No need to tread lightly: the tile lighting up football in Rio and stations in France

Whenever a goal is scored on the community football pitch at the Morro da Mineira favela near central Rio de Janeiro, the crowds can cheer on courtesy of the six unique – and newly installed – floodlights.

But what makes these lights distinctive is that they are partly player-powered.

Rows of kinetic tiles beneath the astroturf capture the energy of the players during the day as they run from one end of the pitch to the other; the energy is stored and fed back into the floodlights between 7pm and 1am.

Pavegen, the company behind the tiles, is the creation of Laurence Kemball-Cook. The 29-year-old designer came up with the idea six years ago when making his way among the throngs of commuters passing through Victoria station in London.

Shortly before, Kemball-Cook had been on a placement year from his industrial design course, working on a project with the firm Eon to power street lights by solar or wind energy. By the end of the year, the project had petered out after both options proved unworkable. He returned frustrated to his course at Loughborough University – until his eureka moment at Victoria.

“I thought about … tapping this resource [footsteps] which hasn’t been channelled before,” he says. “I thought what if we could have a tangible energy solution which would be retrofitted easily, that would have a good power app that you could actually use but, most importantly, give you power when and where you need it.”

From that early spark of inspiration has come the Pavegen tiles, 5cm-thick units which have already been fitted in railway stations, universities, schools and offices to harness the energy from footfall which is then stored in a battery and can be used within a 200-metre radius to power street lights or charge mobile phones, among other uses.

The way of achieving this, says Kemball-Cook, is to use some “really wacky geometry and some really wacky combinations of engineering principles” which centre around the use of a flywheel to store the energy.

“A footstep is a really quick impact and the problem with the people who looked at it before is that it is such a quick impact, every single step, that it is really difficult to harness that power in a useful way. What we managed to do is convert a quick impact into continuous power.

“So long as people keep walking on our tile, we always have power output. We do that through … [storing] energy in a flywheel. The inertia of a flywheel spinning holds the power as people keep walking on it,” says Kemball-Cook.

When someone walks on the waterproof units, their foot compresses the tiles by about 5mm – a similar feeling to walking on a playground or a running track. Continuous steps give a few seconds of power which is then stored for use later. In an area such as Oxford Street in London, where there is a very heavy footfall, 10 tiles around a street light will power it through the night, he says.

“In high-footfall environments, as long as you have a footstep every 10 seconds, you will be getting a continuous output from people walking on it,. Typically [in] a busy high footfall environment you get a footstep every two seconds. So imagine an office environment between 8am and 9am: it is going to be at its peak. That peak, you are going to get a constant on, like turning a switch on, and then it will drop off in the afternoon but we have accumulated the energy from the morning to power for the afternoon.”

The market for the tiles is split between events, such as at the finish line of the 2013 Paris Marathon where the energy was gathered from 40,000 runners, to more permanent uses like at Heathrow airport where it is used to power lights along a corridor. Outside the Saint Omer train station in north-east France, 14 tiles harness the energy from commuters which is then used for USB ports in seating to power electronic devices.

The tiles can be topped with materials such as vinyl, carpets and rubbers. The ultimate aim is to get the price down to the level of conventional flooring within three years.

According to Kemball-Cook, the tiles cost £20,000 a sq metre to produce in the early dies, but this has already come down to £1,250. He aims to have this reduced to about £50 a sq metre, less than the cost of luxury carpet, and to reduce the thickness of the tiles to less than 5mm, the same as a carpet underlay.

An initial plan in the early stages to have a light in each tile was binned after women thought there was a camera looking up dresses and skirts.

“They will be hidden under everyday roads and everyday buildings and normal floors. That is the end game,” he said. “We will be like the Intel Inside on a PC – the Pavegen inside on a floor.”

The company has made revenues of £5m since it was launched in 2009 and is in profit, according to Kemball-Cook, with investment so far of close to £1m. He remains the majority shareholder of the company.

Beyond the immediate use for generating energy, the company is also developing ways of gathering data for crowd management – such as when large crowds are expected in areas so that staffing and cleaning can be organised. Another area is security, where the tiles would act as an alarm system which does not need a battery.

“In the future a floor is not just going to be a floor, it is going to be a portal to engage with the smart home using the direct impact to send signals and identify people,” he said.

It is not just feet

Among the other uses being worked on for the Pavegen system is a speed bump that could be located in a car park or on a slip road. Kemball-Cook says there is the potential to create substantially more power from cars as the minimum weight is about 1,000kg for a vehicle compared twith 70kg for a person. The car has two axles so would be going over the bump twice, creating more impact, he says.