**Describe the bug** As reported by @kdebrab in this https://github.com/pvlib/pvlib-python/pull/717#pullrequestreview-2274231371 comment **Expected behavior** the line is meant to start with `f_gnd_beam =` and clip it at max zenith so values don’t blow up. **Versions:** - ``pvlib.__version__``: <=0.11.1