Public transport remains a difficult position for communities wishing to move to more sustainable transport modes with reduced carbon footprint. Often the preferred solution is simply perceived as a move to electric drives or hybrid electric vehicles.
However, often overlooked in the conversation on electric vehicles is the reality that vehicles need both energy (to achieve range) and power (for acceleration and load following) to function properly. Whilst the internal combustion engine delivers this functionality well, batteries cannot be optimised for both power and energy at the same time. Thus, there is always a trade-off between the two features... or are flywheels the solution?
There has been much recent work done on the use of flywheel technology for vehicle application, including public transport. Compared to the alternative battery energy systems, flywheels offer much higher power densities as well as higher reliability, longer cycle life without degradation, and reduced ambient temperature concerns. Flywheels are also free of environmental pollutants.
Moreover, integration of these technologies into urban bus routes (which involve large periods of deceleration and acceleration for potential energy recovery and re-use) have proven the technology suitable for high utilisation paths. When combined with inductive power, the modern flywheel can be readily reenergised at passenger stops; thereby offering continuous drive power throughout the day.