Engineers in Great Britain have developed a means for recovering energy from car exhaust. The researchers call the system a Turbo-generator Integrated Gas Energy Recovery System (Tigers) and speculate that it may cut fuel consumption by as much as 10%.
“This is a really exciting development. Up to a third of the power that a conventional engine produces is wasted as exhaust gases. By harnessing some of that power we can make the engine more efficient,” says Richard Quinn of Visteon, one of the engineers affiliated with the Foresight Vehicle initiative.
The untapped energy source is not the spent fuel itself, but its swift movement through the exhaust system. Car exhaust can become as hot as 800°C and, near the engine, can move at a velocity of 60 meters per second. The Tigers device uses this high velocity to spin a generator at up to 80,000 revolutions per minute.
The resulting electrical power, according to Quinn, would be sufficient to produce up to 600 volts, enough to operate an average-size car’s heating, lighting, air-conditioning, and entertainment systems.
By eliminating energy loss, fuel consumption could be reduced by between 5% and 10%-not just in vehicles, but in many other applications, as well, according to Quinn.
“In a hybrid electric car, the Tigers device could feed the extra power directly to the drive motors or back to the battery to increase the range of the vehicle. On commercial vehicles, the extra electricity could be used to power electrical systems to run refrigeration units for chilled food, turn the motors on cement mixers, or power pumps on fuel tankers,” says Quinn.
The recovered power could also be used to run advanced engine technologies and processes, including electromagnetic valve actuation, which could make vehicles lighter and more energy efficient, and electric exhaust after-treatment, which could make for cleaner emissions.
The researchers suggest that the excess energy harvested from the Tigers could also increase performance in other as-yet-unexplored ways. For example, when the exhaust velocity is high, the excess energy could be stored in a battery for later use during low-exhaust cycles.
Americans waste approximately 27 million gallons of gasoline each day simply idling in traffic. That’s enough gasoline to fill 134 super tankers. At $3 a gallon, that also equates to $800 million a day wasted due to inefficient energy use. The Tigers device could reduce those numbers while improving air quality. The researchers plan to have a fully operational prototype ready for bench testing before the end of 2006.
Source: Society for Motor Manufacturers and Traders, Industry Forum, 2410 Regents Court, The Crescent, Birmingham Business Park, Birmingham B37 7YE, United Kingdom. Telephone +44 845-009-3838; Web site http://www.foresighvehicle.org.uk; e-mail doug.Wallace@impactpr.co.uk.
Originally published in THE FUTURIST, May-June 2006.