If you don't mind me asking how is your power free?
Even with free power I think you will be better off just buying and holding and you also won't have the hassle of dealing with mining hardware.
at the moment I don't think anyone will be free anymore, all of them need costs while doing mining will definitely still cost money whether it is engine maintenance or otherwise it will definitely need costs to be spent on mining.
Mining in fact can not be without costs. The equipment sometimes breaks electricity, too, almost never free. So there will definitely be spending even after purchase.
It's like a car you buy it and then spend money for insurance and gas. Plus the repair and replacement of filters.