the ICCT commissioned study investigates three ships using 2019 trade patterns from Automatic Identification System (AIS) data: a 57,000 deadweight tonne (dwt) dry bulk carrier transiting the Chinese coast; a 69,000 dwt ore and coal carrier sailing the North American Great Lakes; and a 7,570 dwt cement carrier operating in Europe’s North and Baltic Seas. These ships represent a range of sizes that are used in short-sea bulk transportation, and they trade in regions that have pledged to achieve net zero emissions economy-wide by a certain date—the United States by 2050, the European Union by 2050, and China by 2060

The study analyses wind as a renewable energy source for maritime transport.  Some barriers identified to the development and uptake of wind propulsion include

1. (Trusted) information on the technologies.

2. Access to capital for building and testing of full scale demonstrators.

3. Incentives to reduce the ships’ CO₂ emissions.  Possible actions to overcome these barriers are proposed, with the development of a standardized assessment method combined with test cases as an important starting point

Tropical oceanic regions have the highest thermal differentials in the world between surface waters and waters at depths of 1000 m. Pacific equatorial waters have the advantage of not being exposed to harsh external force environments such as typhoons and high waves. This situation makes OTEC technology particularly viable in this region. SIDS have an urgent need for reliable green energy and they are excellent ‘testing grounds’ for the further development of OTEC technologies. It is probable that if the proof on concept for OTEC plants in SIDS is realized, there would be a natural progression to larger scale OTEC plants (100 MW to GWs), which would be required larger markets and bigger populations. OTEC can also provide a range of ancillary industries and outputs including fresh water, a range of heating, cooling and refrigeration services, aquaculture and hydroponic agriculture, green hydrogen generation, seawater mineral production, and so on [48]. Models are currently being created for a range of possible new modes of living combining OTEC technologies with on-land technologies producing a blue-green ecologically friendly environment to implement sustainable communities along the tropical belt

A short summary by the KRIOS Research and Development Team, (Korean Research Institute of Ships and Ocean Engineering) to Design an offshore demonstration plant on Ocean Thermal Energy Conversion off the shores of Tarawa Kiribati.  Gross Power output from this plant is estimated to be 1016KW.

..Under the auspice of Korea International Cooperation Agency (KOICA), Korea Research Institute of Ships and Ocean Engineering (KRISO) established the Sustainable Seawater Utilization Academy (SSUA) in 2016, and its 30 graduates formed the SSUA Kiribati Association.  The Ministry of Oceans and Fisheries (MOF) of the Republic of Korea awarded ODA fund to the Association.  By taking advantage of seawater resource and related plants, it was able to provide drinking water and vegetables to the local community from 2018 to 2020. Among the various fields of education and practice provided by SSUA, the Association hope to realize hydroponic cultivation and seawater desalination as a self-support project through a pilot projects. To this end, more than 140 households are benefiting from 3-stage hydroponics, and a seawater desalination system in connection with solar power generation was installed for operation...

A presentation of the OTEC demonstration projects and Research and Development under the Seawater Utilization Plant Research Center(SUPRC), led by the Korea Research Institute of Ships and Ocean Engineering (KRISO) Korea Institute of Ocean Science and Technology (KIOST)

Abstract:.: A lack of affordable and reliable energy in many PSIDS is a development inhibitor. PSIDS are situated within the areas of highest ocean thermal potential in the world. Temperature differences between surface and 1 km depth waters, are in excess of 24°C.  Seawater Utilization technologies can catalyse varied industrial development (e.g., fresh water/aquaculture/agriculture/mineral salts). The KRISO (Korean Research Institute of Ships and Ocean Engineering)-Government of Kiribati OTEC partnership is already 7 years old (2013–2020) and has involved extensive negotiations, awareness raising programmes, and inclusive collaboration. This paper explore a range development opportunities and OTEC technologies for Kiribati. The programme could become a role model for the application of the concept of ‘Interconnected Geoscience..

Abstract. With the issue of peaking carbon dioxide emissions and carbon neutrality increasingly becoming the forefront of international public opinion, changes in the shipping industry are imminent and destined to cause long-term transformation across the entire industry chain, from ship design to maritime operations. Wind energy as a clean energy source has attracted the increasing attention of experts in the shipping field. This paper summarizes the application and development of wind-aided navigation technology for ships represented by rotors, towing kites, wing sails and soft sails, and analyses the constraints of wind-aided navigation technology. The contribution to emission reduction of typical wind-aided navigation methods such as rotors, towing kites, wing sails and soft sails is summarized. Finally, the development suggestions of wind-assisted ship propulsion (WASP) technology are summarized and proposed, which can provide reference for further research and application of this technology.

