John Carmack (@ID_AA_Carmack) “I DIY’d my first off grid solar power system to get experience with all the piec” — TopicDigg

I DIY’d my first off grid solar power system to get experience with all the pieces, but I had @QualitySolarTX build a bigger one for me recently. 24 kW of panels, 30 kW of inverter, and 75 kWh of battery. I initially planned on using 15x @bigbatteryinc Ethos batteries with a single battery controller and a single Sol-Ark 15k inverter, but I realized that 15kW of power wasn’t enough – if I was charging a Tesla at max rate, a tankless electric water heater couldn’t run at the same time. Going to a dual 15k system gives plenty of margin, but it then made the single battery controller the limiting factor. I could have just added a second one, but the asymmetry would have nagged at me, so I wound up with three battery controllers. I might wind up stacking three more Ethos modules into the system. Unfortunately, a dual SolArk and multiple BigBattery BMC system won’t all talk together properly on CAN bus, so the battery charging is open loop for now. I think about the off grid property as LARPing a Mars base.  😀