Estimating return on investment for grid scale storage within the economic dispatch framework

There is a global trend of deploying distributed grid scale storages in power systems for specific applications like, renewable integration, peak load management, congestion management, etc. Due to high capital investment, return on investment (ROI) for grid scale storage for any specific application is not lucrative enough for investors. However, if these storages are used across multiple applications, ROI could be more attractive than expected. In this paper, we focus on exploring the ROI when storage devices are used for applications such as transmission and distribution (T&D) system upgrade deferral and mitigation of renewable energy curtailment. We formulate an optimization problem to trade off the economic advantage of using storage devices versus its loss of life. While the formulation is generic and can handle any kind of storage, we focus on battery storage. We use detailed formulations to estimate loss of battery life to estimate capital expenditure (capex) on battery storage, on a per-day basis.