According to the California’s Solar Rights Act which is a “legal framework for solar access,” CC&Rs (the rules governed by Homeowners Associations) can not prohibit solar energy system installations.
California Civil Code Section 714(a), in pertinent part, provides that “[a]ny covenant, restriction, or condition contained in any deed, contract, security instrument, or other instrument affecting the transfer or sale of, or any interest in, real property . . . that effectively prohibits or restricts the installation or use of a solar energy system is void and unenforceable.” This applies to residential, commercial and industrial leases.
California has a strong commitment to solar energy. The California Public Utilities Commission found that California needs to triple rooftop solar to meet its clean energy targets. Some research states that at least 80% of our homes need to be powered by solar in order for us to make a difference in the environment. So don't let an HOA stop you!