Horace wrote: <snip>. > > > >There also schemes to use high-capacity capacitors for urban buses. Every > >bus stop would be equipped with power mains to recharge the bus while the > >passengers get on and off. This seems impractical to me.
Not so. In Europe there have been bus systems with flywheel energy storage operating for years. Bus stops have a charging pole that can be contacted by a bus to recharge at every stop. In all the discussion about batteries, there is a case to be made for flywheel storage, which has been refined for years. The key issue is very high strength fibers for the flywheels, for the faster the flywheels can go, the higher the energy density, and it is an exponential function of the flywheel speed. Mike Carrell
