Control and Power Balancing of an Off-Grid Wind Turbine With Co-Located Electrolyzer

Abstract

Co-locating electrolyzers and offshore wind can significantly reduce the cost of green hydrogen. However, without a grid connection, a new control paradigm is required for the electrolyzer to follow the variable power supplied by the wind turbine. Commercial electrolyzers have power ramp rate limitations, which can result in a mismatch between the wind turbine and electrolyzer power, leading to frequent shutdown and potentially unstable operation. This paper is the first to develop a control system for this off-grid operation with three mechanisms to dynamically balance the power, including energy storage, rotor inertia, and enhanced pitch control. The results show that a $6.8 million supercapacitor is required with a power rating and capacity of approximately 6.7 MW and 8.5 kWh to enable the system to operate through 99% of the annual wind variation. If the electrolyzer ramp rates can be doubled, the same operating hours can be achieved using only control-based power balancing methods at the cost of a marginal reduction in energy production. If commercial electrolyzer ramp rates can be tripled, the system is able to operate without the need for any power balancing.