One of the main frustrations in train
travel is the energy lost in braking as a
train pulls into a station. However,
developments in braking technology
has found a way to not only reduce the
energy lost in braking but turn it back
into electrical energy to use whenstarting up again. This could
revolutionise train manufacturing, as
trains will need much less powerful
engines to haul themselves from a
standing start. In fact, regenerative
brakes are just one of a long line of
ways energy can be saved and created.Energy-saving technology
Traditional brakes work by
clamping onto the wheels of the
vehicle and slowing it down
through friction. However, this
wastes energy by turning it into
heat. Regenerative brakes
reverse the electric motor so it
stops producing electrical
energy for forward motion and
instead converts the vehicle’s
momentum into stored energy
that it can use to set off again.
Alternatively, it can send that
power down the track for other
trains to use. This fantastic
innovation not only helps to
stop trains but now creates
power when before it was lost,
making the whole process
much more effi cient.The key to making the most out of the
phenomenal amount of energy
potential in regenerative braking
systems is how to store it. That’s why
places like Philadelphia’s Southeastern
Pennsylvania Transportation Authority
have installed a huge battery that can
hold a megawatt of electricity. That is
enough to boil 7,500 litres (1,981
gallons) of water. Power produced
from regenerative braking or any of
the other energy-gathering
technologies is delivered here. They
can then use this power to run trains
or, if there is more than they need,
they can sell it, so not only are they
saving the environment but making
money too!Designers in Italy, Korea and China have
plans to start putting wind turbines in train
tunnels and on tracks underneath the trains
to harvest energy. As the train whooshes
past, the wind fl ies into the turbines, which
generates electricity using wind power.
Again, this is successfully harnessing
power created by the train to create energy
for use on the track or in the community.An incredible amount of weight and pressure is
placed on train tracks and, although it doesn’t
waste energy, there is still a lot that can be
harvested from it. To gain energy from the
weight of the train, piezoelectric crystals are
placed under the tracks. They have an amazing
property that makes them release an electric
charge when pressure is put on them. As the
train thunders over these crystals, they are
squashed, release a charge and turn that into
electrical energy that can be used in a variety
of areas. Each one can be used time and time
again, providing free, renewable energy.Regenerative
brakes
Battery
Turbines
Sensors
DID YOU KNOW? Friction through driving and braking loses a single InterCity train wheel 68kg (150lb) of steel in its lifetime