This type of devices include all kind of equipment which, through any human capability like muscular power , temperature, weight , size, etc , can generate electrical energy to perform a work or ,through mechanical systems,  have equivalent work as it were powered by electrical energy.

World population is growing so, we can start thinking about the possibility all the energy/heat which can be obtained by any human contribution.

There are endless applications and some external links:

If you are able to do anything of the above list or you use the human boy on any mechanical/thermal application , then you have a human powered device.

Applications include pedal powered devices which can be used in education, emergency situations, for power outages and off-grid applications and to power laptops, grinders and water wells