I have a detached garage which is about 12 ft from the house and which has a separate workshop area. Expected load is portable tools and supply to recharge the plugin hybrid. I will also be supplying the main house when power goes out (from car), when there is excess photovoltaic power (to be installed) and/or when a separate static battery bank is installed and were off grid.
I was thinking of burying 3" PVC to house electrical and future water lines for carrying heated water (solar thermal). Should these conduits be separate or can I nest one inside the other? Should I use 12-2 wire or THHN/ THWN and with what housing? Also, I cannot dig to 12" unless I go below the footer (see pic).