Piezoelectric road harvests traffic energy to generate electricity
By Mike Hanlon
December 14, 2008
Isreali engineers are about to begin testing a 100 metre stretch of roadway embedded with a network of Piezo Electric Generators (IPEG™). The piezoelectric effect converts mechanical strain into electrical current or voltage and the system is expected to scale up to 400 kilowatts from a 1-kilometre stretch of dual carriageway. The IPEG™ is a pioneering invention in the field of Parasitic Energy harvesting and generates energy from weight, motion, vibration and temperature changes and will certainly have other parasitic energy harvesting applications in many fields. Initially though, the system can be configured to generate and store energy from roads, airport runways and rail systems at the same time as delivering real-time data on the weight, frequency and spacing between passing vehicles. The harvested energy can be transferred back to the grid, or used for specific public infrastructure purposes such as lighting and widespread use of the system would enable far greater scrutiny and hence understanding of the behaviour of road vehicles.
Isreali engineers are about to begin testing a stretch of what may become the road of the future. The road contains piezoelectric crystals that produce electricity when squeezed, enabling them to harvest some of the energy which vehicles lose to the environment during their journeys. The system is expected to produce up to 400 kilowatts from a 1-kilometre stretch of dual carriageway and the technology is also applicable to airport runways and rail systems. In addition to being able to produce its own power, the system can also deliver real-time data on the weight, frequency and speed of passing vehicles as well as the spacing between vehicles.
As such, the embedding of piezoelectric generators to create "smart roads" could eventually become an integral part of traffic management systems. The Piezo Electric Generator (IPEG™) developed by Isreali University spin-out company Innowattech has the ability to harvest energy from weight, motion, vibration and temperature changes and as such it is a pioneering invention for Parasitic Energy harvesting. Innowattech has refined specific configurations of the IPEG to create high efficiency generators from roadways, railways and airport runways.
The harvesting system of parasitic mechanical energy from roadways is based on the piezoelectric effect converts mechanical strain into electrical current or voltage. The harvested energy can be transferred back to the grid, or used for specific road infrastructure purposes. The infrastructure captures and stores energy for reuse.
The company is developing a wide range of Piezoelectric generators with sizs varying from a few centimeters to networks covering large surfaces. The generators are embedded between the superstructure layers, and usually covered with an asphalt layer.
The generators are mounted with electronic cards supplying the storage system. The laying of the present system, (embedding the generators and electronic cards in to the roadway), can be done during paving of new roads or in the course of the maintenance work in existing roadways, so it’s entirely retrofittable to any road, and the heavier the vehicle, and the greater the number of vehicles, the greater the return, all the way to electricity production on an industrial scale.
This means that parasitic energy of busy roads, railroads and runways near population centers can be converted into electrical energy that can run public lighting, or fed back into the grid.