I am afraid the style API for the axis label currently does not support an easy way to do that.
I am afraid the only thing I can suggest is a kind of a hack e.g. add some text white space to achieve the effect such as :
yLeftAxis.title = @"Straty (MWh)\n";
This should insert a blank text line between the labels and the title.
Hope that helps.
Check out the Telerik Platform - the only platform that combines a rich set of UI tools with powerful cloud services to develop web, hybrid and native mobile apps.