The purpose of this paper is to review the work that has been done on how humidity, salinity and water droplets affect the offshore wind turbines electrical stator winding insulation. Partial discharges (PDs) could be both the reason of the insulation's deterioration as well as the result of this deterioration and they are linked with the aging of the insulation system. The presence of humidity, salt and water environment offshore can exasperate the occurance of PD. Wind turbines, onshore and offshore are one of the most promising areas of research. Offshore wind turbines have to operate in harsh environmets such as marine environment that could affect even more their lifetime.