Investigating the Flexibility of Power-to-Gas in Ramping-Constrained Unit Commitment

A high share of renewable energy generation penetrated to power systems leads to dramatic volatility and uncertainty of net load, thus increasing the demand for flexible regulation resources. Power-to-gas(P2G) technologies have gained substantial popularity in the role of virtual storage to transform surplus renewable energy to hydrogen that is then utilized by gas turbine for power generation. In this paper, we investigate the contribution of P2G in ramping-constrained unit commitment (UC). According to the characteristics of proton exchange membranes, we model the nonlinear relationship between hydrogen production and electricity consumption. A UC model is formulated considering a piecewise linear model of P2G, which is aimed to minimize the total operation costs with flexible ramping requirements embedded. Illustrative cases demonstrate that P2G can significantly enhance the ramping flexibility of power grids, while improving both system-wide economy and reliability.