to 15kWh of energy daily. But how do I know this?
I'll introduce you to a powerful tool called PV Watts, which makes solar panel output calculation easy and accurate. Plus, Iāll share a real case from one of my subscribers, Mia, and explain everything step-by-step.
Using PV Watts Tool
Let's calculate the solar power potential in Houston, Texas. First, weāll input the location and system details into the PV Watts tool. This tool covers all locations on Earth and provides precise solar power output estimates.
Location and System Info:
- Search for Houston, Texas, and check the map.
- Note the latitude (30Ā°) for calculating the optimal tilt angle for your solar panels.
- Enter your total solar power in kilowatts (e.g., 0.5kW for 500W or 1kW for 1000W).
- Select 'Standard' for module type and 'Fixed Open Rack' or 'Fixed Roof Mount' for array type, depending on your setup.
- Leave the system losses at default.
Tilt Angle Calculation:
- Use the latitude to determine the tilt angle. the latitude of Houston is 30Ā°.
- For off-grid systems, optimize for winter with the formula: latitude + 10Ā° = 40Ā°.
- For grid-tied systems, optimize for summer: 0.69 Ć latitude + 3.7 = 24.4Ā°.
Advanced Settings:
- Set the azimuth to 180Ā° for south-facing panels in the northern hemisphere or 0Ā° for the southern hemisphere.
- Adjust for bifacial panels if applicable, though the output change is minimal.
Understanding the Results
Once we input all the details, PV Watts provides the expected monthly yields. Hereās a breakdown:
- Monthly Sun Hours: Average sun hours per day for each month.
- Total Energy Harvested: Total energy produced per month.
For example, in January, with 4.23 sun hours per day, a 1kW solar panel array produces approximately 104kWh per month.
Surprising Insights
Did you notice something strange? December has the least sun hours, as expected, but February, with more sun hours, produces less total energy. This is due to February having fewer days.
- December: 98kWh / 31 days = 3.16kWh/day
- February: 93kWh / 28 days = 3.32kWh/day
Practical Example
Letās put this into practice with a real-life example. Eric, a subscriber in Houston, needs to recharge a 15kWh battery daily. We set our location to Houston and optimized the tilt angle for winter. To meet his energy needs in December, the month with the least sun hours, we calculated the solar power required.
Using a 5kW solar array, Eric can produce enough energy to recharge his 15kWh battery. The PV Watts tool shows a monthly production of 487kWh in December, exceeding the required 465kWh. Therefore, a 5kW solar panel installation is sufficient to recharge his battery during the worst time of the year.
Explanation of Sun Hours
Many people ask, "I have 10 hours of sun daily; why do you say I have 5 sun hours?" Hereās why: One sun hour equals 1,000W/mĀ² of solar irradiance. So, 10 hours at 500W/mĀ² equals 5 sun hours. Daylight hours arenāt the same as sun hours.
Understanding STC
The values on the back of the solar panel are under Standard Test Conditions (STC) at 1,000W/mĀ². If the irradiance is only 500W/mĀ², a 100W panel will produce a maximum of 50W under these conditions.
If youāre curious about how much power your solar panels can produce and want to optimize your setup, this video will give you all the insights you need!
