[dorlomin]

http://www.guardian.co.uk/environment/2 ... intcmp=122

A fuel-saving flywheel first developed for use in Formula One racing cars, but abandoned before it could be used due to a regulation change by the sport's administrators, will soon be retrofitted to a handful of London buses.

Six prototype buses owned by Go-Ahead, one of the UK's largest buses operators, are currently being fitted with the flywheels for a trial beginning later this year in and around Putney, south-west London.

Williams F1, the Oxfordshire-based racing team behind the technology, predicts that its carbon-composite flywheel could help a city bus reduce its fuel use by as much as 30%.

If successful, and contingent on raising the funding, Go-Ahead says it will consider fitting the flywheels across its 4,000-strong fleet of buses.

"The fuel consumption savings being predicted are attractive even at the lower estimates of around 10%-15%," said Phil Margrave, Go-Ahead's group engineering director.

"Within three months of the trail starting, we'll know if this technology is right for us. There have been lots of flywheel trials over the years, but for various reasons they have failed. Twenty years ago, one came on the market, but it was too noisy and this concerned passengers.

They have failed before but one day someone will get one right.

[Tanada]

This is great! One of the promising ideas I was reading about as early as 1982, hopefully this time it will work as planned.

[Outcast_Searcher]

At the risk of asking a stupid question -- what about safety?

THIS driver/passenger is concerned about safety, however silent the equipment might be. Once one builds a "compartment" sturdy enough to contain the beast under stresses like, say, a major accident -- I wonder what the savings would be.

If this works AND is safe -- then great. It would just seem to be an obvious issue.
(Or as I'm getting older I'm becoming more cowardly or wiser -- not sure which, or maybe both...)

[Tanada]

As I recall it the energy is dissipated pretty darn quickly at need. The system I remember used an 'air brake', the flywheel was spun in a vacuum compartment and in an emergency the compartment flooded with compressed air. The air got heated by the turbulence between fins on the wheel and fins in the chamber shell and absorbed the energy making the flywheel spin as a result. Some of the pictures were pretty dramatic with steel flywheels getting red hot and bearings getting damaged as a result.