Operation and optimal sizing of combined P2G-GfG unit with gas storage for frequency regulation considering curtailed wind power

Abstract

The increase in penetration of wind turbines in the power system has caused curtailment of wind power due to the stochastic nature of wind, which results in loss of revenue. Consequently, power to gas (P2G) has emerged as a device which can utilize curtailed wind power through the electrolysis of water to hydrogen or further processing to obtain methane. In addition, due to technical, economic and environmental benefits, the share of gas fired generating (GfG) units in power systems has been rising by replacing fossil fuel fired generating units. This paper proposes a coordinated operation and novel optimal sizing of a combined P2G-GfG system (CPGS) with gas storage tank (GST) for participating in frequency regulation. Firstly, the coordination operation of CPGS is presented in which P2G utilizes the curtailed wind power to facilitate the methanation process to produce methane. The methane is stored in a gas storage tank, then a GfG unit is supplied with the gas to participate in frequency regulation. Secondly, a novel optimization model using particle swarm optimization is presented considering the operating strategy and operation constraints to maximize net benefit when CPGS participates in frequency regulation market. Finally, case studies were conducted to verify the proposed coordinated operation and optimal sizing strategy considering actual AGC commands and curtailed wind power data.