“Parasitic energy harvesting” might sound like it is part of a Sci-Fi plot where alien beings feed off of the energy emanating from human bodies, but it is actually a means of reclaiming wasted energy. An Israeli company, Innowattech, says that it holds the patents to technologies that can harvest the mechanical energy from vehicles traveling on surfaces such as roadways, railways, and airport runways, and convert that energy to electricity. Not only does Innowattech have the technology, but it wants to implement it into our highway, rail, and airport infrastructures.
The technology “is based on piezoelectric generators; the piezoelectric effect converts mechanical strain into electrical current or voltage.” In other words, when a piezoelectric material is deformed, the energy from the deformation of the material gets converted into electricity. Innowattech has created three different versions of what it calls the Innowattech Piezo Electric Generator (IPEG): a Roadway Generator, a Railroad Generator, and a Runway Generator. Innowattech claims that its IPEGs can “harvest energy from weight, motion, vibration and temperature changes.”
While it might not be noticeable to the casual observer, whenever a vehicle passes over a roadway, the roadway actually deforms somewhat beneath the vehicle. If you have ever had your foot run over by a car, you have experienced a version of this–albeit, likely a painful one. The same thing happens to rail beds and runways when trains and planes pass over them–these surfaces deform slightly as well. Innowattech wants to implant networks of its IPEGs into these surfaces so that vehicles will also deform the piezoelectric generators as well, which in turn would generate electricity. In fact, the heavier a vehicle is and the faster it is moving, the more energy gets transferred to the IPEGs. Innowattech claims that 1km of a railroad can produce up to 150kW of electricity per hour; and 1km of roadway or runway can produce up to 0.5mW (500kW) of electricity per hour. The electricity harvested by the IPEG network could be added to local electrical grids.
The roadway and airport IPEGs can also “record the weight, frequency and speed of passing vehicles as well as the spacing between vehicles in real time.” This can create “smart roads” and airports where the data can be used to help manage traffic and alert drivers and emergency responders.
What makes this such an innovative approach is that it doesn’t force drivers or car manufacturers to have to make any significant changes, such as switching over to electric cars or other fossil fuel alternatives. By the same token, it makes no difference to the IPEGs what is powering the vehicles passing overhead, so as automobile engines continue to evolve over time away from fossil fuels, the IPEGs will continue harvesting their energy. It remains to be seen, however, if this “green” technology will ever see real-world applications.