Impact of short term electricity procurement of an open access consumer on Indian grid

Unscheduled Interchange (UI) mechanism has emerged as a powerful tool for maintaining grid discipline, penalizing the market players, causing deviations in the system. A buyer pays UI penalty for over-withdrawal of power more than the scheduled one based on the grid condition. Such buyers having demand fluctuations may end up paying UI penalty at the real time. This paper proposes a planning model for a large open access consumer in India, purchasing from bilateral contracts and multiple Day Ahead Markets (DAMs). The proposed model can shift consumer's expected demand by accounting the UI deviations to minimize procurement cost. A small self generation unit and renewable purchase obligations are also considered. This work considers price uncertainty of both markets. The overall problem of cost and risk minimization is handled by mean variance approach. Results indicate that the consumer can plan demand scheduling for the planning period as well as can help in improving grid frequency at the real time.