Earthly Solutions: Optimizing CAPEX with Compressed Earth Blocks in Gravity Energy Storage Systems
P. Kropotin, R. Sokolov, J. Toth · 2025
The capital-to-capacity expenditure ratio (CAPEX) stands as a key competitive metric for energy storage systems. One of the major cost items in gravity energy storage systems is weights. In order to reduce costs for weights, it is proposed to use unstabilized compressed earth blocks (uCEB) instead of traditional construction materials. This material has a density similar to reinforced concrete but can be made from earth extracted from the site during the construction of the foundation. Instead of transporting this earth away, it can be utilized for weights. Along with earth, fly ash from thermal power plants, recycled wind turbine blades, and other industrial waste can also be used. This technology not only brings capital cost savings but also reduces carbon emissions and introduces elements of a circular economy into the project. The paper presents the cost of uCEB and the impact of reducing carbon emissions. A comparative analysis of the cost of using other materials for weights is conducted, as well as an aggregate assessment of capital expenditures for the construction of gravity energy storage systems.