By Gary Thomas
Introduction:
Britain Boosts Electric Rail Network
Theory and History behind
Electric Trains
What Are the
Environmental Benefits of Electric Trains?
Issues with Electric Trains
Sources
Introduction:
Britain Boosts Electric Rail Network
The coalition government in the UK has said before that it is the
“greenest government ever”, though this claim has been hard to justify
considering the sometimes drastically differing views on climate of the
Conservative and Liberal Democrat MPs. However, it seems the government
has finally made good on this statement, by announcing huge reforms
within the public transport sector, especially the rail network. The
transport secretary Justine Greening has put forward a £9.4bn, a
significant proportion of which will go towards the electrification of
existing railway lines. Plans include:
- An £800m electrification of the line between Bedford, East
England and Sheffield, Yorkshire, which will also complete the
electrification of connecting lines between the East Midlands and St
Pancreas Station, London.
- Two-thirds of the Welsh population having access to an electric
train via a £600m revamp of the welsh valley lines to Swansea
- An ‘Electric spine’ running down the centre of Britain, linking
Yorkshire, the Midlands and London more than ever before
Given that Britain has the most expensive rail network in Europe, it
is hoped that not only will the further electrification of the rail
network reduce British carbon emissions, but also reduce travelling
costs. These changes are set to be completed by about 2019. But just
how clean are electric trains? This article aims to weigh up the
potential environmental benefits and issues related to electric trains.
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Electric trains are being given a huge monetary
boost by the British Government, in an effort to become a greener
government. Image Credit: photos.com
Theory and History
behind Electric Trains
As the name suggests, electric trains are powered by electricity
rather than the traditional fossil fuels of diesel and coal. The
electricity is initially generated in large-scale power stations, such
as those that supply household electricity. Therefore the electricity
may be generated via any energy source, from coal to hydroelectricity
depending on the power station. This is then transferred to the
locomotive via several different methods.
The two main ways in which an electric train is supplied with power
are rechargeable storage batteries or, more commonly, via a stationary
source, usually an overhead wire or a third rail. The 3rd
rail method usually supplies DC electricity via a rigid conductor along
the side of the railway track. Many overhead wire systems across Europe
use 1500 Volts DC, though in Britain this is used solely in the Tyne
and Wear Metro system.
Once the electricity reaches the train, power is transferred to the
train via a contact conductor, which in an overhead wire configuration
is a ‘pantograph’ (electric rod) attached to the roof of the train.
This then drives the train wheels via the motor.
The first electric passenger train was engineered by Werner Von
Siemens in 1879 and initially electric trains were used solely for
underground systems where pollution from steam trains could be a
hazard.
Italy was the first country to introduce a length of public
electrified train track in 1901, though it wasn’t until the 1960’s that
there was widespread electrification of Europe’s railways.
Electrification of trains was revived in the 1980’s as the Japanese
Shinkansen and French TGV ushered in a new era of high speed trains.
What Are the
Environmental Benefits of Electric Trains?
As with all electric vehicles, there are significant cuts in carbon
emissions when using electric trains as opposed to diesel or steam
driven trains-pollution from the train itself is essentially zero. On
top of this, the electricity is generated from a power plant, and
though the power from these can come from non-renewable sources, this
is still cleaner than using mobile coal and diesel sources. The
Department for Transport (DfT) claims that carbon per passenger mile
from an electric train is up to 35% less than that produced from a
diesel train.
Furthermore, electric trains have lower energy and maintenance
costs, which in turn can lead to cheaper train tickets. Electric trains
also cause less wear to the track due to fewer reciprocating parts in
comparison to traditional trains. A further advantage is that the
electric motors in the train are highly efficient, with efficiency
regularly around 90%. Recent advancements in efficiency include
regenerative braking, which can be used to recover energy from braking,
via motor-inverter drive systems.
Issues with Electric
Trains
A major issue with electric trains is the cost of the
infrastructure, though this is more of an issue in the United States
than it is in Europe, as the infrastructure of the USA rail network is
privately owned, and therefore it is currently still more economically
viable to use predominantly diesel locomotives. Another issue is that
some people believe an increase in overhead cables to be detrimental to
the beauty of the surrounding countryside.
It had been suggested that as the speed of an electric train
increases, then its advantage with regards to sustainability over other
methods of transportation will diminish. However, it has recently been
suggested that an electric train travelling at 300km/h would still have
fewer carbon emissions per passenger than a diesel train traveling at a
speed of 220km per hour.
Sources
http://www.guardian.co.uk/environment/blog/2012/jul/16/electric-trains-diesel-green-carbon
http://www.electric-train.com/
http://www.lowtechmagazine.com/2007/04/planes-on-whe-1.html
http://www.guardian.co.uk/uk/2012/jul/16/9bn-railway-investment-unveiled-cameron
http://www.locomotives-and-trains.com/diesel-electric.html