Analysis of a hybrid energy storage system in a grid-tied wave energy converter for varying power demand

Wave energy is one of the emerging sustainable energy resources due to its high energy density and vast untapped areas. Nevertheless, the intermittency of wave resource is a significant challenge for the grid operator. Additionally, a varying grid demand is an added complexity to wave resource. Energy storage systems such as batteries and supercapacitors can be used to smoothen the power injection into the grid and match the available energy with the grid demand. Thus, this study compares battery energy storage with the hybrid energy storage system and proposes a control strategy to reduce the power fluctuations on the battery, allowing power delivery for varying grid demands. The study found that the hybrid system increases the system efficiency, in addition to the reduction in power fluctuations and enhancement of battery's performance, among other gains when the proposed control is implemented.