California Civil Code Section 714(a) provides that “Any covenant, restriction, or condition in any deed contract, security instrument, or other instrument affecting the transfer or sale of, or any general interest in, real property, and any provision of a governing document … that effectively prohibits or restricts the installation of use of a solar energy system is void and unenforceable.” California subsequently clarified that restrictions that do not affect price or system efficiency by more than 10% or $1,000 are permissible.