At first for someone who talks about the the big energy systems, looking inwards and finding ways to extract energy from the human body is something different except for the fact that it is indeed renewable by default. I have been challenged in doing this by the Sustainable Future Challenge. If you happen to see this at the same level as me, you could probably be excited at the opportunity of doing something different or radical. There is a sense of excitement when you sit down with your team and brainstorm ideas. An approach that focuses on looking at the problem and trying to find a solution that could work is exhilarating. But, the excitement dwindles down the moment you hit google to find if anything remotely to what you thought of has been attempted.
Well, you would be surprised to see most of what you spoke about have already been attempted. I have to confess that I’m aware of certain ideas that have been tried or is working currently that is related to what I was thinking off. But, a few ideas, I never expected to see them.
So, here I am with a summary of some cool ideas that harness the human energy. The early ones are something you are aware of by now, but the best is in the end. The list excludes the medical implants which for a few years now have been designed to be powered by human energy within the body.
Before we start how much energy do we have? A quick look
You would have heard about the energy generating shoes by now (More info)
Have you danced on a floor that generated its own energy? (More info: Energy Floors)
Generating Energy from the human heat (More info)
Seiko apparently was the first firm to develop Seiko Thermic a watch that ran on energy generated by temperature difference. (That is not available now)
A backpack that generates energy while you are walking (More info)
If you thought all this was novel and cool, please beware; Energy from blood (Read more)
And what about breathing? There is a novel prototype already. (Read more)
In this industry the most innovative company that I have been following for quite some time is Pavegen, check out their latest success story in building a stadium powered by human energy.
How about Sound? Well, this isn’t entirely an energy generator but this device uses sound to save energy. Its called the VOCCA smart light.
And finally if at all I believe that human energy has immense potential when coupled with human ingenuity Gravity Light is the answer. This awesome products is a winner at all levels. It won the shell springboard award for the best innovation. It leverages the human strength to put things at height and the rest is gravity. Enjoy the video and the innovation!
Back to the start, our search for the untapped human energy still continues. If you have any idea or suggestion do get back to me. Your inputs will be invaluable.
If you want more dosage of the possibilities do read on link1, link2.
Mission Shunya 
I love the gravity light. I’m less sure about some of the others. I’d like to know when the carbon cost of creating them will be repaid, and whether there isn’t a better solution. For example whether a bike with a generator (100 watts per bike) isn’t rather more carbon efficient than a pitch that absorbs energy. That’s why I think carbon accounting is so important.
I agree to the point on carbon accounting. But I also believe the carbon accounting has to include the carbon offset in terms of energy not consumed from the grid.