A hydrogen generator and method for generating hydrogen gas for a fuel cell stack. The hydrogen generator includes container, and a first reactant storage area configured to contain a liquid first reactant. The hydrogen generator also includes a reaction area and a solid second reactant within the reaction area, and a hydrogen outlet. The hydrogen generator further includes a flexible liquid delivery member extending into the reaction area and configured to deliver liquid reactant from the first reactant storage area to the reaction area. The flexible liquid delivery member includes a flexible portion that flexes to allow the delivery member to move with the solid second reactant as the second reactant is consumed.