On highly hydrophobic surfaces, water droplets tends to remain as droplets due to the strong hydrophobic properties of the surface. Many authors [6.5, 6.6, 6.7], have used hemispherical shapes to model water droplets, These droplets were modelled with diameter ranging between 1 and 3 mm and 90˚ contact angle. Field enhancement on the insulator surface due to water droplets may reach 50%, as reported in [6.5]. Other authors [6.7] have used water droplets for modelling insulator under rain and fog conditions. For the rain model, the droplets were created only on the upper surface while the underside was kept dry. The same model was adopted for the fog condition with the bottom shed surface being covered by a thin continuous water film. Therefore, Weigue et al. [6.8] have introduced a more practical droplet model,