February 23, 2012. Copyright 2012, Graphic News. All rights reserved

Flywheel technology, developed in racing, will reach cars via buses
By Neil Winton

LONDON, February 23, Graphic News:  Motor sport used to claim that it was more than just fun for the rich. Efforts to improve engine performance and handling would often percolate down to cars bought by real people.

Technology became almost too effective, and computerised devices took much of the skill away from the pilot, so racing cars were often stripped of new applications because it ruined the spectacle. Racing lost its claim to be crucial to technology development. But the need to improve fuel economy is inspiring new research. Grand Prix specialist Williams Racing is using flywheels not only to improve power with less weight, but raising the bar for fuel economy in ways that will move from racing cars to buses, and eventually to your next family car.

Williams Hybrid Power (WHP) is testing flywheel technology in a specially adapted sports car, the Porsche 918 RSR hybrid, which has performed well at high-profile races at Laguna Seca in Monterey, California, and the Nuerburgring circuit in Germany. The 918 RSR uses electric flywheel technology to store power as it spins at up to 60,000rpm, which can then be unleashed for overtaking, or stored to extend range. Some Formula 1 cars use a variation on this technology. The Porsche uses a conventional engine to drive the rear wheels and electric motors to power the front ones. WHP's flywheel technology uses composite materials developed in the nuclear power industry's high speed gas centrifuges to recapture energy as a vehicle free-wheels or as the brakes are applied, which is returned to the racing car's battery to use later. WHP reckons this technology is well suited to bus, tram and light rail vehicles, and what it calls "niche automotive sectors" like upmarket sports cars and SUVs.

"Instead of chemical energy storage as in a battery, a flywheel stores rotational energy that increases as the flywheel spins faster and decreases as the spinning rotor slows. An electromagnetic coupling between the high inertia rotor and a central non-spinning "stator" enables the conversion of electrical to rotational energy, and back," says WHP.

WHPs' technology, developed in the Kinestor project led by engineering consultant Ricardo, improves on previous flywheels by using magnetic gearing and coupling, and eliminating a drive shaft. This allows the system to be closed for life and avoids high speed seals and a vacuum pump, reducing costs and maintenance. The technology can be used to make cheaper hybrid systems, which combine batteries, electric motors and internal combustion engines.

The Kinestor project wants to eventually provide flywheel technology to the everyday market which will deliver up to 30 percent fuel savings at a cost of no more than £1,000. Expect to see this technology first in big heavy buses, ideally suited to regenerate power as they lumber down gradients.
/ENDS