Superconductive energy storage for large systems

A summary report of a three-year study of superconductive energy storage for large utility systems is presented. The preferred conceptual design choices include: large, thin-walled solenoids, 1. 8 K cooling, TiNb in aluminum composite conductors at 5 tesla, bedrock structural support for both axial and radial forces, and a three-phase Graetz (ac/dc) bridge converter interface to the power grid. Preliminary estimates show that capital costs are given by $/kW = 40 + 125 (P/1000)^-1/3(t/2)^2/3Where P is the average power in MW and t is the discharge (peaking) time in hours. A typical operating loss is 10 ∼ 15% of the stored energy. The concept is technically feasible requiring only present day technology.