Traffic energy recovery systems promises free electricity

Drivers waste a lot of time in traffic, and also energy.

Every time they come to a stop, the force exerted by their brakes generates tremendous amounts of heat energy that simply vanishes into thin air.

Hybrids and electric cars try to recapture some of this in the form of electricity by using their motors as generators as they slow down, but these account for less than 5 percent of vehicles sold each year, and the process isn't 100 percent efficient. A Chicago company called New Energy Innovations is looking to harvest some of that lost energy with its Traffic Powered Renewable Energy System, or TPRES.

New Energy Innovations is not the first to try to tackle the concept, but its patented system is unique. Company founder Ralph Black describes it as a series of cartridges fitted with vertical pumps, similar in design to a stand-up bicycle pump. They're buried in the road surface inline and connected by a 1.5 to 2.5-inch high bar covered by a flexible membrane that compresses the pumps as cars roll over it. The air is collected in a roadside tank then sent at a constant pressure to an air motor that runs a generator, which can power things directly, charge storage batteries, or feed it into the grid.

TPRES is currently being developed in collaboration with the University of Illinois at Chicago Mechanical and Industrial Engineering Department, and New Energy Innovations hopes to demonstrate it on a real road in the city of Elmwood Park this summer. Black says the goal is to make it low and smooth enough to be less obtrusive than driving over a railroad crossing, while also keeping costs down.

Black envisions TPRES being installed in the braking zones approaching intersections and toll booths, where he says 10,000 cars could generate up to 1200 kilowatt-hours of electricity daily, enough to power around 40 homes.

More likely, some of that will be used to run the surrounding street lights or toll booth station, reducing energy costs and allowing them to continue operating during power outages. Exact pricing hasn't been determined, but it could be as low as $100,000 per installation, and New Energy Innovations has targeted a 4-year return on investment through energy savings.

The company is planning a crowdfunding campaign to help get TPRES off (or maybe it's into) the ground.