Solar Shade Calculator

Enter your location, number of panels, panel wattage and expected system efficiency to calculate estimated annual production, average daily production, monthly production, peak sun hours and recommended panel tilt angles.

Solar output estimates from historical weather data · for informational use only

Important: This calculator estimates solar yield using location and system information. It does not measure the shadow of individual trees, walls, water tanks, or nearby buildings. For an accurate assessment of shading, the installation site must be physically surveyed.

What does the solar shade calculator show?

The calculator gives you an initial estimate of how your solar system might work in your chosen location.

Your results may include:

•  Estimated annual solar production in kWh
•  Average daily solar output
•  Estimated CO₂ avoidance
•  The most productive month
•  Monthly solar generation
•  Peak sun hours
•  Recommended Monthly Panel Tilt
•  Average annual tilt recommendation

These figures are useful when comparing options before moving on to a detailed design of a solar system.

How to use the solar shade calculator?

1. Enter your location.

Enter your city, address, or other supported map location in Pakistan. Latitude and longitude can also be used where available. Location is important because solar radiation and seasonal sunlight vary across Pakistan.

2. Enter the number of solar panels.

Enter the number of panels you plan to install or have already installed. If you haven’t decided on the number of panels yet, you can use a solar size calculator to estimate the system capacity needed for your electricity consumption.

3. Select your panel wattage.

Choose the rated wattage of your solar panel. You can usually find this figure on the panel’s specification sheet or product label. Using the correct wattage helps create a more relevant estimate for your proposed system.

4. Enter system performance.

Enter the system performance assumption you want to use. When comparing different panel quantities or locations, keep this value consistent so your comparison remains meaningful.

5. Calculate your solar output.

Run the calculation and review both the annual estimate and the monthly generation figures. Solar energy production is not the same throughout the year, so monthly results can give you a clearer picture of seasonal performance.

Understanding your solar calculator results

Annual solar output

Annual yield indicates the approximate amount of electricity your chosen solar setup can generate over the course of a year. This figure is useful for comparing different system configurations, but the actual generation will depend on the conditions at your property.

Average daily solar output

Average daily production converts estimated annual production into a daily average. Your actual daily generation will vary. Cloud cover, temperature, dust, panel orientation, and shading can all affect how much electricity your panels produce on a given day.

The most productive month

This result indicates the month in which the strongest solar output is expected from your selected location and system. For a better understanding of year-round performance, compare this result to the full monthly generation chart.

Monthly solar generation

The monthly forecast shows how much solar energy production is expected to change over the course of the year. This is especially useful for understanding the difference between summer and winter production and comparing expected production with seasonal electricity consumption.

Recommended solar panel tilt

The calculator provides monthly tilt recommendations based on your chosen location, along with annual averages. The theoretical maximum angle may change from month to month, but that does not mean that the roof system needs to be physically adjusted every month.

Most fixed installations also have to take into account the roof structure, available space, drainage, air exposure, maintenance access and mounting requirements.

Does this calculator measure actual roof shading?

No. It uses your location and solar system details to estimate potential solar production. For accurate roof shading analysis, the position, height, and dimensions of nearby obstacles need to be considered as part of a site survey or detailed solar design.

How does shade affect solar panel performance?

Solar panels typically produce the most electricity when they receive direct, unobstructed sunlight. Shadows can shift across a roof as the sun’s position changes throughout the day and throughout the year. A roof that looks perfectly clear at noon may be shaded in the morning or late afternoon.

Common sources of roof shade

These may include:

•  Nearby buildings.
•  Tree
•  Boundary and parapet walls.
•  Water tank on the roof
•  Utility poles.
•  Satellite dishes
•  Roof structures
•  Second rows of solar panels.

Therefore, the calculator’s production estimate must be considered alongside the actual conditions at the installation site.

Testing solar shading for roofs in Pakistan

Before installing solar panels, inspect the proposed installation area at different times of the day.

Check the morning, afternoon, and afternoon shade.

Look at the roof in the morning, near noon, and later in the afternoon. This can reveal shadows that may not be visible during a single inspection.

Identify permanent ceiling obstructions.

Check water tanks, parapet walls, stairwells, antennas, satellite dishes, and other objects that may block sunlight.

Consider nearby buildings and trees.

Shadows can form across all parts of the roof from neighboring properties and vegetation, especially when the sun is low in the sky.

Check the spacing in the solar panel row.

Where several inclined rows are installed, the arrangement should minimize unnecessary shading from one row to the next.

Discuss shading with your installer.

Ask how existing and potential shading has been considered when deciding on the final panel position and layout.

Example: Estimated solar energy production in Lahore

Imagine you are considering a 10-panel solar system in Lahore.

Example input

Location: Lahore, Pakistan
Number of Panels: 10
Panel Wattage: Enter your actual module rating System Efficiency:
Enter your preferred planning estimate.

After running the calculator, compare:

•  Annual solar generation
•  Average daily generation
•  The most productive month
•  Monthly generation
•  Recommended panel tilt

This gives you a useful starting point for understanding seasonal production before you evaluate roof suitability and final system sizing.

Use live calculator results for real data.

Example: Comparing 8 and 12 solar panels

Suppose you want to compare an 8-panel system to a 12-panel system in the same property in Karachi. Leave the location, panel wattage, and system efficiency values unchanged. Calculate the result with 8 panels, then repeat with 12 panels. Compare annual and monthly generation figures to see how the estimated output changes as the number of panels increases.

This type of comparison can help when considering different system sizes, although the final number of panels should also reflect power consumption, roof space, and system design.

Example: Understanding seasonal solar production

For systems in Islamabad, enter your location and planned solar system details. Compare monthly generation data instead of focusing only on annual generation. This makes it easy to see how much solar energy production is expected to change throughout the year and why the annual total alone does not show the full seasonal picture.

Tips for getting a more useful estimate

For better comparison:

•  Enter the most accurate location available.
•  Use the actual number of panels you want to install.
•  Enter the wattage shown on your panel’s specification sheet.
•  Keep the same performance value when comparing different setups.
•  Review monthly as well as annual generation.
•  Consider physical roof shading separately.

The calculator is most useful as an initial comparison and planning tool.

Factors that can affect actual solar yield.

Your real-world solar generation may differ from the calculated estimate because:

•  Trees, buildings, and other sources of shade
•  Panel direction and orientation
•  Roof angle
•  Dust and dirt on the panels
•  Local weather conditions
•  High temperature
•  Inverter and wiring disadvantages
•  Equipment performance
•  Installation quality
•  Changes around the property over time

The current calculator does not publish its full irradiance dataset, calculation formula, or CO₂ conversion methodology. Therefore, its results should be considered as estimates rather than guaranteed engineering data.

For final system design and installation decisions, have a qualified solar professional inspect the property.

Who can use this solar calculator?

The calculator may be useful for:

•  Homeowners are considering rooftop solar power.
•  Businesses comparing solar system configurations
•  Buyers are estimating potential solar production.
•  Students are learning about seasonal solar generation.
•  Solar installers are conducting initial testing of the system.

It is designed for initial estimates and does not replace structural, electrical or detailed shading reviews.