The Positive Impact of WASP in the CII score

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An eye-opening paper was presented in the Royal Institute of Naval Architects (RINA) conference ‘Managing CII and Associated Challenges’ in London.

The carbon intensity per ton-mile of transportation work, as represented by the CII and applied for medium sized to large commercial oceangoing cargo ships is considerably affected by each voyage emissions. 

Wind-assisted propulsion (and pure wind propulsion) is based on a broadly present, forceful, and inexhaustible zero emission natural Energy available throughout the oceans for such trading ships, which can be utilized for versatile adjustments of the Annual voyage mix and ship speed, by enhancing the finally attained CII score.

In the paper, the positive impact of WASP (wind propulsion / wind-assisted propulsion) is projected within the well-established Baltic Exchange Indices, which incorporate trading route benchmarks that become the reference base for drafting official voyage or time charter contracts.

A Global trade route statistics pattern is used to approximate the anticipated performance of tramp trading vessels. 

The WASP (wind-assisted propulsion / wind propulsion) impact on the CII score is shown through a WASP-agnostic / Ship-Agnostic approach, so that the shipping community can raise awareness on the qualitative and quantitative elements of performance for a WASP (wind propulsion) system on a ship, while certain examples utilize a Capesize 180 000 DWT bulk carrier example to also indicate expectations when it comes to considering the future low carbon fuel alternatives to MDO, such as methanol and LNG

All WASP (wind propulsion / wind-assisted propulsion) performance benefits calculated for a CII improvement are considering:

  • Long term, macroscopic, waypoints superimposed wind statistics,
  • Shortest (great circle) route trajectories,
  • Passive use of a WASP (wind propulsion) system (i.e. it works automatically when wind blows for net propulsive thrust generation),
  • No speed or course variations at sea.

Therefore, it is reasonable to state that the above indicated CII score contribution of WASP is quite conservative, since a mix of operational activities and strategies on board can further boost wind energy harvesting.

It is imperative for a WASP (wind-assisted propulsion / wind propulsion) system investment to be adjoined with a modern weather routing and forecasting software system on board, so that the voyage is planned as to pre-calculate trajectory options for wind propulsion contribution combined with voyage optimization techniques.

Other voyage-active interventions to boost WASP (wind propulsion) performance are to integrate a WASP system within the main / total propulsion powering system, so that wind energy can be optimally delivered by the holistic/hybrid propulsion management system on board and to improve wind sensing and responsiveness of the WASP (wind-assisted propulsion / wind propulsion) units to their optimal inherent performance parameters.

The last performance assumption is the consideration of a fixed sailing speed throughout the voyage, which is not happening in reality, for many different reasons, such as navigational regional restrictions, charterer instructions to alter speed during voyage, safety of navigation, and others.

The Operator of a WASP (wind propulsion) fitted ship can also attempt to make decisions that can bring commercial diversification, improved competitiveness over certain trades and even utilize the wind energy as a CII ‘bank’, so that period of high wind harvesting for an already well-rated (A or B) ship can be used for either increasing trading speed and hence profitability, or ‘lend’ the over-performance to a pool of commercial trading or placed through carbon credit trading schemes.

As a conclusion, A WASP (wind propulsion / wind-assisted propulsion) agnostic and ship agnostic approach is demonstrating that on Baltic Exchange Indices routes Wind energy available at seas can provide for an average 200-250 kW/WASP unit in favourable wind routes, which – for a propulsion power range of 4000-8000kW representative for Panamax and above ship sizes at a speed of 11-12kn – is a 3-5% power saving potential, while in areas with less wind energy harvesting potential, such average power savings range in a 80-140kW, providing for a smaller 2-3% power saving potential.

For tramp trading ships and for usual sailing speeds of around 10-12 knots, the WASP unit wind power potential for propulsion is in the range of 200kW average according to the global trade route density statistics.

Thanks to such wind energy contribution to propulsion power savings, the CII of an average BCI voyage can be reduced by 2% per installed WASP unit, which means that installing a WASP unit can cover for a yearly reduction factor towards 2024 and further down to 2026, while for Methanol as fuel and LNG as fuel, such contribution is spotted at a 1.77% and 1.47% further reduction respectively.

CHECK HERE OUR WORK ON WIND PROPULSION:  Specializing in Wind Assisted Propulsion – Finocean LTD