Montelibero free city,. they mine ,. not for the coins but for the heat to warm the water for building heating and a hot shower . The power comes from solar panels and so has no mention in the way of cost's . The choice made to use older crypto mining rigs instead of a solar water heating system was done after comparing it's functions ,. they where quiet the same . With as plus for mining ,. it might hit the right block one day and produce some coin . But main function is a water heating system with zero electricity cost's .
;-)