Since the emissions in the lifecycle of a wind turbine are from the energy used, the time period lasted would also be when it breaks even on CO2 emissions.
As for destroying energy, that's just the efficiency, the other 60% is wasted as heat.
The one in the post looks like it's polyester and foam. Why would plant based materials be better? I would think ideally you'd make the plastics out of ethanal and algie, but with how much processing goes into it, I'd hardly call that organic.
This was 19 September to 11 October 1957