Electric Locomotive - Characteristics

Characteristics

One advantage of electrification is the lack of pollution from the locomotives themselves. Electrification also results in higher performance, lower maintenance costs and lower energy costs for electric locomotives.

Power plants, even if they burn fossil fuels, are far cleaner than mobile sources such as locomotive engines. Also the power for electric locomotives can come from clean and/or renewable sources, including geothermal power, hydroelectric power, nuclear power, solar power and wind turbines. Electric locomotives are also quiet compared to diesel locomotives since there is no engine and exhaust noise and less mechanical noise. The lack of reciprocating parts means electric locomotives are easier on the track, reducing track maintenance.

Power plant capacity is far greater than what any individual locomotive uses, so electric locomotives can have a higher power output than diesel locomotives and they can produce even higher short-term surge power for fast acceleration. Electric locomotives are ideal for commuter rail service with frequent stops. They are used on high-speed lines, such as ICE in Germany, Acela in the US, Shinkansen in Japan, China Railway High-speed in China and TGV in France. Electric locomotives are also used on freight routes with consistently high traffic volumes, or in areas with advanced rail networks.

Electric locomotives benefit from the high efficiency of electric motors, often above 90% (not including the inefficiency of generating the electricity). Additional efficiency can be gained from regenerative braking, which allows kinetic energy to be recovered during braking to put some power back on the line. Newer electric locomotives use AC motor-inverter drive systems that provide for regenerative braking.

The chief disadvantage of electrification is the cost for infrastructure (overhead power lines or electrified third rail, substations, and control systems). Public policy in the US currently interferes with electrification—higher property taxes are imposed on privately owned rail facilities if they have electrification facilities. Also, US regulations on diesel locomotives are very weak compared to regulations on automobile emissions or power plant emissions.

In Europe and elsewhere, railway networks are considered part of the national transport infrastructure, just like roads, highways and waterways, so are often financed by the state. Operators of the rolling stock pay fees according to rail use. This makes possible the large investments required for the technically, and in the long-term also, economically advantageous electrification. Because railroad infrastructure is privately owned in the US, railroads are unwilling to make the necessary investments for electrification.