[phkahler]

>> in the order of 80-90%

I've been in the EV world for a while now. We used to do 100-200kW drive systems where motor+inverter would be 90-94 percent efficient. Adding a single stage gear to that would cost another 1-2 percent efficiency loss.

The whole time I was reading this I kept thinking we could throw 100 electric vehicle drives on a giant ring gear for a total mass under 10k-tons with no super conductors or anything too fancy. The problem is that the EV systems are not rated for continuous operation at higher power levels. You only use full power for acceleration - driving even at highway speeds doesn't take that much. OTOH one would expect good airflow in a wind application.

I think there might be room for a change of approach in the wind turbine area.