ULV bat box or transformer for use with tin wire

You don't have to build a lossless cable.
If your windmills are 256 blocks above your base (longer than the maximum possible distance, if it's straight up) then you can transform the power to EV and then use 3xins. HV cables for a 10% loss.
If you don't have that much rubber, use uninsulated HV cable instead for 12.5% loss, and don't get zapped.

(is this a necro? the thread was only on the second page)

He said glass fibre was too expensive.