Humans spend energy for all the activities they carryout during the day.
In case a methodology is found to Harness this energy and recycle for public use could be a great sourse.
Since every moving human produces energy the COST v/s BENIFIT should be encouraging.
Now the avenues
1. Morning walk/Runs tracks
2. Staircase in every Buildings..Most of Young Do not Use lifts use staircases for exercise
3. Even Footpaths along the roads.
These can be fitted with suitable gen. sets and energy harnessed