Director Application Engineering Marine & Offshore at Rolls-Royce Solutions in Friedrichshafen, Germany, Tobias Kohl will speak at the World Yachting Summit in Monaco, scheduled for April 15-17, to talk about the fuels of the future. For years, he has been dedicated to developing alternative systems to reduce the CO₂ footprint through sustainable energy sources and to increasing efficiency with modern propulsion systems, such as hybrid engines and exhaust gas post-treatment practices.

Daily Nautica, one of the media partners of the Monaco event, interviewed him to understand what the sector is working on and his vision regarding sustainable propulsion.

The speech at the World Yachting Summit in Monaco will focus on his field of specialization, nautical fuels: what are the current focus topics of the matter?

The past: fossil based marine gasoil fuels (MGO) with a relatively high sulfur content; today: in tendency fossil based diesel fuel with lower sulfur content and a certain percentage of biofuel (EN590); today/future: is partly renewable fuels, based on organic waste, like HVO or FAME with a significant better CO2 balance. But CO2 neutral fuels like methanol are the future, as long as produced on renewable resources like green hydrogen. Focus for RR/MTU is on “greener” drop in fuels like HVO and on a mid to long term methanol. We do not see hydrogen (because of the storga challenge) or ammonia (because of toxicity) as fuels for our applications.

What are the alternative solutions in the field of engines and nautical propulsion that can make a difference in reducing the CO₂ footprint?

Beside the fuel topic above, we see a very high potential in technologies which are able to increase the energy efficiency/fuel burned: modern common rail combustion engines of the latest generation, like the series 4000M05 or series 2000M07 with best in class fuel consumption in combination with lowest emissions and exhaust gas aftertreatment solutions; intelligent propulsion and energy solutions to optimize the specific fuel consumption like hybrid propulsion and/or the use of variable speed gensets and the use of batteries in combination; optimization of (electrical) energy consumption on board due to the use of low power/more efficient equipment and intelligent power management; use of intelligent products from our NautIQ portfolio (automation) to analyze and optimize the operation profile and behavior; use of more efficient propulsors, like POD propellers, etc.; in general more efficient hulls and measures to increase efficiency of the vessel (shipyard/designer know how).

Do you think that the goal of zero emissions can be reached in a relatively quick time or are the constraints of research and technical innovation still relevant, in your opinion?

It is important to observe new technologies in general on the one side, on the other side we need to be clear in our messages to provide orientation about technical applicability. Our clear focus on methanol is based on deep investigations like use cases for our relevant applications. The technology we’re focusing on (green methanol) is in principle available and is actually made ready for industrial use. Nevertheless we’re facing several challenges: maturity of the technology for big scale commercial application, missing or insufficient regulatory framework or local/global, challenge of infrastructure/availability of green methanol worldwide; acceptance of more fuel volume on board (2x diesel) for the same range/load profile; marked studies show a relevant trend towards Methanol from the year 2028 on.

In addition to the work on engines and energy sources, the issue of exhaust gas post-treatment is also being explored: do you think this is an interesting path?

Efficiency and clean burning technologies have always physical limits. Therefore exhaust gas aftertreatment is a mandatory technology especially for diesel based energy. It is interesting, especially the newest generations of solutions.

What new technologies is your company working on for yachts and superyachts?

We continue to develop modern combustion engines as we still see this technology as key, diesel today and methanol in the future, smart and integrated bridges and automation solutions to make yachting more secure and efficient; system solutions out of one hand, like hybrid, pod, automation, following our “bridge to propeller” strategy.