NS is saving energy and going green

For NS (Netherlands Railways), sustainability is becoming more and more important in the way the railway company does business. Recently, Mr. Aad Veenman, CEO of NS, stated new and ambitious goals in this field for 2020. Emissions of CO2 will be reduced by 20%, independent from business growth. The energy saving per seat-kilometre will also be reduced by 20%. From January 2008, the share of sustainable energy has been increased from 5 to 10%.

Carrying 1.1 million people per day over a network of approximately 2,100 kilometres of railway lines, NS provide an efficient and sustainable public transport service in the densely populated Netherlands. Seven days a week, Intercity and Sprinter services run in at half-hourly intervals from early in the morning until midnight. On many routes 15 minute headways form the regular offer until 8pm. Night trains connect the most important cities and Schiphol Amsterdam Airport every hour of the night. Due to the high peak hour share the average load factor of the 260,000 seats is only 30%. On the important Intercity routes the market share of NS during rush hours is 40 to 60%, which underlines the important role trains play in keeping the Dutch on the move.

NS is using approximately 1,300 million kWh of electricity per year, which is comparable with about 420,000 households. Diesel traction plays a very minor role in the NS business, because about 98% of NS customers are carried on electric trains. However, in the Dutch rail freight market, diesel engines do carry most of the traffic. Also, most regional passenger traffic is carried by diesel driven multiple units. NS is involved as supplier of diesel oil for all the private freight and passenger train operating companies.

Energy-efficiency

As one of the bulk consumers of electricity in The Netherlands, NS have a long history of innovative ways to reduce energy consumption. In 1957, NS was the first European railway company to abandon the very inefficient (and polluting) steam traction. In the 70s, experiments with thyristor/chopper controlled power installations on trains started. In 1999, the first long-term agreement about energy efficiency was signed with the Ministry of Economic Affairs. NS promised to increase the energy-efficiency by 10% compared to 1997 and to raise the share of sustainable energy to 5% by 2010.

The energy saving programme NS developed was so successful that in 2005, the energy efficiency already had been improved by 15,6%, far beyond the 10% target set for 2010. Therefore in 2003, Mr. Aad Veenman set a new goal for 2010: to achieve a 20% reduction of energy per seat-kilometre.

The most important share in energy saving is due to the replacement or modernisation of rolling stock. New traction equipment to modern standards reduces the consumption of traction energy. Regenerative braking produces electricity which can be used via the catenary-system by other trains to accelerate. This is the most important reason that the energy-efficiency of newer rolling stock of NS has improved by approximately 30%. The next steps will be to increase the maximum regeneration voltage and to apply optimisation of breaking energy by increasing the share of electric instead of mechanical breaking on certain types of trains.

An energy efficient driving program has been tested and extended since the end of the 90s. Train drivers are informed about fixed points on the line where they can switch off traction current, if the train is running on schedule. As 30% of NS trains arrive >30 seconds too early this is a very important topic to work on. Energy efficient driving has become part of the initial training and ongoing training of train drivers. International cooperation on this field is being performed in the European train driver training program ‘Trainer’.

Together with the Dutch infrastructure manager ProRail tools are being developed to provide relevant information to train drivers to make better decisions using the power equipment. Automatic comparison between the planned timetable and real time running could help to maximize the efficiency of using traction energy without causing delays.

Heating of trains

As heating of trains uses approximately 11% of the total energy, optimising on this field can lead to important savings. Lowering the temperature, decreasing ventilation – of course avoiding unpleasant effects to passenger comfort – and recalibrating of thermostats gave good results on older rolling stock. On Sprinter multiple units, the automatic closing of doors 10 seconds after the last passenger has passed the door was introduced. This prevents from warming the open air, especially during longer intermediate stops and on end stations.

Although it is hard to believe, it has been proven that air-conditioning helps to reduce energy consumption of trains. The fixed windows prevent from losing warmth. But they also streamline the surface of the train, which reduces the energy necessary for gaining and keeping speed. That is why on new and refurbished trains of NS, air-conditioning is or will be provided.

Applying warmth pumps in combination with air-conditioning is expected to lead to another saving of 50% of heat energy.

Important savings were already reached within the process of pre-heating trains and in switching off heating during the shunting process. This has made us clear that giving more and critical attention to daily practices can lead to important and rather easy to reach results.

NS cooperates with infrastructure manager ProRail to develop technical solutions to reduce energy losses in the energy provision. Storage of regenerated braking energy is one of the main topics in this field. So is the heating of points in wintertime, especially during the period that no trains are running.

Last but not least, in our dialogue with the rail industry, energy savings has become an important issue. The new Sprinters being built by Bombardier/Siemens are over 30% more energy efficient than the trains they will replace.

CO2 commitment

These topics from the NS energy saving programme have given and will give an important contribution to the reduction of CO2 emissions. The train in The Netherlands is climate friendly: a passenger kilometre causes an average of 41 gram of CO2, which is one third of the average CO2 emission of a passenger kilometre by car. Nevertheless as mentioned before, NS has promised to have 20% less emissions of CO2 compared to 1990, independent from business growth. NS is the first national company in The Netherlands that stated a CO2 commitment programme.

Apart from the energy saving programme two other measures play an important role in meeting this commitment. Firstly, the load factor of trains has to be improved. Due to the almost 40% peak hour share with train loads over 100%, the average load factor of the 300,000 trains NS is running per week in The Netherlands is only about 30%. Further reduction of the length of trains during evenings and weekends could not only improve the energy-efficiency and CO2 emissions, but also the financial results of NS and the feelings of customers about social security. Nobody benefits from only 100 passengers travelling on a 600 seat train late in the evening.

The second measure to contribute to the reduction of CO2 emissions is the increase of the share of sustainable energy. At the moment the share is 10%, which makes NS one of the five largest private consumers of sustainable electricity in The Netherlands.

The railway system, with its steel wheel on steel track technology and a high share of electric traction, has proven for decades to be an efficient and sustainable form of transport for passengers as well as freight. Innovation and re-thinking are necessary to keep and to develop this position. The world wide discussions about global warming and traffic congestion cannot be met by just offering more of the same. High-speed trains, dedicated freight train routes, segregated tracks for regional and long distance passenger traffic, introducing double-deck trains: they are all answers to society by the European railways to increase capacity and efficiency and increase the share of the railways in mobility. Now it is time to give an answer to the demands for sustainability. That is why NS has added saving energy consumption and reducing emissions of CO2 to its main company targets.

About the author

Jeroen Duijvestijn

Mr. Jeroen Duijvestijn currently works as Manager of Corporate Sustainable Development at Netherlands Railways. He previously worked as a consultant at SMO, a non-profit company. Between 2000 and 2002, Mr. Duijvestijn worked for Trendbox, a market research company where he specialised in trend watching and scenario forecasts.