SXSWorld
Issue link: https://sxsw.uberflip.com/i/528894
4 6 S X S W o r l d | M AY / J U N E 2 0 1 5 | S X S W. C O M very day, millions of us pound the pavement. If we could cap- ture just a fraction of this energy, say proponents of kinetic or "biomechanical" energy, we will stride through life as min- iature power stations, saving the planet with every step. It sounds great, but can our bodies really make a meaningful con- tribution to our own daily energy needs, let alone the wider world? One of the biggest players in the field is Pavegen, winners of SXSW Eco's 2014 Place By Design competition, whose proprietary tech- nology is a paving slab that generates electricity from footsteps. "Our vision is to deploy the technology on scale to all high foot- fall locations, such as transport hubs, retail sites and entertainment venues around the world," explains Pavegen's Head of Business Development, Jonathan Keeling. "Our intention is to target devel- oping countries around the globe, and provide them with a cheaper alternative to have access to electricity, especially within areas where solar and wind alternatives are not feasible due to high-rise infra- structure and pollution." The company has been involved in numerous brand collaborations, as well as such headline-grabbing projects as an installation at the 2012 London Olympics and a soccer pitch in a Rio de Janeiro favela that powers the surrounding LED floodlights. They're the kind of projects the media loves, but there's a difference between powering a branded promotional display about saving the planet and actually saving the planet. The Rio project, for instance, employs solar energy in addition to the tiles. The Olympic installation, meanwhile, only generated enough power to charge 45 cellphones. It only featured 12 tiles, to be fair, but even scaling this up begs the question of whether the output is worth it. "Oxford Street in London provides an example of an ideal location to install our technology," argues Keeling. "It is 1900 meters long and has an average footfall is 130,000 pedestrians per day – this will produce at least 125 MegaWatts hours per year if we harvest only 3J per footstep. With our technology there is the potential to harvest more, but this alone could power 30 average U.K. homes for a year." However, when you consider that one single average-sized onshore wind turbine can power 1,500 homes, marketing kinetic energy as a viable addition to the large-scale energy mix doesn't quite add up. A possibly more realistic voice in the debate comes from Adam Boesel, who set up and sold two successful eco gyms in Portland, Oregon. He now focuses on helping others go green by providing exercise bikes that generate power as you pedal. With a focus on edu- cation and experimentation, he believes that kinetic power devices are best used in place of equipment that actually draws power. "I think it's best used in fitness and education," he explains, "where not only are you interacting with it, but learning the (some- times hard) truths about your capability to generate – as well as how much we take it for granted." To prove his point, a video on his website shows a fit-looking guy contributing power to a plugged-in Nissan Leaf. Even at full tilt – a pace a lot of people couldn't reach, let alone sustain – the effort only adds a fraction to the car's needs. So is kinetic energy a non-starter? Crucially, it depends on what you're powering – and where. While it shouldn't be seen (or sold) as a solution to large scale energy problems, "people power" has already found useful applications in remote, micro and mass utilisation. As campers who own wind-up radios and shake-to-power flash- lights know well, it's perfect when you're in the middle of nowhere and need power. Taking this to the next level, the U.S. military is experimenting with leg braces, backpacks and other devices which capture kinetic energy to charge radios and other electronics – useful on remote battlefields, especially when soldiers are already carrying heav y weights which add to the potential energy captured. In the longer term, new technology could make kinetic power more seamless – and that's where things could get interesting. Professor Zhong Lin Wang of Georgia Tech is working on a series of new devices to harvest kinetic energy from the tiny motions of our bodies, our clothing and even our fingers tapping on screens. This raises the possibility of self-powered electronics, and a vast ocean of tiny power-collecting devices plugged into the long-awaited Internet of Things. "Traditional harvesting technology uses piezoelectric effect," explains Wang, which he points out is "high cost, relatively low effi- ciency and sometimes difficult to fabricate. A recent breakthrough is to use the triboelectric effect to convert mechanical energy into electricity by a conjunction of triboelectrification and electrostatic induction." Harnessing this power – the stuff that makes sweaters crackle with static – could help power our laptops, tablets and per- sonal devices. At this point, whether kinetic energy is a viable green power option, even on a small scale, is still undetermined. In the mean- time, investing more money and public enthusiasm in less sexy but more heav y weight projects like building insulation, wind and solar remains crucial to meeting our ever-growing energy needs. C hris Hathe rill is the fou nde r of su p e r/coll i de r. A p p l ica t io n s fo r SX S W Eco 20 1 5's Sta r tu p S h owca s e a n d Pla ce B y D es ig n co m p e t it io n s a re d u e b y J u n e 26. F o r m o re i nfo rm a t io n , v i s i t s x s we co.co m . Power From the People: Can Kinetic Energy Become a Viable Resource? by Chris hatheriLL E Th e S h el l Fo ot b a l l Pitch in Rio's M o rro d a M in eira fa vela C O U R T E S Y O F S H E L L