Rolls-Royce and Italian yacht builder Sanlorenzo plan to develop and build a large motor yacht with a methanol engine propulsion system able to run carbon-neutrally on ‘green’ methanol, and have signed an exclusive memorandum of understanding (MoU) to this effect for yachts between 40m and 70m.
Powered by two mtu methanol engines based on the Series 4000, the first Sanlorenzo yacht is expected to undertake its maiden voyage in 2026. Methanol is a liquid which is easy to manage, and people are already used to handling it because it is already available in ports today.
Denise Kurtulus, VP Global Marine, Rolls-Royce Power Systems, said: “We’re making shipping more environmentally friendly and easier on the climate, and this agreement is a big step forward in the right direction. Synthetic methanol, produced using electricity generated from renewable sources, is the obvious fuel of the future for many maritime applications – not least yacht propulsion. Sanlorenzo is one of the most innovative yacht builders, making it our partner of choice for this project.”
Massimo Perotti, Executive Chairman and CEO, Sanlorenzo, said: “The introduction of innovations and technologies to reduce the environmental impact of yachts has long been the focus of the Group’s research and development department. The subscription of the agreement with Rolls-Royce and its brand mtu for the integration of methanol propulsion systems on our superyachts represents for our Group a memorable moment, because it gives an extraordinary acceleration to our responsible path and widens our horizons: thanks to the marine use of methanol as a fuel for combustion engines, which allows carbon-neutral powerful propulsion, Sanlorenzo will be able to give the true answer to the demand for sustainability in the yachting sector. I thank Rolls-Royce for choosing Sanlorenzo as a partner for the joint development of a technology that is going to change the paradigm of the yachting industry.”
Dr Otto Preiss, COO and CTO, Rolls-Royce’s Power Systems, said: “Our many years of experience and our extensive expertise in mobile and stationary gas engines will give us a head start in development. We will have methanol-powered propulsion systems in our portfolio for other maritime applications as well as yachts, for example for commercial shipping. These will be part of our ecosystem with sustainable fuels, that we’re currently building. The ecosystem will also include fuel-cell-powered applications as well as electrolysis of green hydrogen, the basic ingredient for green methanol.”
Gianluca Bononi, deputy head, Power Systems marine and MD of Rolls-Royce Solutions Italia, said: “We’re pleased to see Italian yards, which figure prominently in the yacht market, showing a keen interest in sustainable technology. This collaboration with Sanlorenzo demonstrates that the Italian yacht building industry is taking a leading role in climate and environmental protection.”
The plan is to build a large Sanlorenzo luxury yacht tailored to the new type of propulsion system and its requirements. The two partners regard the additional effort as challenging but feasible: because methanol’s energy density is around 50% below that of diesel, the fuel tanks need to be about twice the size to give the vessel the same range as with diesel propulsion. Safety requirements happen to be potentially lower than with other fuels and technologies – because methanol is non-toxic. As a rule of thumb, developers expect the power output of a methanol propulsion system to be about one-third less than that of a diesel system of the same size and mass’
Kurtulus concluded: “In reality, that isn’t terribly important. This is because larger, heavier engines are more likely to be installed in large yachts of 40m to 50m in length than in smaller vessels, and yacht owners who want to be climate-friendly and go easy on the environment aren’t generally looking to wring out the last ounce of power. We’re seeing a trend reversal in the market. In many cases, engine power output in and of itself will no longer be the yardstick. Instead, there will be more and more customers who want to do their bit to protect the climate and now we can also offer them a solution, too. From an engineering perspective, a methanol engine is technically the ideal compromise for the future.”
