Drops typical fuel usage from 500,000 Liters to 475,000 liters – so it can carry coal. What? This is confusing.

The world’s first partly wind-powered bulk carrier sailed to the Port of Newcastle on its maiden voyage. It is the first coal carrier to be powered by hard sail wind power propulsion technology.

Source: Wind Challenger: World’s first partially wind powered cargo ship successfully sailed

Coldstreams Skeptic