Mass energy harvesting: the technology is coming, but how do we tell fantasy from reality?

I’ve written about impressive cleantech on this blog before. But when I discovered this Brazilian football pitch, everything else seemed to pale in comparison: when it gets dark, its floodlights are powered by the movement of the players on the field.

This is almost exactly the same principle as the body heat powered music player I introduced my last post with: as long as you keep going, it does too. Both inventions harvest the energy we produce in everyday life to power the things we use in our everyday life – it doesn’t get more sustainable than that.

I know, however, that this particular football pitch is just one expensive PR exercise from Shell. We are unlikely to see such football fields built on a mass scale anytime soon. The question is therefore how we can know when a cleantech project is more than just a flash in the pan?

For the self-generating pitch, there is no doubting that the idea behind the project is good. And it is this idea, and the effective technology that powers it, that are the driving forces here. Because even if the self-generating football pitches will be few, the tech can be used in a whole host of other settings.

The invention in question was created by the London start-up PaveGen, the graduate project of a 25 year old from Loughborough University in Leicestershire. PaveGen installs floor tiles that capture the kinetic energy from footsteps using the piezoelectric effect. According to the company, each step on the special tiles generates enough energy to run an LED street lamp for 30 seconds.

In addition to football fields in the slums of Rio de Janeiro, PaveGen has also installed energy harvesting tiles at Heathrow, in UK and US schools, in train stations around Europe and in Australian shopping centres. Their tiles could even be found at West Ham tube station during the London Olympics. This shows that the football field wasn’t just a one off from Shell, but part of larger developments within energy harvesting driven by PaveGen.

Mass harvesting of energy is one of the greatest untapped clean energy sources out there. Every day we walk, run, slam doors and climb stairs – actions that all create energy that, in theory, can be stored and used. We only need the technology to capture it on a mass scale.

And herein lays the challenge – because some schemes for harvesting energy are more realistic than others. Once you run the numbers, ideas like harvesting energy from keyboard strokes, for instance, look a bit silly. That’s why PaveGen’s work is so important. They are demonstrating how we can use clean technology to transform an inventive idea into actual, tangible results.

Another, more mainstream, example of tangible results is the regenerative braking system currently in use on the London tube. The newest trains are said to recover 20% of the energy they use by capturing the kinetic energy from braking.

Opportunities like this are all around us. We only need to use our imagination to find them: capturing wind and wave energy on-board boats, harvesting kinetic energy from concert crowds, recovering thermal energy from engines. They’re small contributions by themselves, but on a large scale they can be massive.

After I started pondering these ideas, I now seem to discover new, potential sources for energy harvesting every day, just walking around my neighbourhood. I may be a technology optimist, but I don’t know why we aren’t fitting generators on kids’ playground equipment, for instance. I know my nephews could generate a good number of watts in just an afternoon. And why aren’t there any stationary bicycle generators at my gym?

I don’t have the answers, but I do know that we need technological developments like PaveGen’s tiles to power these ideas and to separate those ideas that work from those that don’t.

Which untapped energy harvesting sources do you see around you every day? Do you think they will work?

Images from PaveGen, CBSNews.com and Brixtonbuzz.com