Yellow is NASA's data for a flat, horizontal surface. Blue and green are our estimates for a tilted panel at the angles shown, facing the direction set in Step 3, with no snow cover assumed.
Choosing the right solar panel tilt angle is crucial for maximizing your system's energy production. This calculator uses NASA satellite data (2002-2022) for sunlight on a flat surface, then estimates what a tilted panel receives, to give location-specific guidance for Canadian solar installations.
The year-round angle is a compromise between seasons. If you can adjust seasonally, you can improve performance:
Fixed mounts are simpler and more affordable — ideal for most residential installations. Set them once and leave them.
Adjustable mounts allow seasonal tilt changes, which raises winter output and lets snow slide off more easily. The estimates above show the gain for your city. Worth considering for ground-mounted systems. A popular option is the adjustable ground mount bracket on Amazon.ca.
If installing on an existing roof, compare your roof pitch to the optimal tilt shown:
Related tools: After determining your optimal tilt, use our battery bank calculator to size your storage. Not sure which way true south is, or whether trees will shade your panels in winter? Try our sun path calculator.
Size MPPT or PWM charge controllers for your solar array
Calculate how many panels you need for your system
Size your battery storage for off-grid systems
Find the correct AWG for your solar cables
See sun direction by season and check winter shading
Month-by-month output by province, with snow loss
Use the year-round angle shown for your city if you want the most energy over the whole year. If your system has to get through winter on batteries, a steeper angle (about your latitude + 15°) gives more December to February sun, and many people with fixed mounts choose a compromise between the two. The Which angle should I choose? table shows the estimated trade-off for your city.
If it is practical, yes. Tilt steeper in winter (about latitude + 15°) and shallower in summer (about latitude − 15°). That raises winter output, helps snow slide off, and can reduce the battery capacity you need. Fixed installations still work well if you pick the angle that suits your priorities.
GHI (Global Horizontal Irradiance) is the solar energy landing on a flat, horizontal surface, in kWh/m². PSH (Peak Sun Hours) expresses that energy as equivalent full-sun hours per day, which makes panel output easy to calculate. A tilted panel receives more than a flat surface in winter, so this page also shows estimated sun hours on the panel.
Small deviations cost little, and the loss grows as you turn further toward east or west. Use the orientation slider in Step 3 to see the estimated loss for your city and tilt. A compass points to magnetic north, not true north, so measure true south carefully.
Once you find your city's PSH, use it to calculate your battery capacity, determine your solar panel wattage, and size your inverter. Start with our battery bank calculator and solar panel calculator.
Flat-surface sunlight values come from NASA POWER monthly averages for 2002 to 2022. Sun hours on a tilted panel are our estimates, calculated from those values with a standard sky model and 0.2 ground reflectance (no snow), so real winter output can differ with weather, shading and snow. Treat all figures as planning estimates.
Steeper panels shed snow more easily, which is another reason to favour the winter angle in snowy regions. Keep the lowest edge of the array clear of the ground and of drifts so snow can slide off.
Yes. The sun hour estimates apply to grid-tie and hybrid systems too, although for grid-tied systems the year-round angle usually makes the most sense because total annual energy matters most.