LNG-electric cargo ship with unexpected innovations

If the global shipping industry were a country, it would make the list of top 10 polluters in the world. Carbon emissions from shipping have long been comparable to countries like Japan, Germany and the UK.

At the same time, the vast majority of global goods are transported by sea – and the need for shipping is unlikely to decrease. That is why it is so important to find new and innovative methods for reducing emissions from cargo ships.

Liquefied natural gas, or LNG, has long been seen as a lower-carbon alternative to fuel oil. LNG releases less CO₂ and NOₓ than other fossil fuels, although its methane emissions are higher.

Building on innovations in LNG-powered vessels, Egil Ulvan Rederi has built a brand-new type of LNG-electric cargo ship, using cranes and freezer rooms to lower emissions.

The ship, Kristian With, has two on-deck cranes with a total capacity of 70 metric tons. The cranes' control brake system converts its kinetic energy into electric power using a dynamo. This is the same system electric cars and trains use to regenerate energy when braking.

The ship’s LNG tanks, meanwhile, are always kept at -150 °C and used to keep the ship’s freezer room cool, saving 50 kW/h.

Using battery power to supplement its LNG engines, the cargo ship can reduce CO₂ emissions by up to 20 per cent and NOₓ emissions by up to 95 per cent. While in dock, it can run for three to four hours on battery power alone.

Kristian With sails a 16-day return journey along a lengthy stretch of the Norwegian coastline, from Moss in the far southeast to Tromsø north of the Arctic circle.

LNG is a stepping stone towards low-carbon transportation and the growing fleet of LNG-powered cargo ships is growing.

However, if LNG ships are to limit greenhouse gas emissions, they will have to incorporate hybrid technology and other innovations like those used on Kristian With.