Lots of people need cardio exercise to keep their health up, and few get paid for doing just that. Here's a way to get people active, pay them, and save the environment at the same time. Using pedal power, lets think up ways to make use of this energy to produce electricity, and pass the revenue from selling this electricity back to the pedal pushers.
There are at least two different ways that pedal power can be put into practice. One is through the spinning of heavy devices that in turn drive turbines that produce electricity. The second is using the pedal power to pump water from a bottom pit to a top pit and as the water falls with gravity to the bottom pit, capture the power of that water falling.
There have been a few attempts documented on-line as to how using a bicycle to generate power is an interesting project, but not productive enough to be taken seriously. Google bicycle power generation and you'll see that many attempts have been made. What I have in mind is the next level of power generation.
With the number of transport trucks out on the roads, there are bound to be stock piles of axles out there that are no good any longer for transport, but still good for this idea. With the tires filled with water, or filled with air, with all four tires intact, with a proper gear system in place to drive this axle, the momentum carried by the heaviness of the four tires would be sufficient to drive a heavy generator and produce sufficient electricity to make this a profitable venture. Electricity production is in a large part a function of the speed of the turbine being spun, so in this case a solid gear system could make it so that these heavy axles spin at a high speed. One idea is that if the axle is already spinning at it's maximum speed and the cyclist is done for their workout, if a new cyclist is ready to start, they can take the place of the previous one before the axle loses much momentum. In this way startup in the lower gears is no longer necessary. For starting from the lower gears some amount of manual assistance in starting the axle would be necessary.
In this setup the amount of KwH produced could be tracked by cyclist, and the cyclist could be paid a rate per KwH.
With a large reservoir of water which is raised up, with a large reservoir below it, water would flow down and turn the turbines producing electricity and would be pumped back up again by the cyclist(s) who are getting their workout. The rate at which water would be let down from the upper reservoir would be electronically controlled to match roughly the amount of water being pumped back up again by the cyclists present. In this way the water levels of the upper and lower reservoir would never be too empty or too full. In this setup the way to measure how cyclists would be paid would be how much water they are able to move from the lower reservoir to the upper one and to match that to an average of how the water produces electricity
In either case of the two different setups mentioned above, there would be a facility involved. This facility would include a number of cycling stations, a locker room with showers, a few large movie screens with ear-phone jacks at each cycling station to let you select which screen you will be listening to, and a tracking system at each cycling station to keep track of how many KwH you've produced, or how much water you have pumped. There could also be a leaderboard which shows the name of the person who has earned the most money in the last day, week, month and all time.
Some amount of marketing effort would be made to get as many people signed up to this service as possible. The amount of money received by the sales of electricity would have to pay for maintaining the facility (heating, lights, taxes, etc) and what is left would have to go to the cyclists. As a result there wouldn't be enough income for someone to earn a living if they were capable of cycling full time. This service is to supplement your income if you should be exercising. Why spend money to go to a gym when you can get paid to cycle? The more people that can be hooked by this question the more profitable the facility will be. Since the facility costs are fixed, if enough electricity is sold to meet the facility costs and still there are more days left in the month to produce electricity, the rate at which the cyclists can be paid will go up, so the more cyclists there are, the more each of them will be able to earn.