I have a 20kW solar array that I installed myself.  Total cost was around $30k all inclusive.  The quotes I got were over twice that.

I have a net metering agreement with my POCO, so what I don't use goes back on the grid and the POCO credits me at the same rate I pay, so 1:1.  I'm in VA.

Before I started mining, I was actually building up a bank of kWh with the POCO since I didn't consume as much as I generated.

In June I generated 2,580 kWh and consumed 2,348,

In July I started mining and generated 2,846 kWh and consumed 3,974 kWh.

August was crazy hot.  I generated 2,474 kWh and consumed 5,245 kWh.

My kWh rate is fixed year around and is about $0.12 with everything included.  With the solar and assuming I consume twice as much as I generate, my effective rate is about $0.06 per kWh.  I plan to add another 6.5 kW array, which I can do for about $4,800 since I already have the inverters and just need to get the panels and some Ironridge rails and hardware.