This is interesting, I mean an exhaust fan 1750rpm 150 watts could in theory throw a huge mount of air around 6500 m³/h or 110 cfm and if there was a turbine motor, could it run it? I mean making electricity, from wasting electricity, the question is, will be worth it? I would say no cause there are no reports of people who successfully achieved or maybe they achieved and never came here to tell hehe, the only way to find out is try it and it will be a very expensive test.
Also about the topic in hand, the op said it worked, did it? If it worked for him, good, now I wonder what is he gaining to come here and tell his secret? If he wants to help great but make sure he will face a lot of angry miners who for many years spent thousands of dollars paying the electricity provider ehhe, so, op, make a video and upload to youtube and link here. I'm sure it will get a lot of views.
Yes your exhaust fan could run a turbine. Don't know how fast or how much it would produce but yes it can happen, one example of a newer technology is a turbine in the sewer system, everytime someone flushes their toilet or runs water it spins the turbine and produces power. A city in Arizona or California just installed these types of systems last year if I remember correct. So flushing your toilet produces electric.
I am not going to spend the time for a video when you have so many here who are jerks. There are thousands of videos online for these types of alternate power systems. We don't need another instead we need some to do more research on how a power inverter and a PMG generator works before flapping their gums. I don't have nothing to prove here I put the plan and parts list out for those who want to use. If you don't want to use it then just skip on by the thread.
You can also take an lg washing machine or dryer (newer ones) and spin the tub or rotate it back and forth and it will produce enough power to turn the units mainboard on. Found this by accident when servicing a washing machine one day. The type of permnant magnet motor drive allows this to happen.