HELSINKI: In January 2021 Norsepower installed two 35x5m Rotor Sails on Sea-Cargo’s RoRo vessel SC Connector operating between Western Norway, the Netherlands and the UK. According to Norsepower Chief Sales Officer Jukka Kuuskoski, after three months the vessel has demonstrated clear operational benefits:
1. Power consistency:
The lesser-known advantage of Rotor Sails is the consistency of power. They provide propulsive power when vessels need it most, even in rough seas and wind, enabling vessels to maintain speed and schedule.
During testing, the two sails on the SC Connector have generated a maximum thrust force equivalent of 7 MW of propeller shaft power. Furthermore, the top speed peaked at 19.6 knots.
The peak speed was achieved from Rotor Sail power (estimated at 7 MW) and approximately 3 MW from the main engine, showing the Rotor Sail generated more power than the installed main engine. This shows the vessel can travel faster with sails than its engine.
2. Improved stability at sea:
The crew of SC Connector noted that the sails have improved the stability of the ship by reducing the roll and enabling higher speed in bad weather.
Being able to complete one round trip on schedule in rough weather can add over 25 percent to the cumulative annual savings of the Rotor Sails. And the combined main engine and Rotor Sails power allowed the vessel to maintain full power in tough conditions.
3. Reduction in fuel consumption:
Every ton of fuel makes over three tons of CO2. Ten tons of fuel were saved during one North Sea crossing from Norway which decreased fuel consumption but also costs.
Investment in clean technology to reduce fuel consumption offers an opportunity to future-proof vessels against inevitable fuel price increases as new fuels enter the market. For example, a 10 percent fuel saving from a Rotor Sail can mean the difference between operating profitably or not as new fuels enter the markets and as costs for carbon emissions are implemented.
4. Compliance with EEXI/CII:
What are the EEXI and CII? The EEXI is a framework for determining the energy efficiency of in-service vessels over 400 GT that fall under MARPOL Annex VI. The EEXI requires ship operators to assess their ships’ energy consumption and CO2 emissions against specific requirements for energy efficiency for each vessel type.
Currently, all wind-assisted propulsion provides a benefit when calculating EEXI grades. For example, to meet EEXI requirements many older vessels will be required to limit their engine power to lower emissions. However, wind-assisted propulsion allows owners to keep powering the main engine as the Rotor Sails enable the reduction of the average main engine power. This contribution to EEXI improvement is also a direct consequence of decreased fuel consumption. The reduced fuel costs make investments in wind propulsion technologies sound, even when looked at on a simple financial basis.
These initial findings from Sea-Cargo will continue to be monitored as these initial results highlight the benefits of wind propulsion. The solution is commercially available, reduces the high carbon intensity gap until new fuels arrive, future proofs assets, saves money now - and has the potential to save more in the future.
Story Type: Comment