Charging EVs from bumps in the road - Part two

In our article More Power from Bumps in the Road we described work at MIT on energy harvesting shock absorbers where one such device on a truck can generate as much as one kilowatt electrodynamically. However, bumps in the road can also help to recharge EVs in this case by providing power to roadside charging points. Early work on this involved flaps in the road electrodynamically generating electricity where the vehicle had to slow down anyway as is the case at a gas station. Now a more elegant version of this has arrived.

 

The James Dyson Award is an international design award that celebrates, encourages and inspires the next generation of design engineers. It's run by the James Dyson Foundation as part of its mission to inspire young people about design engineering and this year's winner will be announced on the 3rd August.

 

One of this year's entries is designed to harvest the energy from traffic moving on roads. The designer found inspiration when noticing a car drive over a Cat's Eye which depressed into the road, and realising that this energy could be put to better use. The resulting design is a rubber road rib that senses vehicles passing over it and generates electricity from the motion.

 

 

 

 

Using a mechanical system would mean the ribs would be weak so the main development made was to design the rib to be completely self contained and remove any moving parts. The design is a single rubber housing which contains two strips of magnets and a configuration of induction coils. The specific rubber is a 45 shore hard natural rubber which is extremely durable and flexible so allows the rib to function as it is designed to while being able to withstand the heavy loads and impact of passing vehicles. The shape of the internal detail means the coils are never moving parallel to the magnetic flux therefore giving the rib as high as possible induction potential. A further and very important point is its positioning on roads; it is to be placed in braking zones where vehicles should no longer be accelerating. This means any energy taken from the vehicle is not wasting fuel but assisting the vehicles' retardation. A number of other design developments include the use of neodymium magnets, wedge side detail for securing the rib in the road, the cushioning underside detail and flexi-pockets.

 

The idea is that this energy can be stored in a roadside battery and can be used to power any electrical roadside device or electric vehicle charge points. It seems that variants on the bike dynamo have a long way to go.