I'm paying £0.06 at the moment and I got paid to use electricity on the weekend thanks to the sun shining and wind blowing.
I call bullshit on this claim. Sure, you might be paying pennies a kWh, but likely only for a few hours at midnight, then it spikes to £0.50 during peak times.
I don't know how you're accomplishing that.
The lowest mine goes is $0.3 1am-4am.