The amount of solar energy captured by a photovoltaic panel depends heavily on the angle at which sunlight strikes its surface. Aligning the panel perpendicular to the sun’s rays maximizes incident irradiance, which directly boosts power output.
Two geographic factors dominate the optimal tilt: the site’s latitude (phi) and the solar declination (delta), which varies throughout the year as the Earth orbits the Sun. The declination can be approximated from the day‑of‑year (n) using a sinusoidal relationship.
By adding the declination to the latitude, we obtain a tilt angle (beta) that points the panel toward the sun’s average position for a given day, providing near‑optimal yearly performance.
\phi = latitude (°)
\delta = solar declination (°)
How does latitude affect the sun angle?
What is solar declination and how does it vary?
How can I calculate the optimal tilt for my solar panels?
Why is it important to align solar panels with the sun’s rays?
How does the day of year affect solar panel positioning?
Results are for informational purposes only and do not constitute professional advice.