Linear Electric Machine-Based Gravity Energy Storage for Wind Farm Integration

In this paper an above-ground, dry gravity energy storage system to help integrate wind energy sources into the energy mix, is described and developed. Using the principle of gravitational potential energy and a single piston example, multi-piston shafts and multi-shaft systems are proposed. From this analysis, some of the basic characteristics of the system, such as round trip efficiency and energy density, is derived. Using a generic wind farm and available literature, the paper discusses how the system can be constructed and used to help integrate wind farms with an electrical grid, while also demonstrating the comparatively small surface area that the storage system requires.