Jean

Hello M. Mermoud, Thank you for this answer. I looked at the horizon shading loss in my PVsyst simulations and found strange results. I used the latest version, 6.8.6. I took a constant horizon height at 12° and I'm simulating a horizontal single axis tracker. For north-south rows (azimut = 0), everything looks fine, horizon shading loss on diffuse begins at around 4% (relative to diffuse incoming radiation) for horizontal panels and goes upwards with the tilt angle. When I take an azimut of -32° for the trackers though, horizon shading loss on diffuse begins at around 16%, goes down to 9% for tilts of around 30°, and then goes back up. For an azimut of +32°, shading loss on diffuse is 6% for horizontal panels instead of 4%. Do you also observe this strange behavior ? Thank you in advance, Jean

Hello, In the hourly output, we can see that when sun elevation lies between horizon elevation +-5°, beam horizon shade can be strictly smaller than beam incoming even when the sun is under the horizon, and also strictly positive even when the sun is over the horizon. Does anyone know the formula used for that, and why it is not as simple as "sun under horizon implies no beam light, sun over horizon implies no beam horizon shade" ? Is this formula used in the integral calculation for diffuse horizon shade ? Thank you, Jean