We all know that walking is one of the most, if not the most, environmentally friendly means of transportation. What if you could help power the world around you just by walking? If you are picturing yourself like a hamster on a wheel you’ve got the wrong idea.
Hailing from the United Kingdom, Pavegen produces paving tiles that can be placed in high traffic areas and harness pedestrian energy. Pavegen units are constructed to endure the elements and pay for themselves in about a year. Over an expected five year lifespan the units can provide electricity to surrounding kiosks or power lights at a transit station.
Pavegen tiles are available in a variety of colors but the use of green tiles sends a strong environmental message. When a pedestrian steps on a Pavegen tile, the tile moves no more than 5mm (25.4mm = 1 inch). The kinetic energy of a footstep is used to produce electricity.
Basic physics shows that the person stepping on a Pavegen tile will exert more energy to depress the tile and create electricity than if they were to step on a conventional flooring tile or sidewalk slab. The efficiency of the human body certainly plays a role in an electricity produce by a Pavegen system. It is true that carbon based fuels and petrochemical based pesticides and fertilizers are the norm in global food production and food is the fuel the body uses to produce the footstep to power a Pavegen device. Without doubt, greening of the global food system is a desirable goal but the fuel powering a Pavegen system is not fuel that is being consumed in addition to what a person would have eaten anyway.
Conversely, if a Pavegen style solution were applied to motorways, the resulting electricity would be inefficiently produced. Inefficient because it will take more fuel to propel a vehicle over the system than over conventional pavement. Additional emissions would be released and at best the same amount of energy put into the system would come out of the system.
To put this more simply, remember that energy is neither created nor destroyed. Energy is essentially converted from one form to another. Inefficient systems are said to be wasteful but they merely convert energy into a form other than the desired output. The easy example of this is a lightbulb. When a lightbulb is electrified the desired result is light. The inefficient result is heat.
A Pavegen style system on a roadway would require more energy input than the amount of energy output and the fuel is a carbon fuel adding to emission concerns. The human body may not be the most efficient system but Pavegen essentially harnesses pedestrian power that would otherwise have been expended without electrical gain. Pavegen may not be perfect but it’s certainly a step in the right direction.
Article by Adrian King, appearing courtesy Justmeans.