Optimal Renewable Energy Integration Considering Minimum Dispatchable Generation Operating Costs

This paper proposes a method to determine the optimal renewable energy (RE) integration in the electrical system considering the minimization of dispatchable generation operating costs. The RE generation consists of solar and wind generation while the conventional generation, which is considered as the dispatchable generation, consists of natural gas combined-cycle and coal thermal generation. In the analysis, a unit commitment is executed based on the operating costs, i.e. variable costs and load following costs of the dispatchable generation. Moreover, the proposed method is aimed to accommodate the electricity demand with the consideration of generation characteristics such as minimum generation, ramp rate, minimum uptime and minimum downtime. The result shows that the optimal renewable energy integration is at 40% of the total electricity demand. Beyond the optimal level, the dispatchable generation operating costs tend to be higher because of the RE compensation operation.