Gravitational energy storage by using concrete stacks

Abstract

This article purposes to study theories of gravitational potential energy as an energy storage system by lifting the weight of concrete stacks up to the top as stored energy and dropping the concrete stacks down to the ground to discharge energy back to the electrical power system. This article is the analysis and trial plan to create an energy storage systems model with the vertical concrete stacks to form a suitable configuration. The gravitational energy storage system is an energy transformation between the gravitational potential energy and the kinetic energy of the concrete stacks moving down to the electrical energy via a generator. A comparative efficiency study of the charging and discharging energy system during lifting and dropping concrete stacks are also presented. The case study is based on the feasible square prism concrete stacks in vertical shape with a weight of 100 tonnes per stack. The height of the system is about 50 m. As the result, the power system obtains the energy from the gravitational energy storage as a discharging mode by 9.68 kWh, however, supplies the energy to the gravitational energy storage as a charging mode about 12.10 kWh with the overall efficiency of 80%. The finding in this study, the discharging mode of the gravitational energy storage is suitable to use in the power system to support the high demand during the on-peak time or the duration of the high cost of electricity whereas the charging mode is possibly used in the duration of off-peak time with low cost of electricity or supported by the renewable energy sources around.