All in with controller, batteries and PV panels I paid around €4000. Should get 5 -7 years from the battery bank this system knocks off approx €100 a month from electric bill so payback is around 40 months... the space heater S3 and Bitcoin is just a bonus.

Also, I wanted to add for anyone else reading that the new controller board I fitted does not allow the cover to be put back on the S3 and this has been a blessing in disguise. OC the unit to 250 Frequency now runs at just over 500 GH/s but temperatures are much lower remaining stable at 41 C. Temp's used to creep up around 45 - 47 with the cover on. Fans run always at 1,920 rpm which is not too noisy for me.