Everybody knows the TOYOTA hybridization thermo/electric. Many people think that
a PRIUS consumes less energy, because it makes its own electricity, but they are
wrong, because a lot of energy is lost on that detour.
However this loss is largely compensated by an engine which works more often close
to its maximum efficiency (the excess of power then goes into the battery which returns
it at an appropriate time when the motor is stopped or at very small power). For
a classical car the motor works most of the time between 0 and 20% of its maximum
Although the method is different for a Delta hybridization, the strategy is the same
: to operate the motor at its maximum efficiency as often as possible (maximum efficiency
is not maximum power). At the origin of the Delta hybridization, an observation:
On a modern bike, equipped with many gears, 90% of people, pedal 90% of the time,
between 60 and 70 Rpm - a very narrow range. With a Delta hybridization the motor
transmits its power to the pedalier
with a gear reduction defined to have its regime of maximum efficiency at the said
60-70 Rpm pedalling rate. Thus the cyclist will change his gear ratio as he has always
done for himself, so at the same time the motor operates under the best conditions
to do its work (motor and cyclist work in harmony).
For the technicians: The condition of maximum load is easy to obtain on a vehicle
where the power is never in big excess…
The actual average efficiency of this hybridization is 0.18, and could be easily
increased to 0.25 with a motor a little more sophisticated. This is even better than
that of an Ebike (0.15).
Note : The efficiency of this hybridization, depends mostly on a good management
of the gears rather than the added power of the cyclist. For the minority of cyclists
who have a different pedaling speed, the hybridization could be easily adapted.