Economic, Social and Environmental Effects of Electric Traction

Abstract

This study highlights the most important social, economic and enviromental effects of the electric traction. There had been revealed the economic and social benefits, but also the costs involved by the introduction of electric traction in rail and road transport. In rail transport, there are highlighted the additional impacts of electrification on the performance of rail operators. Regarding the environmental impact, it is emphasized also the extent to which the introduction of transport with electric vehicles helps to reduce pollution of the environment and, in particular, of the urban air quality.

Keywords: Electrictractionsocialeconomicenvironment

Introduction

In the current context, in which pollution growth has gained alarming levels, there are looking for

solutions to reduce it. The transport sector, in terms of pollution, is the second greenhouse gas emitting

sector. Meanwhile, transport ranks first position in terms of NOx and CO and the second position on

CO2 emissions, in 2014 accounting for 29% of these emissions (OECD / IEA, 2016).

Introduction or extension of electric traction can significantly reduce emissions, but also generates a

number of other benefits including economic and social ones.

This study revealed also, besides the most important positive effects of electric traction, the problems

facing it.

Literature review

There are many researches in the field of electric traction, most of them regarding technical aspects

and solutions (Alfonsin & al, 2015; Knowles & Morris, 2014). Most of the studies have focused on rail

and urban transport public, who have used and developed electric traction since the late nineteenth

century.

Feng & al. (2013) review energy-saving research focusing on the optimizations of train coasting

schemes, the rational designs and utilizations of track alignments, the ameliorations of train attributes,

and the improvements of system operations. Capasso & al. (1998) analyzed the effect of electric

traction systems on power quality. Battistelli & al. (2004) has studied the interaction between AC and

DC electric railway systems, which cause turbulence and reduce the quality of the network. Feng & al.

(2013) study the energy-saving effect of regenerative braking of metro trains, highlighting also another

positive effect of that, namely preventing the tunnel temperature rising in underground railways to

minimize the energy consumption in air conditioning or ventilating.

There are also some papers that realize comparative analysis regarding different types of vehicles,

respectively between battery electric, hybrid and hydrogen fuel cell vehicles (Offer & al., 2010). The

control strategies used in a hybrid vehicle have a profound impact on the performance and efficiency of

the vehicle (Koch & al., 2011). According to Santiago & al. (2012) study, electric motors are about

three times more efficient than IC engines. Shanglou & al. (2010) presents a rule-based energy

management strategy for a four-wheel drive HEV. Van Vliet & al. (2011) reveal that total cost of

ownership of current electric vehicles is uncompetitive with regular cars and series hybrid cars, but this

cost could become competitive for future wheel motor PHEV.

Economic, environmental and social effects of electric traction

3.1.Benefits and drawbacks of electric traction in rail transport

Electric traction railway history is quite long, starting from 1835, when Davenport built the first car

with electric motor, powered by a battery of galvanic elements. But unfortunately, it is not fully valued

for a long period of time, despite its real benefits. But even from its beginnings, it has been exploited in

electric traction rail. This is the reason why it is used on large scale, based on studies conducted on

electric traction profitability compared with the steam and Diesel traction.

In railway traction widespread use of electric locomotives currently is determined by their several

advantages:

• Do not generate emissions;

• Use electricity generated by different forms of energy, which represents an increasingly part is

renewable energy: hydropower, solar, nuclear, wind, etc;

• They are silent;

• Lower energy costs;

• High efficiency of electric motors;

• Possibility of feeding with required energy for driving from the electricity grid;

• Regenerative breaking that returns energy in the supply system, which increases energy efficiency;

• Lighter than diesel locomotives because they no longer have to incorporate fuel tanks;

• Lower maintenance costs;

• Slight starting easier because the engine develops maximum torque at startup;

• They are more suitable for routes with frequent stops.

Besides other already mentioned benefits, electric traction determines increase in rail traffic speed

and reduces the duration of transport.

During winter, the electrified rail reduces operating costs, by heating with electricity and replacing

the heating oil consumption.

The period of construction and commissioning of the electrification facilities generates a large

number of jobs for these activities.

It should be noted also the drawbacks of introducing electric traction in public urban transport and

rail. The most important problem is that of the costs, especially the high costs caused by investments in

infrastructure and its maintenance and operation.

Regarding costs, rail transport is a major consumer of electricity, which causes a high energy cost.

The highest electricity costs are determined by vehicle traction, but should not be neglected also energy

consumption arising from the infrastructure management activities: lighting, maintenance, operation of

the rail network.

There is a risk of a cost per passenger-km higher in public transport than the cost of own car, if the

use of vehicles for urban transport, like metro, tram, trolley or the railway interurban is low. Hence,

there derives the need, at least in Romania, to educate urban population for the use of public transport.

