“HVO is gentle on the engine”

You've already got quite some experience of HVO. How long have you been using it?  

We started testing HVO two years ago. At that time, we had no experience in terms of performance capability, fuel consumption or local emissions, but we've changed that since. We ran half a million liters of HVO through our freight locomotives in Germany last year. This year, it will be ten million at DB Cargo alone, and as much as 17 million liters across the entire rail group. This way, we're avoiding 50,000 metric tons of CO2e.  

What do you perceive as the greatest benefits?

Our vehicles are in service for an average of 30 to 40 years. This means that many of our locomotives will still be running in 2040. However, we already want to be net-zero carbon in that year, meaning that we have to retrofit many of our vehicles, as it would not be economically feasible or sustainable to procure an entire fleet of new locomotives. However, technical alternatives such as battery technology, hydrogen direct combustion or fuel cells are not yet available and ready to go into production. Trucks are already running on fuel cells, but we're talking about 40-ton vehicles there, and our dual-traction locomotives weigh anywhere up to 4,000 metric tons.  

But we don't want to wait until new technologies for rail freight are ready before starting to protect the climate. That's why HVO is the perfect bridging technology for us until new solutions are available and ready to go into full production. With HVO, we're already saving around 90 percent of CO2e emissions compared with fossil diesel and can make a significant contribution to climate protection. We have hardly any investment costs because we continue to use the existing rolling stock and engines. Another major advantage of using HVO is its versatility: we refuel with HVO wherever and whenever possible. However, where HVO is not available, we can continue to fill up with fossil diesel and mix it in any ratio with the environmentally-friendly biofuel HVO.

What is your experience with HVO?

I can only speak in high tones about HVO. Fuel consumption is identical to fossil diesel. And as well as cutting greenhouse gas emissions by 90 percent, local emissions are also a lot lower. We're talking about up to 55 percent less carbon here, up to 43 percent less nitrogen oxide, up to 61 percent less hydrocarbons and up to 80 percent less particulate.  

And how durable are engines that run on HVO?

There are no problems there at all. We can even say that HVO is gentle on the engine. Together with our colleagues at Rolls-Royce, we disassembled an mtu 8V 4000 R41 engine and found that the engines are burning clear to some extent and that we can rather expect a decrease in wear. Because HVO contains no aromatic compounds, it results in less coking of key engine components and thus longer durability.    

Were there also challenges during the changeover?

The greatest difficulty was actually the uncertainty that existed at the time – and still does. There was little experience of this fuel in our industry. Two years ago, no one was talking about HVO. And since our locomotives are very expensive, any change to the system naturally always carries a financial risk. We've had to undertake a lot of informative discussion and persuasion work to open people's minds to this.

How many of your trains at DB Cargo are currently already running on HVO?  

All 800 of DB Cargo's German diesel locomotives are approved to run on HVO. That said, not all DB Energie service stations – where we get our fuel – have switched to HVO yet. Our locomotives fill up with HVO whenever possible. This year, HVO will represent as much as 20 percent of our total diesel consumption.  

And when will you be at 100 percent?

We're planning to be at 53 percent HVO content by 2028. Whether we will ever reach 100 percent remains to be seen. Because HVO is a bridging technology for us to gain time for the development of new technologies. In the coming years, other technologies will also become attractive – in particular hydrogen direct combustion, ammonia engines. Fuel cells and hybrid traction are also conceivable for future use in rail freight transportation. As soon as technical alternatives emerge that also enable local emission-free operation, these will be given preference. But that will take another five to ten years.  

How much more expensive is HVO than fossil diesel?

Right now, a liter of HVO costs up to 20% more than fossil diesel. That's quite a big ask in a low-margin business like ours. However, we expect prices to fall as demand rises and supplier numbers grow. But HVO will only be able to gain acceptance if there is also a political shift in the ways energy is taxed. HVO is still taxed in Germany like fossil diesel at 47 cents per liter. But if fuels are taxed depending on their CO2 emissions, the prices of fossil diesel and HVO will converge.