I am in the design phase of my 1st rig to mine ethereum, I am going to try and use only engergy produce from our sun....it's going to be tricky though because I will need to write a program and design the hardware that will allow the system to convert to ac when the power that I collect from the sun is not enough. My design will allow for the system to run non-stop while hopefully only running on AC power for 5-10 percent of a 24 hr period. Thanks for the post...very informative!!