Sizing Energy Storage to Aid Wind Power Generation: Inertial Support and Variability Mitigation

Variable energy resources (VERs) like wind and solar are the future of electricity generation as we gradually phase out fossil fuel due to environmental concerns. Nations across the globe are also making significant strides in integrating VERs into their power grids as we strive toward a greener future. However, integration of VERs leads to several challenges due to their variable nature and low inertia characteristics. In this paper, we discuss the hurdles faced by the power grid due to high penetration of wind power generation and how energy storage system (ESSs) can be used at the grid-level to overcome these hurdles. We propose a new planning strategy using which ESSs can be sized appropriately to provide inertial support as well as aid in variability mitigation, thus minimizing load curtailment. A probabilistic framework is developed for this purpose, which takes into consideration the outage of generators and the replacement of conventional units with wind farms. Wind speed is modeled using an autoregressive moving average technique. The efficacy of the proposed methodology is demonstrated on the WSCC 9-bus test system.

I. Introduction

The penetration of wind energy into the power grid is ever-increasing, with the U.S. adding a record 14.2 GW of wind turbine capacity in 2020 [1] alone, despite the ongoing pandemic. Replacing fossil fuel powered electricity generation by wind energy is also crucial for achieving the goals set by the Paris Climate Accords, and this entails increasing the global cumulative installed capacity of onshore wind power to about 1800 GW by 2030 and 5000 GW by 2050 [2]. However, integrating this massive amount of wind energy into the power grid might lead to stability and reliability issues due to the low inertia and intermittent characteristics of wind.