Free electricity

Since a few days I have installed solar panels at home, which would normally create just a little bit more energy than we normally use in an entire year. So there is room for some extra electric usage in the form of a mini Bitcoin or multi mining farm...

I have already done some diggin in the net and most forums don’t really agree on the profitability... So I am putting the question in the open here on Hive... Can it be profitable if electricity is free and what hardware do I buy?