Cost Analysis of a Conceptual Long Duration Pumped Storage Hydropower System in an Underground Mine

This paper presents the cost analysis of a conceptual pumped storage hydropower system that would use an abandoned underground mine in Indiana as the lower reservoir of a closed-loop system to achieve long duration energy storage. A MATLAB based tool is developed for the technical design and cost analysis of the system. A sensitivity analysis is performed by varying the key input variables by −10% and +10% from the nominal case to identify the impact of each variable on the cost estimates. Based on the sensitivity analysis, 10 different design configurations are simulated to calculate the specific power cost, specific energy cost, and levelized cost of storage. These cost parameters are compared to the Department of Energy's cost targets for pumped storage hydropower systems. It is found that daily generation hours and cost associated with erosion prevention of the surface inside the mine are the two most critical variables. It is also estimated that by choosing the appropriate design configuration it is possible to achieve up to 13% cost reductions compared to the target.