By Michael Kern
One odd, energy-related fact that came out of the Yugoslav wars was the phenomenon of the “Designated Electricity Maker”.
With no power in the cities, the only way to get it was to pedal, which usually meant spinning a custom-rigged bicycle hooked up to a car battery.
Whether you wanted to vacuum or host a war-time party, it all required a “Designated Electricity Maker” who wasn’t allowed to stop until the floor was clean or there were no more requests for music.
Decades later, a Netherlands-based company called Energy Floors launched the “Sustainable Dance Floor” project, designed to turn clubbing into an experience that would be useful, beyond socializing.
In 2008, Dutch inventor and artist Daan Roosegaardechose installed his invention at the WATT club in Rotterdam, a city where over 10,000 people go out clubbing each weekend.
The “sustainable nightclub” helped the port in Rotterdam, Europe’s largest, to reduce its emission.
A system was installed under the dance floor to convert the pressure exerted by the dancers’ steps into electricity that powered the club’s lighting and DJ booth. The generator consisted of 65-centimeter-square modular units, each producing 25 watts of electricity.
When compressed by dancers, the system produces an electrical current. This current was stored in batteries and then consumed.
The kinetic energy generated by dancing, or any other human movement, can be harvested using piezoelectric technologies.
Piezoelectricity is generated in certain crystals that produce a current when squeezed, or in response to compression force. Such crystals are often used in audio equipment to turn sounds into signals or vice versa, but if enough of them are placed together, they can do much more.
It was a brilliant idea that didn’t last very long in Rotterdam, and Club Watt has since closed down.
In 2012, the Sustainable Dancefloor generated over one million joules, or one ‘megajoule’, in a single evening at a nightclub in Murcia, Spain. Another key European city in terms of nightlife city, Berlin, won support from the authorities, who pledged to finance the Sustainable Dance Floor.
Since then, ‘Energy Floors’ have evolved beyond clubs and into all sorts of venues that seek to generate power from human movement anywhere from school playgrounds to high-traffic walkways.
Early Days of Human Movement Harvesting
From piezoelectric roads, still under development, to harvesting body heat from crowded urban facilities, the potential for humans to serve as a source of energy is a growing obsession in this era of extreme waste and climate change fear.
The basic premise is this: We’re wasting a ton of energy by failing to capture the energy from objects in motion, and piezoelectric material is one way to absorb that wasted mechanical energy and convert it into electrical energy.
Some believe it is the next-generation answer to power. The crystals that make this work are naturally forming both at the surface of the Earth and deep within, and they include clear quartz and amazonite. But there are also artificial crystals formed by chemical compounds, such as Barium Titanate, Lead Titanate and Lead Zirconate Titanate, according to a 2016 research study.
One application of the idea is being studied for roadways, with the resulting power generation used in street lighting. Piezoelectric crystals under the asphalt would generate electricity from the pressure of vehicle motion above, while the electricity would be stored in batteries and used to operate street lights.
Energy Harvesting: It’s Going Commercial
The growing adoption of consumer electronics alone is spurring steady growth in market share for energy harvesting equipment solutions. The ‘sustainable dance floor’ was just a playful beginning.
Harvesting energy from body movement is part of this market share, and wearable sensors will likely dictate where this goes from here, particularly because of the power of the massively expanding market for wireless sensor networks.
In 2017, South Korean scientists developed an energy-harvesting clothing sensor that generates energy from ambient heat.
And earlier this year, Rice University unveiled a laser-induced graphene nanogenerator that could power future wearables.
This is where it all might get practical.
Led by chemist James Tour, the Rice lab has adapted laser-induced graphene (LIG) into small, metal-free devices that generate electricity that could potentially power devices.
It’s the same principle, more or less, as the ‘sustainable dance floor’.
The experiments used a folded strip of LIG that was connected to a string of light-emitting diodes. When they tapped the LIG string, it produced enough energy to make the lights flash. They also experimented on a larger scale, using a human being in flip flops to generate energy by walking with a larger piece of LIG attached to the flip flops. Every time the wearer’s foot hit the LIG strip, it produced a current to charge a small capacitor.
“This could be a way to recharge small devices just by using the excess energy of heel strikes during walking, or swinging arm movements against the torso,” Tour said. POC and Swedish Exeger are also partnering to develop helmets that create “endless power” by converting light energy into electrical energy. The project seeks to enable smart tech integration into wearable helmets using unique carbon positive material that converts light into electricity.
No one’s seen the helmet yet, but the material looks like this:
The material is said to harvest both artificial and natural light – so it’s creating electricity and recycling electricity, ostensibly. They plan to release the next generation of the helmets next year already, and future plans include integrating the same energy harvesting material into wireless headphones and tablets.
In fact, Exeger envisions personal electronic devices that almost never need to be plugged in.
The undeniable fact is that next-generation power is moving in the direction of self-generation, and most likely, it’s going to be wearable. And the driving forces now more than ever are climate change and mass adoption of smart devices.
Make no mistake: We will eventually be wearing our own electricity.