Research Vessel Uthörn

After four decades in service to coastal research, in 2023 the AWI replaced the Uthörn (commissioned in 1982) with an innovatively designed successor. The AWI’s new research vessel sets new standards for environmental protection at sea. The Uthörn is the world’s first seaworthy ship powered by green methanol, which allows it to sail the North Sea virtually CO₂-neutrally. In addition, the Uthörn is highly efficient when it comes to heating and cooling: it is the first-ever ship to utilise a water-to-water heat pump, which needs only a fifth of the energy required for a conventional boiler.

The Uthörn’s motors are electric and powered by two specially designed internal-combustion engines that run on methanol, not marine diesel. Though only used experimentally in shipping to date, the green variant of methanol is considered to be a promising option for climate-neutral shipping. Unlike when benzine, diesel or heavy oil is burnt, the combustion of methanol does not release carbon black particles into the atmosphere. One challenge: the environmentally friendly fuel’s energy density, which is only half that of diesel. Accordingly, the new Uthörn has significantly larger fuel tanks than its predecessor, allowing it to bunker enough methanol to maintain a considerablerange.

The old Uthörn consumed ca. 76 metric tons of diesel oil per year on average, producing the equivalent of ca. 243 metric tons of CO₂ emissions. Since the methanol used in the new Uthörn can be produced using green electricity and biomass, it only emits as much CO₂ as was previously removed from the atmosphere. As such, the new ship is virtually climate-neutral.

At first blush, yes. To cover the 48 nautical miles between Bremerhaven and the AWI station on Helgoland, the new Uthörn has to burn roughly 1 metric ton of methanol (or 1.2 m³). Producing that amount of fuel requires ca. 10 MWh of green electricity. A fully electric Uthörn would only need 2.3 MWh of green electricity to cover the same distance. But the batteries would weigh ca. 60 metric tons (or have a volume of ca. 45 m³) and voyages lasting several days would require several of these huge batteries. As a result, a fully electric Uthörn would have to be more than twice as large, consume correspondingly more energy, and its manufacture alone would create a CO₂ footprint so large that it could hardly be compensated for in the course of its service life.

Researchers use the Uthörn year-round to cross the North Sea, and to assess how the sea is changing. To do so, they monitor its physical, chemical and biological status, gleaning valuable long-term data on how this unique regioncan be used sustainably. Many marine biologists learn the tricks of their trade on board the training ship. In addition to collecting samples from the North Sea, the Uthörn regularly goes on transect cruises. Here, the sea is surveyed and analysed at the same group of sites, again and again – akin to cutting it open and taking a look inside. This approach yields valuable time series, allowing researchers to detect even the smallest changes in the environment.