3.2.Current and future impacts of electric traction in road transport

In Europe there is a policy of developing environmentally friendly transport, which supports, among

other things, the widespread introduction of hybrid and electric vehicles. At Member State level, this

policy is materialized through subsidies to purchase vehicles of this type and tax reductions for owners

of HEVs and EV.

Some countries offer incentives to encourage the use of electric vehicles, resulting in an easier

transition to electric vehicles. In some European countries the grant awarded for holding electric

vehicles can reach values up to 25-30% of the vehicle. In Romania, the maximum subsidy is only about

2100 Euros, in the car scrappage scheme.

In urban areas there can be significantly reduced CO2 emissions by increasing the number of

vehicles based on electric traction. Reducing emissions will have positive effects on human health by

improving air quality in inhabited areas.

Besides the environmental positive effects, there are many other benefits of using electric or hybrid

vehicles (table 1 ).

Electric vehicle manufacturing sector is one of those are hiring. The same trend is found in the

production of rechargeable batteries for such vehicles, as well as in other kinds of companies that

performs additional activities for the production of vehicles or their operation.

Last but not least, companies in these sectors, and government institutions, invest in applied

research, in testing and developing innovations. In the center of interest there are projects aimed at

power electronics, rechargeable batteries improvement and creation of new materials for the

automotive sector.

Unfortunately, these types of vehicles have also a number of drawbacks (table 1 ), most of them

being related to technological limitations.

Currently on the market there are three types of cars that are based on electric traction:

• Vehicles with batteries;

• Hybrid vehicles;

• Fuel cell vehicles.

Hybrid vehicles operate using as source of energy electricity and gas, which means that emissions

are reduced only without being eliminated. Most vehicle manufacturers have at least one model of such

a vehicle.

If there are taken into account the effects of using rechargeable electric vehicles on the national

power grid, the impact is not a major one in terms of energy production. Given that most recharging

will be done during the night, in own garages or parking spaces, when there are loading gaps and no

risk of overloading the network, even with a substantial increase in the number of vehicles of this type,

there will be no negative effects. Problems may arise in some economies of countries with a high level

of industrialization if it significantly increases the number of quick recharge during the day, during

periods of peak loads.

On these vehicles the additional space needed for batteries or hydrogen tanks caused their various

constructive changes. One of the solutions is to integrate the electric motor into the wheel hub.

Phinergy and Alcoa tested a new type of battery made of air and aluminum, which weighs about 100

kg and allows a vehicle to travel more than 1,000 miles after a single charge (Grush, 2014). The

proposed solution currently is a dual system consisting of two batteries, one based on lithium-ion

battery for short distances, for urban areas and the other on air and aluminum for long distances. The

main disadvantage of these batteries is that the air-aluminum battery cannot be recharged. But if users

every or two months refill the water tank, the battery has a shelf life of 20 to 30 years, according to the

designer.

Based on electromagnetic induction, wireless charging is foreseen as a possible solution for

recharging electric vehicle batteries. In 2012, Utah State University has developed a wireless charging

with electric bus prototype with 20% efficiency and 25 kW power load. In Xiangyang, Hubei ZTE

launched in 2014 a route for electric buses with wireless charging efficiency of 90%. In 2013, the

South Korean city of Gumi opened the first route for buses with wireless charging in movement, based

on technology of magnetic fields in resonance.

Conclusions

If in terms of electric traction in rail transport the most acute problems are those related to

investments and costs, in road transport an important part of drawbacks are generated by the limitations

given by existing technologies.

On the market there are many models of hybrid and electric vehicles. Most electric vehicles are

mainly dedicated and used for urban and suburban traffic, given that the autonomy of them is relatively

low. The main concerns of producers are related to increase the efficiency of electric motors and to

shorten the duration of batteries loading. Normal charging is preferable to be accomplished overnight,

providing the necessary energy for driving during the day. But, at the special charging stations,

depending on their power, loading times are significantly lower than the normal load. Unfortunately, in

many countries, the network of recharging points is underdeveloped or non-existent. For this reason it

is necessary toinvest in the necessary equipment for rapid loading of vehicles.

But these drawbacks are counterbalanced by the benefits brought by electric traction: savings from

lower costs of electricity and maintenance and benefits resulting from subsidies, elimination or

reduction the consumption of liquid fossil fuels, reduced noise pollution, and safer operation. More, in

order to reduce pollution, governments provide subsidies to people who buy electric vehicles.

The field of electric vehicles generates also new jobs as those in the production of vehicles and

batteries, in sales and maintenance of them. In the last years, research in this field has made important

steps forward, providing solutions for many problems facing this field.

References

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