ESS (energy saving system) is an intelligent control system to optimize the ship’s central seawater cooling system (CSCS). The ESS is a system efficiently managing the pump operation of the CSCS system by monitoring the marine environment conditions during the ship's navigation. If ESS is used in linkage with Donghwa Entec’s plate cooler, the innovative energy saving of the CSCS is possible. ESS can be applied to various motors and pumps used on a ship, and energy efficiency improvement can be expected according to the environmental conditions through professional technical support.