In this day of lawsuits against everyone and enyone, general liability insurance with a high limit of liability is a must! That means $1,000,000 or more per occurance. Not only will the insurance company pay if you are found to be negligent, it will pay to defend you in the lawsuit, even if it is baseless and frivolous, filed merely to intimidate you.
Property coverage protects you against loss by fire, windstorm, explosion, vandalism, etc., but most importantly, LIGHTNING, which is a huge threat to any kind of power generating plant. a property policy should replace damaged property, but also replace lost revenues while you are out for repairs (business interruption coverage).