"I'm just a suburban husband whose wife thinks he is crazy already"
I agree with her
Just joking of course, but I think there is many problems with this idea.
" My only concern is I could be wrong about how long the flywheel could spin, if it is only about an hour this won't work."
I may spin not quite as long as needed to almost produce the power you put into it as electric back out of the genny, there will be some losses so it's not equal in/out.
First the way I see it (but could be wrong) is that 150watts is 150watts no matter how or when you make it, right. SO, if you rode the bike all day constant making 150watts direct to the gennie you have no bearing losses extra gearing losses and all the other things that may cause extra losses when using the flywheel. You have to produce that much power then to drive the flywheel and cover any extra losses I mentioned like bearing frictions so you have to provide a little more power even.
So 150watts x 24 hours = 3600watts per day. I order to power the flywheel 2x's a day and produce that in electric you have to put in over 1800watts each time. 4x's a day is still over 900watts each time. Take in for losses and you jump to 2000 and 1000 or more input each time. Don't know if that would even work really myself. But still if you could do that, might as well just go direct and forget the flywheel, power is power and if your feeding the grid who cares if it's all at once or spread out durring the day? Now if you were trying to power your own needs then spreading it out might be worthwhile.
Now it is said a person in decent shape can produce about 100watts continous for a while or a little more maybe, about 150-200watts for a short burst, if I remember the figures correct.
No matter how you gear the flywheel you still have to provide that power. Either peddal HARD and slow, or peddal really fast but easier, depending how your gears are setup or changed. BUT, either way it is still the same basic effort and result. You put out 100watts of your engergy to make the genny provide 100watts of electric.
Now by using a flywheel it might help make constant running a bit easier, eliminate the lummpy spots, provide for a brief break to relax, keep the genny spinning while changing riders etc.. but the gennie has a load on the flywheel equal to the power it puts out plus a little. So if you have 150watts electric being made you need to power up the flywheel to about 300watts if you want to take a short break. Now this would be good for changing riders, the first gets it going which takes alot of work, the next just keeps it going at a constant rate and so forth.
I try to keep the pedal power a person can produce in mind, though my mind is full of many other things so I get a bit slow at times with numbers. Since I am thinking of electric vehicles like bikes and 3 wheelers this info is useful to eliminate false statments by others supposedly knowing more than me (mostly local). In other words when someone tells me it takes 2HP and 10amps 120Vac to move a 3 wheeled bike down the road, I KNOW they are wrong! If a person peddals a bike at 100watts per hour and can move the same bike down the road then it takes .83333amps at 120Vac or 8.3333 amps at 12VDC. FAR less than any 2HP motor I ever saw
So at 115 amphrs per deepcycle battery at 50% discharge I get 57 amps/9= 6.3333 hours at normal peddaling speeds (aproxamate).
Now add in wieght of batteries and motor etc.. I might get into the 10-15amp 12Vdc range or 1-1.5amp 120Vac. Even 15amps is close to 4 hours at half cycle on 1 battery, plus your not always using power, sometimes you can freewheel or downhill brake.
If you have many short hop type trips you make alot, might be a bike idea for you better than the flywheel genny. Still have to pay for electric and maybe more to charge the bike, but look what you could save on gasolene! Could build a small wind genny to charge the bike. OR a peddal powered genny from the exercise bike as direct drive. Just sit there and casually pedal at night in the comfort of your home while reading a book or watching TV over a long period of time taking breaks whenever. THEN when you got the long hard ride in the hot sun you ride free and comfy letting the batteries do the work
My plan I am gathering parts for is a powered bike trailer. Some places have lots of laws and restrictions on motorized bikes, I no of nothing about motorized trailers
The bike is still pedal power only
Also as a trailer unit you could use one for several bikes, just have to mount the controls when you change bikes and connect the hitch. So a 3 wheeler, 2 wheeler, etc.. could use the same trailer at different times and you always have peddal power as a backup. If you wanted to make long trips to the same place often like I might, you build 2 trailers, one for each end of the trip. Charge one at home and one there, ride one way swap trailer and ride back
I do have a place to store and charge the second trailer at the other end and that of course is very important. No advantange of leaving a dead trailer to stay dead.
I will also be able to haul things on the trailer as a trailer. Car parts, groceries etc..