CO2 emissions avoided
Our trains have run on 100% green electricity since 2017. As a result, on balance we have reduced our CO2 emissions from train operations to zero, on an annual basis. Every time a person opts for the train instead of travelling by road or air, they help to avoid CO2 emissions. Indeed, if every person in the Netherlands decided to travel only by train, this would reduce the average annual CO2 emissions by 1.5 tonne per individual. This represents more than 20% of CO2 emission reduction per individual in the Netherlands required by 2030 under the European Climate Law.
The train is a more sustainable choice even if other means of transport also transition towards more sustainable fuels. This is due to the low energy and raw material consumption level per passenger kilometre relative to other means of transport, such as cars (including electric cars). However, high average capacity utilisation rates are essential if the train is to maintain its lead.
NS strives for zero-emission, circular and green business practices. While these goals are complementary, sometimes they may also be at odds with each other. For example, when NS wants to build a new roof, do we opt to use recycled materials (circular), to install solar panels or to go for green? Our aim to contribute to the Climate Agreement and the associated targets has made us decide to focus on reducing our CO2 emissions. So that serves as our guide and basis for all our sustainable choices.
Climate-neutral transport, sustainable enterprise
NS is one of the largest electricity consumers in the Netherlands. We use 93% of that energy for running the trains and 7% for operating our stations, offices and workshops. To ensure climate-neutral rail transport, we purchase as much new green electricity from wind farms for our trains as we consume, over the year as a whole.
In addition, in 2019 NS introduced the climate-neutral operation of replacement bus services. We provide replacement bus services when our trains cannot run on specific track sections or at specific times, for example to due repair works, failures or calamities. Touring car suppliers are able to provide climate-neutral transport by deploying buses that run on renewable fuel from waste and residual flows. In the case of scheduled replacement bus services, we deploy buses of this type where possible. However, they are not always available. In such cases, bus suppliers can still compensate by offering sustainable journeys for other clients within the same calendar year. In this way, NS boosts climate-neutral bus transport both under its own contracts and at other transport providers.
NS needs a lot of energy to run its trains and, for example, to heat its stations and other buildings. The consumption of that energy means that we emit CO2. Eneco generates sustainable energy in wind farms on behalf of NS. Throughout 2022, Eneco generated as much energy for NS as the amount we consumed to run our trains.
Energy is not always generated at the moments it is consumed. For example, NS will keep its trains running even when there is no wind. At such times, therefore, we need more energy than we generate. Throughout 2022, we needed more energy than we generated at 40% of the time. There are also moments when we generate as much or even more energy than we consume; for example during windy nights with few trains running. Throughout 2022, we generated as much or even more energy than we needed at 60% of the time.
NS uses three methods to calculate its CO2 emissions:
Market-based: total CO2 emissions from NS's annual energy consumption minus the energy generated for NS on wind farms. Throughout 2022, we used as much energy to run our trains as we generated, so based on this method our emissions from running our trains were practically zero.
Matching: CO2 emissions during the hours we consumed more energy than we generated, i.e. at approximately 40% of the time. During those 40% of all hours in 2022, our emissions amounted to 200 kilotonnes (of which 184 kilotonnes for trains and replacement bus services).
Location-based: total CO2 emissions from the energy NS consumes per year, in a situation in which we do not generate any sustainable energy. This allow for a more meaningful comparison of NS with other organisations in the Netherlands. Based on this calculation method, our total emissions in in 2022 would amount to 495 kilotonnes.
When measuring CO2 emissions, we distinguish between scope 1, 2 and 3 emissions in accordance with the GHG standard.
Scope 1: emissions that we generate ourselves. We have no scope 1 emissions from our trains, but we do generate scope 1 emissions from our gas-heated buildings.
Scope 2: emissions generated in the production of the energy that NS uses. For example, this concerns the electricity from wind farms that we buy to run our trains and the electricity we buy for our offices and buildings.
Scope 3: emissions generated through the business activities of other organisations, for example through the purchase of trains or building materials for station construction. Scope 3 also covers replacement bus services (since NS does not own the buses).
We report on scope 1 and scope 2 emissions, and on scope 3 emissions from replacement bus services. In 2023 we will identify the total of scope 3 emissions, as part of our commitment under the Science Based Target Initiative signed by NS in 2021.
Total CO2 emissions of NS
This is the total of all CO2 emissions from our trains, stations and buildings. Our total CO2 emissions fell in 2022 relative to preceding years.
Kiloton CO2-uitstoot (totaal)*
- * Scope 1, 2 and 3 (replacement bus services)
CO2 emissions from running our trains and from replacement bus services
At NS, we use the term ‘energy efficiency of traction’ to refer to the energy consumption of trains per passenger-kilometre. The following diagram presents the energy efficiency of traction and the total energy consumption of our trains (including replacement bus services). By purchasing sustainable electricity, we have been able to significantly reduce the CO2 emissions from running our trains and from replacement bus services in recent years.
Kiloton CO2-uitstoot (vervoer)*
- * Scope 1, 2 and 3 (replacement bus services)
Emissions from stations and buildings
We are continuing to reduce the energy consumption and the associated CO2 emissions of our stations and buildings. All the gas we have purchased since 2020 comes from green sources (scope 1), while at some locations we also use district heating (scope 2).
Kilotonnes of CO2 emissions (stations and buildings)*
- * Scope 1 and scope 2
The following table shows our CO2 emissions per passenger-kilometre. This makes it possible to compare our emissions with those from other types of transport. The table shows that NS has not produced any CO2 emissions by running trains, on an annual basis, since 2018.
CO2 emissions passenger kilometre*
CO2 emissions per passenger kilometre (gram)
Passenger kilometres in the Netherlands (millions)
- * Scope 1 and scope 2
NS consumes electricity (1,151 GWh), HVO (hydrotreated vegetable oil) diesel (2,0 million litres), heat (21 TJ) and gas (5.4 million m3) for trains, buses, stations, workshops and offices. This works out at a total of 1,230 GWh of energy per year. With our thermal storage system, we generate the equivalent of 21 GWh of heat and cold at six stations.
At NS, we use the term ‘energy efficiency of traction’ to refer to the energy consumption of our trains per passenger-kilometre. The diagram below presents the energy efficiency of traction plus the total energy consumption of our trains (including replacement bus services). The number of passengers in 2022 was 13.3 billion, up 49% compared with 2021. Hence, we also used far less energy per passenger-kilometre in 2022. In 2022, energy consumption per passenger-kilometre was 83.8 Wh.