Good Vibes Used To Power Rail Infrastructure

You think about a train and its energy use, and you think about the diesel or the electricity used to power the train itself. But there’s a railroad infrastructure that goes along with that, and researchers at Stony Brook University in New York have come up with a clever, clean way to keep things like signal lights, crossing gates, track switches and monitoring sensors working.

It’s called a mechanical motion rectifier, and it uses the vibrations that a rumbling train sends down the track.

Inventor Lei Zuo from Stonybook said the device can grab “200 watts of electric energy from train-induced track deflections to power the track-side electrical devices.”

Rectifiers convert alternating current, which periodically reverses direction, to direct current – so that gives you a sense of how this kinetic energy technology works.

“By using two one-way clutches, the innovative mechanical motion rectifier converts the irregular up-and-down vibration motion into unidirectional rotation of the generator, thus breaking the fundamental challenge of vibration energy harvesting and offering significant advantages of high efficiency and high reliability,” Zuo explained in a press release.

Zuo said the invention could be particularly useful in the United States, because the country’s 140,700 miles of rail tracks often traverse remote areas, which makes powering track-side electrical infrastructure especially expensive.

For his efforts, Zuo – along with graduate students Tin Lin and John Wang – this month won the “Best Application of Energy Harvesting” award at the Energy Harvesting and Storage USA 2012 conference.  This comes on the heels of Zuo winning an R&D 100 award for a similar invention – “retrofit energy-harvesting shock aborbers that convert vibration, bumps and motion experienced by the suspension of a vehicle or train into electrical power.”

Zuo has also worked on vibration and thermoelectric energy harvesting systems that use ocean waves and even tall buildings as sources.

According to the university, the technology behind the the “MMR based Railroad Energy Harvester” has been licensed to Electric Truck/Harvest NRG, an early supporter of the project. Support for the research also came from the U.S. Department of Transportation’s University Transportation Research Center, New York State Energy Research and Development Authority, SUNY Research Foundation and private industry, the university said.

Pete Danko is a writer and editor based in Portland, Oregon. His work has appeared in Breaking Energy, National Geographic's Energy Blog, The New York Times, San Francisco Chronicle and elsewhere.