"25982. After the installation of a solar collector, a person owning or in control of another property shall not allow a tree or shrub to be placed or, if placed, to grow on that property so as to cast a shadow greater than 10 percent of the collector absorption area upon that solar collector surface at any one time between the hours of 10 a.m. and 2 p.m., local standard time."
There are a number of exceptions later in the act, including a notification requirement.
However, once a solar system is installed - a neighbor can't cause the system to be shaded with impunity.
http://www.leginfo.ca.gov/cgi-bin/displaycode?section=prc&gr...
"25982. After the installation of a solar collector, a person owning or in control of another property shall not allow a tree or shrub to be placed or, if placed, to grow on that property so as to cast a shadow greater than 10 percent of the collector absorption area upon that solar collector surface at any one time between the hours of 10 a.m. and 2 p.m., local standard time."
There are a number of exceptions later in the act, including a notification requirement.
However, once a solar system is installed - a neighbor can't cause the system to be shaded with impunity.