Bid Determination Method for an Electricity Market with State-of-Charge Maintenance of a Compressed Air Energy Storage System Using the Prediction Interval of Wind Power Output

The use of power from wind power plants (WPPs) has increased in recent years, and the power from WPPs can be traded in electricity markets. Operators of WPPs need to determine bid volume before the power is supplied to the electricity market. The bid volume can be determined based on the power forecast data; however, uncertainty in the power can lead to imbalance between the bid volume and the actual output from WPPs. Using an energy storage system (ESS) is an effective solution, but the state-of-charge (SOC) should be maintained at an appropriate value to effectively use the ESS. Bids often include the energy required for SOC maintenance. However, imbalance can occur if the energy equals the ESS rated power under uncertainty because the ESS cannot use more power than the rated power. Therefore, the control of the energy required for SOC maintenance should be discussed. In this paper, we propose a bid determination method using a prediction interval to reduce imbalance by controlling the energy required for SOC maintenance. Wind farms with a compressed air energy storage system are considered, and numerical simulations are performed. As a result, our proposed method with the prediction interval can reduce the degree of imbalance in comparison with methods without the prediction interval. Keywords—bid determination, electricity market, energy storage system, prediction interval, wind power