This chapter specifically puts forward the case for scalable, low-cost ‘proof of concept’ modeling that is urgently required to pave the way for the future market demand of low-emission maritime technology. Four specific mature technologies are examined which have been selected for discussion based on their suitability for application in the unique context of the Pacific region. These four technologies have also been rigorously tested to the point of being extensively developed through both public and private investment initiatives. These investments are further supported by ongoing research efforts from leading German, Dutch, Norwegian and Korean research agencies that have staked a vested interest in the viability of these particular technologies as a concrete tool with which to combat climate change

Abstract: While operating measures and fuel alternatives are suitable in the short-term to meet these novel regulatory constraints, as the use of fossil fuels tapers off, the long-terms solution appears to reside in wind-assisted ships. Consequently, this study aims to identify viable solutions that could reduce emissions, focusing on three prominent technologies, namely sails, rotors and kites. Furthermore, this review provides guidance on the benefits and risks associated with each technology and recommends guidelines for performance prediction and associated constraints. Ultimately, future stakes in wind-assisted propulsion are highlighted, including the need for full-scale validation, the challenge in assessing environmental and economic impact, and the structural issues associated with wind-assisted propulsion systems

The Faculty of Maritime Sciences at Emden/ Leer University of Applied Sciences has developed an automatic control and monitoring system for Flettner rotors.  

Jung and Hwang describes the selection of the working fluid, thermodynamic analysis, and the impact on the Rankine cycle when providing steam to the Combined Ocean Thermal Energy Conversion process. Based on the analysis, C-OTEC is expected to be beneficial for power plants through increased output and plant efficiency. Click here to access article.

The lead licensing agency for OTEC, NOAA’s Office of Ocean and Coastal Resource Management (OCRM), in cooperation with the Coastal Response Research Center (CRRC), held the first in a series of workshops to determine the technical readiness of seven major components of OTEC: 1) cold water pipe; (2) heat exchangers; (3) platform/pipe interface; (4) platform; (5) power cable; (6) platform mooring system; and (7) pumps and turbines. The first workshop, discussed in this report, sought to gather information on the technical readiness of OTEC and evaluate advancements to the technology since the last major attempt, OTEC-1 in 1980.

The qualitative analysis of the technical readiness of OTEC by experts at this workshop suggest that a < 10 MWe floating, closed-cycle OTEC facility is technically feasible using current design, manufacturing, deployment techniques and materials.

Today, many hundreds of multi-hull ships of various designs are being built. This intensive development can be explained by the specific characteristics of multi-hull ships. A multi-hull ship can consist of various numbers of hulls and of hulls of various common or uncommon shapes and/or hulls with small water-plane areas (SWA ships).

The main characteristics of multi-hulls are examined in this paper. Their larger deck area compared to that of mono-hull ships means that all multi-hulls are more economical for most types of “volume” cargoes, including passengers in cabins or saloons, cars and other wheeled vehicles, light containers, laboratories, weapons, aircraft and helicopters, and so on. Similarly, in comparison with corresponding mono-hulls, a sufficiently greater, and simply achievable, transverse stability is the important reason for higher safety in multi-hulls. A larger permissible aspect ratio of these hulls also makes them more energy efficient at higher speeds. The relatively large size of the hull connecting platform is the main reason for higher non-sinkability and higher safety. All multi-hull ships are generally more seaworthy than their mono-hull counterparts. The ships with small waterplane area (SWA) have the best performance characteristics regarding seakeeping. The strength specificity of multi-hulls plays the leading role in determining transverse loads

Ocean thermal energy conversion (OTEC) is a marine renewable energy technology that uses the temperature difference of large volumes of cold deep and warm surface seawater in tropical regions to generate electricity. One anticipated environmental impact of OTEC operations is the entrainment and subsequent mortality of ichthyoplankton (fish eggs and larvae) from the withdrawal of cold and warm seawater. Hauer estimates the potential ichthyoplankton loss from the warm water intake was estimated for a proposed 10 MW OTEC pilot plant offshore Oahu, HI based on ambient vertical distribution data. 

The estimated yearly losses from warm water entrainment of yellowfin and skipjack tuna fish eggs and larvae represent 0.25-0.26 % and 0.09-0.11 % of Hawaii's commercial yellowfin and skipjack tuna industry in 2011 and 2012.