Optimal sizing of battery energy storage for grid-connected and isolated wind-penetrated microgrid

Renewable energy (RE) sources, particularly wind and solar are gaining more popularity due to their inherent benefits, consequently, nations have set ambitious goals to enhance the penetration of RE into their energy-mix. However, the RE sources especially wind and photovoltaic sources are intermittent, uncertain, and unpredictable. Therefore, there is a need to optimize their usage when they are available. Moreover, energy storage system like battery energy storage has much potential to support the RE integration with the power grid. This study, therefore, investigates the sizes of battery energy storage required to support a grid-connected microgrid and a stand-alone microgrid for 12 months considering hourly wind power potential. In this study, we have considered three Scenarios of operations and have determined the BESS sizes and recommend the best based on the cost of operation. Scenarios 1 and 2 are grid-connected configuration while Scenario 3 is a standalone microgrid supported with diesel generators. In each Scenario, the optimization problem is formulated based on the optimal operation cost of the microgrids. The powers consumed from the main grid are reported in Scenarios 1 2 and the extra cost spent on the maintenance of diesel generators is reported in Scenario 3. The study evaluates and analyzes the operational environmental effects and costs between the three Scenarios. The formulated problems are solved using the nonlinear optimization method. Simulations results proved the effectiveness of the study.