I live on a 2.5 acre lot. I installed a ground mount solar array 6 years ago. Then 4 years later my neighbor planted over 39 tall cypress trees which are blocking the sunlight. Is there any law in Maryland that protects the solar owner?
Maryland has no law requiring a neighbor to not plant / trim trees that might shade a solar panel (on the ground or on the roof). There are laws against deeds, declarations, covenants, contracts etc. (excepting registered historic properties) which prohibit of roof panels (e.g. as part of a HOA's rules). The law also recognizes the right to enter into an easement agreement, but that requires agreement by the neighbor. California has a law requiring tree trimming that would cover this case.
I am not a lawyer. I do not fully know of the current case law or climate of this type of law in Maryland. The cause of action you are looking for is private nuisance.
“Section 821D of the Restatement (Second) of Torts (1979) defines a private nuisance as a nontrespassory invasion of another’s interest in the private use and enjoyment of land.” See Echard v. Kraft, part III (internal citations omitted).
“Nevertheless, not every interference with the use and enjoyment of land constitutes an actionable nuisance, inasmuch as the interference must be both substantial and unreasonable.” (Ibid)
The facts you have stated may be considered private nuisance, but generally I would think your case is on shaky grounds. To be successful this is not something you should delay in resolving in any way and you will definitely need to hire an attorney. The statue of limitations is generally 3 years so do not delay if you wish to bring a cause of action. After 3 years, you cannot do anything. You may still be able to bring a cause of action because you only realized the trees were a permanent condition two years ago. There are other reasons the statue of limitations may be overcome in this case, ie if temporary nuisance instead of permanent nuisance is established.
An attorney who has experience with this statue should assist you because there is a considerable amount of case law that needs to be evaluated to resolve the question of whether or not a suit should be brought. Additionally, an attorney may be helpful in evaluating if there are any other claims you could be successful in bringing.
I would definitely recommend against going to your neighbor and telling the neighbor you plan to sue him/her for nuisance and to fix the trees right now. Definitely do not file an action yourself as private nuisance seems to be very deferential to the defendant in Maryland and by hiring an attorney, the attorney representing you will be able to craft the best argument in favor of your claim.