A low-cost system capable of using traffic flow to generate electric energy could soon be used to light up cities in the developing world.
Mexican entrepreneurs have developed a system that captures the gravitational force of moving cars as they pass over a ramp in the road that uses the cars’ weight to create compressed air that in turn drives a turbine to generate electricity.
While there is an English patent for a similar idea using piezoelectric materials, which generate electricity in response to applied mechanical stress, in the road surface, inventor of the system Héctor Ricardo Macías Hernández says this would be too expensive for developing countries.
“This is a technology that provides sustainable energy and could be implemented at low prices, since it’s a complement of already existing infrastructure: the concrete of streets and avenues,” he said.
The technology consists of a ramp-step made of a polymer similar to that used to make tires that rises 5cm above the level of the street. When the ramp is pushed down by the weight of a vehicle it compresses a set of bellows.
This air passes through a hose to a tank where it is compressed and before being used to drive an electricity generating turbine.
Macías Hernández said that as the accumulation of electric energy is proportional to the flow of cars over a determinate spot, in places with low vehicular flow, several ramp-steps could be placed to multiply the impact of each vehicle.
The technology could also be implemented in places with high pedestrian flow like the subway, according to Macías Hernández, as people’s footsteps could also generate a significant amount of electricity in places.