I'm afraid the flywheel won't spin for even close to an hour once the pedaler stops pedaling.  150 watts is possible for a person to produce for an hour or more if you're in very good shape.

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..

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nothing to lose

You want to inject 150 watts for 1 hour and recuperate 150 watts for 6 hours !!

This is not free energy --THIS IS ETERNAL ENERGY ---

The DREAM of humanity

Clear indication that you do not know any principles of energy, energy producing, energy harvesting, efficiencies and etc. and etc, Human power capabilities, and etc in physics and other sciences.

YOU HAVE SAID:
>>>>I'm just a suburban husband whose wife thinks he is crazy already

Tell your wife: Yes I am crazy !! And give her this message

I presume you meant 800KWH.

Your real problem is the size of your utility bill. Your problem can be solved with one word; CONSERVE.

Replace most of your lamps with compact fluoros. Turn them off when not in use. Turn off the heater & put on a jumper. Turn off the air-con & open the windows instead. There's lots of others. The first few simple ones won't cost much, and will save heaps.

Seriously, having built a pedal driven custom made hand wound permanent magnet alternator myself, I can state with pretty good certainty that you'd do extremely well to put 100 watts into the utility system after you acount for losses.  50 watts or less would be more realistic.  A flywheel of any kind will not change that number appreciably.

By the way, the economics of your scheme don't work any better than the physics.  A typical grid tie inverter, by itself without the installation or the permits or the other bits and baubles will generally cost a couple grand at least.  Cheapie MSW inverters CANNOT hook up to the grid without very bad things happening.

Good luck and have fun!

I'm afraid your expectations are in for some serious adjustments, but I encourage you not to give up hope that you can make a dent in your electric bill.

I have built a few spring motor powered prototypes with very heavy flywheels and found that anything over a five minute spin down to zeroe requires a huge imput and minimul generation drag to achieve. That said, your idea of utilizing a multi geared bike to spin up a ( balanced ) 200 lb flywheel to generate electicity has merit as long as you modify your power output expectations accordingly, and are willing to do a little research as well.

Again I encourage you to keep trying, there's a law of physics that states you get out of a project what you put into a project, the more you put in the more you get out.

Best of luck.

The flywheel will be good for decogging the generator, and to maintain the torque on the generator in those (very short) moments where you are not pedaling at full power (the pedals in the vertical position)

If you want to "work like hell" for a few minutes, and in this time produce a large amount of electricity, then you can use a bicycle with some heavy gears as the basis for the generator - you will not get more energy than you put into it, but you will save some time, which i guess is what you want.

With a budget like yours: What is your reason for not buying a soladin grid tied inverters and 145 watt of solar? - this will do the trick for you....?

Consider a 200 pound flywheel rotating at 5000 RPM with a center of mass 2 feet from the hub. The diameter is 4 .. so every revolution is 12.57 feet, 62,831 feet per minute or 1047.2 feet per second. Square that and you get 1,096,628 multiply by 200 ... 219325568 ... divide by 2 ... 109,662,784.

The stored energy is 109,662,784 foot pounds and since 550 foot pounds per second is one HP you can get 199,387 horsepower for one second or 55.38 horsepower for one hour.. and for home generation 5.538 horsepower for 10 hours. I would cut that in half because you will have aero and friction loss.

The problem is the army of men necessary to pedal it up to speed in a time similar to its output time. I would start an excercise studio, charge memebership, gang the excercycle pedals to a shaft that is clutched and geared (50 to 1) to a 200 pound flywheel at each end. When one flywheel is up to speed it is connected to the generator and the other, depleted unit is spun up by the cyclists.

If you want to get greedy you can locate your human generating plant in San Francisco, contract for a dominatrix to beat those cyclists who will pay large sums for this treatment and really cash in both from the power generated and the clients. I don't know what this really accomplishes however because I don't think that a human is a very efficient converter of energy. The postulated pedaling submissive probably eats beef and that requires all that tractor and transportation diesel needed for the associated agriculture.