POWER PAVEMENT: A new paving slab built from concrete and used tires can generate clean electricity for cities from footsteps.
Image: Lysippos/Wikimedia Commons
LONDON—It could be the last word in concrete solutions to carbon emissions: a paving slab that generates electricity with every footstep taken on it, providing clean power to both cities and remote areas not connected to a national grid. Best of all, it requires mainly used tires and concrete.
The invention is the brainchild of industrial engineering graduate Laurence Kemball-Cook, who came up with the idea, perfected it in his final year at Loughborough University in central England, patented it, set up his company Pavegen and is now busy taking it to the world.
"I was studying the built environment and looking at solar and wind energy. I realized it is very difficult to get nice payback models on PV [photovoltaic solar cells] in urban spaces -- you have got shading, planning restrictions -- and wind is not great, either, because you have got turbulence," he told ClimateWire.
"I left university, and the roller coaster started right there about two years ago. I started with about £50 in my pocket. We have gone through friends and family, high-net worth individuals, and now we have institutional backing," he added.
As with many inventions, the idea seemed simple -- the trick has been in putting it into practice and then fighting to take it to market. Each slab has a surface made of recycled truck tires and a base made of recycled polymer concrete.
From college hallways to battlefields?
So the start is with material that would likely have wound up in a landfill. Each footstep depresses the rubber surface by about 5 millimeters or a fifth of an inch. This, using a mechanism that Pavegen is loath to discuss, is converted into electricity that can either be stored, used immediately or -- in bigger installations -- transmitted to the national grid.
While Kemball-Cook didn't discuss it, scientists and inventors have been working with a phenomena close to what he's experimenting with since the middle of the 18th century. It is known as piezoelectricity, basically an electric charge that accumulates in certain solids, including crystals, bone and some polymers, in response to applied mechanical stress. The word is derived from the Greek verb piezo or piezein, which means to squeeze or press.
The U.S. Defense Advanced Research Projects Agency (DARPA) has made an attempt to power battlefield equipment by piezoelectric generators embedded in soldiers' boots; however, the initial project was dropped because, among other reasons, the boots were uncomfortable.
As Kemball-Cook describes his invention: "Every time someone walks on the slab, it converts the kinetic energy from the footstep into electricity, so it is an off-grid power solution within urban spaces and transport infrastructure."
"Ten slabs around a streetlight would power it all night long from the energy generated during the day. You can get 20 or 30 seconds of light from a small light fitting from one footstep. We are working on much bigger systems right now. Imagine covering Trafalgar Square with these slabs and harnessing all the electricity from the thousands of people who walk across it every day," he added.
The slabs are designed to be retrofitted in place of existing flooring and, being waterproof, can be used inside or outdoors. The power produced can be used to power lights, advertising signs, alarms, music systems or even recharging devices. Display models deliver a weak electric current to power light-emitting diodes (LEDs).
The first to jump on the opportunity of foot-powered lighting was Kemball-Cook's old school in Kent in southeastern England. In December last year, the school covered the floor of a corridor with the power-generating slabs, which light up the area, as the 1,100 pupils make a point of using the corridor as often as possible.
Gotta dance
And that was just the first step.
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12 Comments
Add CommentThat's a good idea.
Reply | Report Abuse | Link to thisIf they could develop something that generated electricity from frost heaves now that would be useful where I live.
Reply | Report Abuse | Link to thisWill steady pressure generate a steady current or does the current only come from an up and down footstep?
Reply | Report Abuse | Link to thisHow expensive to make these slabs?
Reply | Report Abuse | Link to thisSounds like this may be a good idea for roads or any kind of regular movement.
A clever use of otherwise wasted mechanical energy, and Green to boot. Hats off!
Reply | Report Abuse | Link to thisAn, not clever. Not clever at all. This idea just steals energy from the pedestrians. In no way is this energy "free". You are performing work and burning calories for each erg generated.
Reply | Report Abuse | Link to thisHow is that a problem? What other use would this work go towards?
Reply | Report Abuse | Link to thismaybe if they could do this in front of stoplights and take some of the energy from cars that would normally go to waste during braking, it might make sense (even the best hybrids and EVs use friction brakes a lot when decelerating rapidly OR when operating under around 7mph). The power a person can generate is miniscule really, but recovering waste energy to power the stoplight or something might be useful. Or they could just wire some solar PV on the stoplight to get it powered.
Reply | Report Abuse | Link to thisWay to go Sir! If they manage to pull 30s of light (on a LED I suppose) from a single foot step, that's not minuscule at all! If LED is maybe 5W, then for half a minute it needs ~40mWh.
Reply | Report Abuse | Link to thisMultiply that with thousands of people and thousands of steps daily, on a relatively busy street - that's 40kWh.
Hopefully the price is not astronomic.
I already see it installed in barns, in remote villages and having the live stock taking care of the light needs! :) A cow must make at least 5 times more energy 'per step' :)
In answer to jayjacobs only the up and down motion would generate a piezoelectric effect as first described by Pierre Curie.
Reply | Report Abuse | Link to thisI hope he does not waste too much of his life on this. He will at least learn some physics & business skills along the way. Better than studying numerology or aroma therapy I suppose :)
Reply | Report Abuse | Link to thisHi,
Reply | Report Abuse | Link to thisGreat innovation.
How can I help bring this to Kampala where we are grappling with unreliable street lighting?
Jude Lumala