A Dynamic and Productive Soccer Sideline?

Converting Potential Energy into Electrical Energy!

I have spent many hours driving to and watching our daughter's soccer games.  These are something I look forward to as it gets me out of the house even on cold and rainy days.

But these trips come with a bit of a guilt trip.  I fret about the many miles we drive and the gas we burn as hundreds of families descend on these soccer fields.  Also folks bring a folding chair and promptly plop it down on the sidelines, and then sit and shout for the whole game while encouraging kids to run faster and play harder.

Potential Energy ready for harvesting!

Would it not be great if there was a row of stationary bikes on the sidelines that were plugged into a device that could generate electricity and possibly even push it into the grid?  Yes, yes I know the amount of energy generated by a stationary bike is minuscule but there are hundreds of people sitting on the sidelines.  Plus imagine the side benefits.  The folks would get some exercise, and possibly be too out of breath to curse at the referee.  The kids would be thrilled not to have their parents shouting at them.

Think this is impractical?  Seems there are several devices like this in the market that can be plugged into regular bikes with the rear wheel raised on a stand to make them into stationary bikes.

"Nah none would use it!" you say.  Well how about giving them some motivation.
We could pit parents of the two sides against each other and even have a power meter indicating which side is generating more power.  Thus while the kids play peacefully in the middle, parents can duke it out constructively on the sidelines.

What if the soccer facility provided the bikes and parents would swipe an ID to register themselves and their energy production could be tracked and they would get back some credit?  This system already has been imagined for bike rental systems here.

Any takers?